The CREATE TABLE statement defines a table at the current server.
The definition must include its name and the names and attributes of its columns.
The definition may include other attributes of the table such as primary key.
This statement can be embedded in an application program or issued interactively.
It is an executable statement that can be dynamically prepared.
The privileges held by the authorization ID of the statement must include
at least one of the following:
The privileges held by the authorization ID of the statement must include
at least one of the following:
- The following system authorities:
- *USE to the Create Physical File (CRTPF) command
- *CHANGE to the data dictionary if the library into which the table is
created is an SQL schema with a data dictionary
- Administrative authority
If SQL names are specified and a user profile exists that has the same
name as the library into which the table is created, and that name is different
from the authorization ID of the statement, then the privileges held by the
authorization ID of the statement must include at least one of the following:
- The system authority *ADD to the user profile with that name
- Administrative authority
To define a foreign key, the privileges held by the authorization ID of
the statement must include at least one of the following on the parent table:
- The REFERENCES privilege or object management authority for the table
- The REFERENCES privilege on each column of the specified parent key
- Ownership of the table
- Administrative authority
If the LIKE clause or select-statement is specified, the privileges
held by the authorization ID of the statement must include at least one of
the following on the tables or views specified in these clauses:
- The SELECT privilege for the table or view
- Ownership of the table or view
- Administrative authority
If a distinct type is referenced, the privileges held by the authorization ID of
the statement must include at least one of the following:
- For each distinct type identified in the statement:
- The USAGE privilege on the distinct type, and
- The system authority *EXECUTE on the library containing the distinct type
- Administrative authority
For information on the system authorities corresponding to SQL privileges,
see Corresponding System Authorities When Checking Privileges to a Table or View and Corresponding System Authorities When Checking Privileges to a Distinct Type.
.-,------------------------------------------.
V |
>>-CREATE TABLE--table-name--+-(----+-column-definition----------------------+-+--)-+-->
| +-LIKE--+-table-name-+--+--------------+-+ |
| | '-view-name--' '-copy-options-' | |
| +-unique-constraint----------------------+ |
| +-referential-constraint-----------------+ |
| '-check-constraint-----------------------' |
+-LIKE--+-table-name-+--+--------------+---------------+
| '-view-name--' '-copy-options-' |
'-as-subquery-clause-----------------------------------'
>--+----------------------+------------------------------------->
'-NOT LOGGED INITIALLY-'
.-CARDINALITY-.
.-NOT VOLATILE--+-------------+-.
>--+-------------------------------+--+---------------------+--><
| .-CARDINALITY-. | +-distribution-clause-+
'-VOLATILE--+-------------+-----' '-partitioning-clause-'
column-definition:
|--column-name--+-------------------------------------+--------->
| .-COLUMN-. |
'-FOR--+--------+--system-column-name-'
>--data-type---------------------------------------------------->
.---------------------------------------------------------.
V | (3)
>----+-----------------------------------------------------+-+-------|
+-default-clause--------------------------------------+
| .-GENERATED ALWAYS-----. (1) |
+-+----------------------+-------+------------------+-+
| '-GENERATED BY DEFAULT-' '-identity-options-' |
| (2) |
+-datalink-options------------------------------------+
+-NOT NULL--------------------------------------------+
'-column-constraint-----------------------------------'
data-type:
|--+-built-in-type------+---------------------------------------|
'-distinct-type-name-'
Notes:
- GENERATED can be specified only if the column has a ROWID data type
(or a distinct type that is based on a ROWID data type), or the column is
an identity column.
- The datalink-options can only be specified for DATALINKs and distinct-types
sourced on DATALINKs.
- The same clause must not be specified more than once.
built-in-type:
|--+-+---SMALLINT---+-----------------------------------------------------------------------------------------------+--|
| +-+-INTEGER-+--+ |
| | '-INT-----' | |
| '---BIGINT-----' |
| .-(5,0)------------------------. |
+-+-+-DECIMAL-+-+--+------------------------------+--------------------------------------------------------------+
| | '-DEC-----' | | .-,0--------. | |
| '-NUMERIC-----' '-(--integer--+-----------+--)-' |
| '-, integer-' |
| .-(--53--)------. |
+-+-FLOAT--+---------------+-+-----------------------------------------------------------------------------------+
| | '-(--integer--)-' | |
| +-REAL---------------------+ |
| | .-PRECISION-. | |
| '-DOUBLE--+-----------+----' |
| .-(--1--)-------. |
+-+-+-+-CHARACTER-+--+---------------+-------------------------------+--+----------------+---------------------+-+
| | | '-CHAR------' '-(--integer--)-' | +-FOR BIT DATA---+ | |
| | '-+-+-CHARACTER-+--VARYING-+--(--integer--)--+-----------------+-' +-FOR SBCS DATA--+ | |
| | | '-CHAR------' | '-allocate-clause-' +-FOR MIXED DATA-+ | |
| | '-VARCHAR----------------' '-ccsid-clause---' | |
| | .-(--1M--)-------------. | |
| '-----+-+-CHARACTER-+--LARGE OBJECT-+------+----------------------+--+-----------------+--+----------------+-' |
| | '-CHAR------' | '-(--integer--+---+--)-' '-allocate-clause-' +-FOR SBCS DATA--+ |
| '-CLOB------------------------' +-K-+ +-FOR MIXED DATA-+ |
| +-M-+ '-ccsid-clause---' |
| '-G-' |
| .-(--1--)-------. |
+-+---GRAPHIC----+---------------+----------------------------+--+--------------+--------------------------------+
| | '-(--integer--)-' | '-ccsid-clause-' |
| +-+-GRAPHIC VARYING-+--(--integer--)--+-----------------+---+ |
| | '-VARGRAPHIC------' '-allocate-clause-' | |
| | .-(--1M--)-------------. | |
| '---DBCLOB----+----------------------+--+-----------------+-' |
| '-(--integer--+---+--)-' '-allocate-clause-' |
| +-K-+ |
| +-M-+ |
| '-G-' |
| .-(--1--)-------. |
+-+-+-BINARY--+---------------+------------------------------+-----------------+---------------------------------+
| | | '-(--integer--)-' | | |
| | '-+-BINARY VARYING-+--(--integer--)--+-----------------+-' | |
| | '-VARBINARY------' '-allocate-clause-' | |
| | .-(--1M--)-------------. | |
| '---+-BLOB----------------+----+----------------------+--+-----------------+-' |
| '-BINARY LARGE OBJECT-' '-(--integer--+---+--)-' '-allocate-clause-' |
| +-K-+ |
| +-M-+ |
| '-G-' |
+-+-DATE-------------------+-------------------------------------------------------------------------------------+
| | .-(--0--)-. | |
| +-TIME--+---------+------+ |
| | .-(--6--)-. | |
| '-TIMESTAMP--+---------+-' |
| .-(--200--)-----. |
+---DATALINK--+---------------+--+-----------------+--+--------------+-------------------------------------------+
| '-(--integer--)-' '-allocate-clause-' '-ccsid-clause-' |
'---ROWID--------------------------------------------------------------------------------------------------------'
allocate-clause:
|--ALLOCATE--(integer)------------------------------------------|
ccsid-clause:
.-NOT NORMALIZED-.
|--CCSID--integer--+----------------+---------------------------|
'-NORMALIZED-----'
default-clause:
.-WITH-.
|--+------+--DEFAULT--+------------------------------------------------------+--|
+-constant---------------------------------------------+
+-USER-------------------------------------------------+
+-NULL-------------------------------------------------+
+-CURRENT_DATE-----------------------------------------+
+-CURRENT_TIME-----------------------------------------+
+-CURRENT_TIMESTAMP------------------------------------+
| (1) |
'-cast-function-name--(--+-constant----------+--)------'
+-USER--------------+
+-CURRENT_DATE------+
+-CURRENT_TIME------+
'-CURRENT_TIMESTAMP-'
identity-options:
|--AS IDENTITY--+-------------------------------------------------------+--|
| .-,-------------------------------------------. |
| V .-1----------------. (2) | |
'-(----+-START WITH--+-numeric-constant-+---+------+--)-'
| .-1----------------. |
+-INCREMENT BY--+-numeric-constant-+-+
| .-NO MINVALUE----------------. |
+-+-MINVALUE--numeric-constant-+-----+
| .-NO MAXVALUE----------------. |
+-+-MAXVALUE--numeric-constant-+-----+
| .-NO CYCLE-. |
+-+-CYCLE----+-----------------------+
| .-CACHE--20------. |
+-+-NO CACHE-------+-----------------+
| '-CACHE--integer-' |
| .-NO ORDER-. |
'-+-ORDER----+-----------------------'
column-constraint:
|--+-----------------------------+--+-+-PRIMARY KEY-+--------------+--|
'-CONSTRAINT--constraint-name-' | '-UNIQUE------' |
+-references-clause------------+
'-CHECK--(--check-condition--)-'
Notes:
- This form of the DEFAULT value can only be used with columns that
are defined as a distinct type.
- The same clause must not be specified more than once.
datalink-options:
.-LINKTYPE URL-. .-NO LINK CONTROL--------------------------.
|--+--------------+--+------------------------------------------+--|
'-FILE LINK CONTROL--+-file-link-options-+-'
'-MODE DB2OPTIONS---'
file-link-options:
.--------------------------------------.
V | (1)
|------+-INTEGRITY ALL----------------+---+---------------------|
+-+-READ PERMISSION FS-+-------+
| '-READ PERMISSION DB-' |
+-+-WRITE PERMISSION FS------+-+
| '-WRITE PERMISSION BLOCKED-' |
+-RECOVERY NO------------------+
'-+-ON UNLINK RESTORE-+--------'
'-ON UNLINK DELETE--'
Notes:
- All five file-link-options must be specified, but they can
be specified in any order.
as-subquery-clause:
|--+------------------------------------------------------------+-->
'-(--column-name--+-------------------------------------+--)-'
| .-COLUMN-. |
'-FOR--+--------+--system-column-name-'
>--AS--(--select-statement--)--+-+-WITH NO DATA-+--+--------------+-+--|
| '-WITH DATA----' '-copy-options-' |
'-refreshable-table-options----------'
copy-options:
.-COLUMN ATTRIBUTES-. .-COLUMN-. (1)
|----+-EXCLUDING IDENTITY--+-------------------+-+--+-EXCLUDING--+--------+--DEFAULTS-+---------|
| .-COLUMN ATTRIBUTES-. | | .-COLUMN-. |
'-INCLUDING IDENTITY--+-------------------+-' +-INCLUDING--+--------+--DEFAULTS-+
'-USING TYPE DEFAULTS-------------'
refreshable-table-options:
.-----------------------------------------.
V (2) |
|--+-DATA INITIALLY DEFERRED--+--REFRESH DEFERRED---------+-MAINTAINED BY USER-------------+-+--|
'-DATA INITIALLY IMMEDIATE-' | .-ENABLE QUERY OPTIMIZATION--. |
'-+-DISABLE QUERY OPTIMIZATION-+-'
Notes:
- The clauses can be specified in any order.
- The same clause must not be specified more than once. MAINTAINED
BY USER must be specified.
unique-constraint:
|--+-----------------------------+--+-PRIMARY KEY-+--(---------->
'-CONSTRAINT--constraint-name-' '-UNIQUE------'
.-,-----------.
V |
>----column-name-+--)-------------------------------------------|
referential-constraint:
|--+-----------------------------+--FOREIGN KEY----------------->
'-CONSTRAINT--constraint-name-'
.-,-----------.
V |
>--(----column-name-+--)--references-clause---------------------|
references-clause:
|--REFERENCES--table-name--+-----------------------+------------>
| .-,-----------. |
| V | |
'-(----column-name-+--)-'
.-ON DELETE NO ACTION--------. .-ON UPDATE NO ACTION-. (1)
>--+----------------------------+--+---------------------+-------|
'-ON DELETE--+-RESTRICT----+-' '-ON UPDATE RESTRICT--'
+-CASCADE-----+
+-SET NULL----+
'-SET DEFAULT-'
check-constraint:
|--+-----------------------------+------------------------------>
'-CONSTRAINT--constraint-name-'
>--CHECK--(--check-condition--)---------------------------------|
distribution-clause:
|--IN----nodegroup-name----+-------------------------------------------+--|
| .-,-----------. |
| V | |
'-DISTRIBUTE BY HASH--(----column-name-+--)-'
Notes:
- The ON DELETE and ON UPDATE clauses may be specified in either order.
partitioning-clause:
.-RANGE-.
|--PARTITION BY--+-+-------+--range-partition-spec-+------------|
'-HASH--hash-partition-spec-------'
range-partition-spec:
.-,----------------------------. .-,--------------------------------------------.
V .-NULLS LAST--. | V |
|--(----column-name--+-------------+-+--)--(--+---+---------------------------+--boundary-spec-+---------+--)--|
'-NULLS FIRST-' | '-PARTITION--partition-name-' |
'-boundary-spec--EVERY--(--integer-constant--+--------+--)-'
+-DAY----+
+-DAYS---+
+-MONTH--+
+-MONTHS-+
+-YEAR---+
'-YEARS--'
hash-partition-spec:
.-,-----------.
V |
|--(----column-name-+--)--INTO--integer--PARTITIONS-------------|
boundary-spec:
|--starting-clause--ending-clause-------------------------------|
starting-clause:
.-,------------.
.-FROM-. V | .-INCLUSIVE-.
|--STARTING--+------+--+-(----+-constant-+-+--)-+--+-----------+--|
| +-MINVALUE-+ | '-EXCLUSIVE-'
| '-MAXVALUE-' |
'-+-constant-+-----------'
+-MINVALUE-+
'-MAXVALUE-'
ending-clause:
.-,------------.
.-AT-. V | .-INCLUSIVE-.
|--ENDING--+----+--+-(----+-constant-+-+--)-+--+-----------+----|
| +-MINVALUE-+ | '-EXCLUSIVE-'
| '-MAXVALUE-' |
'-+-constant-+-----------'
+-MINVALUE-+
'-MAXVALUE-'
- table-name
- Names the table. The name, including the implicit or explicit
qualifier, must not identify an alias, file, index, table, or view that already
exists at the current server.
If SQL names were specified, the table will
be created in the schema specified by the implicit or explicit qualifier.
If system names were specified, the table will be created in the schema
that is specified by the qualifier. If not qualified:
- If the value of the CURRENT SCHEMA special register is *LIBL, the table
will be created in the current library (*CURLIB).
- Otherwise, the table will be created in the current schema.
Defines the attributes of a column. There must be at least one column definition
and no more than 8000 column definitions.
The sum of the row buffer byte counts of the columns must not be greater
than 32766 or, if a VARCHAR or VARGRAPHIC column is specified, 32740. Additionally,
if a LOB is specified, the sum of the row data byte counts of the columns
must not be greater than 3 758 096 383 at the time of insert or update. For
information on the byte counts of columns according to data type, see Notes.
- column-name
- Names a column of the table. Do not qualify column-name and
do not use the same name for more than one column of the table or for a system-column-name of the table.
- FOR COLUMN system-column-name
- Provides an i5/OS name for the column. Do not use the same name for
more than one column of the table or for a column-name of the table.
If the system-column-name is
not specified, and the column-name is not a valid system-column-name, a system
column name is generated. For more information about how system column names
are generated, see Rules for Column Name Generation.
- data-type
- Specifies the data type of the column.
- built-in-type
- For built-in-types, use:
- SMALLINT
- For a small integer.
- INTEGER or INT
- For a large integer.
- BIGINT
- For a big integer.
- DECIMAL(integer,integer) or DEC(integer,integer)
- DECIMAL(integer) or DEC(integer)
- DECIMAL or DEC
- For a packed decimal number. The first integer is the precision of the
number; that is, the total number of digits; it can range from 1 to 63. The
second integer is the scale of the number (the number of digits to the right
of the decimal point). It can range from 0 to the precision of the number.
You can use DECIMAL(p) for DECIMAL(p,0), and DECIMAL for
DECIMAL(5,0).
- NUMERIC(integer,integer)
- NUMERIC(integer)
- NUMERIC
- For a zoned decimal number. The first integer is the precision of the
number, that is, the total number of digits; it may range from 1 to 63. The
second integer is the scale of the number, (the number of digits to the right
of the decimal point). It may range from 0 to the precision of the number.
You can use NUMERIC(p) for NUMERIC(p,0), and NUMERIC for
NUMERIC(5,0).
- FLOAT
- For a double-precision floating-point number.
- FLOAT(integer)
- For a single- or double-precision floating-point number, depending on
the value of integer. The value of integer must be in the range 1 through
53. The values 1 through 24 indicate single-precision, the values 25 through
53 indicate double-precision. The default is 53.
- REAL
- For single-precision floating point.
- DOUBLE PRECISION or DOUBLE
- For double-precision floating point.
- CHARACTER(integer) or CHAR(integer)
- CHARACTER or CHAR
- For a fixed-length character string of length integer. The
integer can range from 1 through 32766 (32765 if null capable). If FOR MIXED
DATA or a mixed data CCSID is specified, the range is 4 through 32766 (32765
if null capable). If the length specification is omitted, a length of 1 character
is assumed.
- CHARACTER VARYING (integer) or CHAR
VARYING (integer) or
VARCHAR(integer)
- For a varying-length character string of maximum length integer, which can range from 1 through 32740 (32739 if null capable).
If FOR MIXED DATA or a mixed data CCSID is specified, the range is 4 through
32740 (32739 if null capable).
- CLOB(integer[K|M|G]) or CHAR LARGE
OBJECT(integer[K|M|G]) or CHARACTER LARGE OBJECT(integer[K|M|G])
- CLOB or CHAR LARGE
OBJECT or CHARACTER LARGE OBJECT
- For a character large object string of the specified maximum length.
The maximum length must be in the range of 1 through 2 147 483 647. If FOR
MIXED DATA or a mixed data CCSID is specified, the range is 4 through 2 147
483 647. If the length specification is omitted, a length of 1 megabyte is
assumed. A CLOB is not allowed in a distributed table.
- integer
- The maximum value for integer is 2 147 483 647. The maximum length of
the string is integer.
- integer K
- The maximum value for integer is 2 097 152. The maximum length of the
string is 1024 times integer.
- integer M
- The maximum value for integer is 2 048. The maximum length of the string
is 1 048 576 times integer.
- integer G
- The maximum value for integer is 2. The maximum length of the string
is 1 073 741 824 times integer.
- GRAPHIC(integer)
- GRAPHIC
- For a fixed-length graphic string of length integer, which
can range from 1 through 16383 (16382 if null capable). If the length specification
is omitted, a length of 1 character is assumed.
- VARGRAPHIC(integer) or GRAPHIC
VARYING(integer)
- For a varying-length graphic string of maximum length integer,
which can range from 1 through 16370 (16369 if null capable).
- DBCLOB(integer[K|M|G])
- DBCLOB
- For a double-byte character large object string of the specified maximum
length.
The maximum length must be in the range of 1 through 1 073 741
823. If the length specification is omitted, a length of 1 megabyte is assumed.
A DBCLOB is not allowed in a distributed table.
- integer
- The maximum value for integer is 1 073 741 823. The maximum length of
the string is integer.
- integer K
- The maximum value for integer is 1 028 576. The maximum length of the
string is 1024 times integer.
- integer M
- The maximum value for integer is 1 024. The maximum length of the string
is 1 048 576 times integer.
- integer G
- The maximum value for integer is 1. The maximum length of the string
is 1 073 741 824 times integer.
- BINARY(integer)
- BINARY
- For a fixed-length binary string of length integer. The integer
can range from 1 through 32766 (32765 if null capable). If the length specification
is omitted, a length of 1 character is assumed.
- BINARY VARYING (integer) or
VARBINARY(integer)
- For a varying-length binary string of maximum length integer, which can range from 1 through 32740 (32739 if null capable).
- BLOB(integer[K|M|G]) or BINARY LARGE OBJECT(integer[K|M|G])
- BLOB or BINARY
LARGE OBJECT
- For a binary large object string of the specified maximum length. The
maximum length must be in the range of 1 through 2 147 483 647. If the length
specification is omitted, a length of 1 megabyte is assumed. A BLOB is not
allowed in a distributed table.
- integer
- The maximum value for integer is 2 147 483 647. The maximum length of
the string is integer.
- integer K
- The maximum value for integer is 2 097 152. The maximum length of the
string is 1024 times integer.
- integer M
- The maximum value for integer is 2 048. The maximum length of the string
is 1 048 576 times integer.
- integer G
- The maximum value for integer is 2. The maximum length of the string
is 1 073 741 824 times integer.
- DATE
- For a date.
- TIME
- For a time.
- TIMESTAMP
- For a timestamp.
-
DATALINK(integer) or
DATALINK
- For a DataLink of the specified maximum length. The maximum length must
be in the range of 1 through 32717. If FOR MIXED DATA or a mixed data CCSID
is specified, the range is 4 through 32717. The specified length must be sufficient
to contain both the largest expected URL and any DataLink comment. If the
length specification is omitted, a length of 200 is assumed. A DATALINK is
not allowed in a distributed table.
A DATALINK value is an encapsulated
value with a set of built-in scalar functions. The DLVALUE function creates
a DATALINK value. The following functions can be used to extract attributes
from a DATALINK value.
- DLCOMMENT
- DLLINKTYPE
- DLURLCOMPLETE
- DLURLPATH
- DLURLPATHONLY
- DLURLSCHEME
- DLURLSERVER
A DataLink cannot be part of any index. Therefore, it cannot be
included as a column of a primary key, foreign key, or unique constraint.
- ROWID
- For a row ID. Only one ROWID column is allowed in a table.
A ROWID is not allowed in a partitioned table.
- distinct-type-name
- Specifies that the data type of the column is a distinct type (a user-defined
data type). The length, precision, and scale of the column are respectively
the length, precision, and scale of the source type of the distinct type.
If a distinct type name is specified without a schema name, the distinct type
name is resolved by searching the schemas on the SQL path.
- ALLOCATE(integer)
- Specifies for VARCHAR, VARGRAPHIC, VARBINARY, and LOB types the space
to be reserved for the column in each row. Column values with lengths less
than or equal to the allocated value are stored in the fixed-length portion
of the row. Column values with lengths greater than the allocated value are
stored in the variable-length portion of the row and require additional input/output
operations to retrieve. The allocated value may range from 1 to maximum length
of the string, subject to the maximum row buffer size limit. For information
on the maximum row buffer size, see Maximum row sizes. If FOR MIXED DATA
or a mixed data CCSID is specified, the range is 4 to the maximum length of
the string. If the allocated length specification is omitted, an allocated
length of 0 is assumed. For VARGRAPHIC, the integer is the number of DBCS,
UTF-16, or UCS-2 characters. If a constant is specified for the default value
and the ALLOCATE length is less than the length of the default value, the
ALLOCATE length is assumed to be the length of the default value.
- FOR BIT DATA
- Specifies that the values of the column are not associated with a coded
character set and are never converted. FOR BIT DATA is only valid for CHARACTER
or VARCHAR columns. The CCSID of a FOR BIT DATA column is 65535. FOR BIT DATA
is not allowed for CLOB columns.
- FOR SBCS DATA
- Specifies that the values of the column contain SBCS (single-byte character
set) data. FOR SBCS DATA is the default for CHAR, VARCHAR, and CLOB columns
if the default CCSID at the current server at the time the table is created
is not DBCS-capable or if the length of the column is less than 4. FOR SBCS
DATA is only valid for CHARACTER, VARCHAR, or CLOB columns. The CCSID of FOR
SBCS DATA is determined by the default CCSID at the current server at the
time the table is created.
- FOR MIXED DATA
- Specifies that the values of the column contain both SBCS data and DBCS
data. FOR MIXED DATA is the default for CHAR, VARCHAR, and CLOB columns if
the default CCSID at the current server at the time the table is created is
DBCS-capable and the length of the column is greater than 3. Every FOR MIXED
DATA column is a DBCS-open database field. FOR MIXED DATA is only valid for
CHARACTER, VARCHAR, or CLOB columns. The CCSID of FOR MIXED DATA is determined
by the default CCSID at the current server at the time the table is created.
- CCSID integer
- Specifies that the values of the column contain data of CCSID integer.
If the integer is an SBCS CCSID, the column is SBCS data. If the integer is
a mixed data CCSID, the column is mixed data and the length of the column
must be greater than 3. For character columns, the CCSID must be an SBCS CCSID
or a mixed data CCSID. For graphic columns, the CCSID must be a DBCS, UTF-16,
or UCS-2 CCSID. If a CCSID is not specified for a graphic column, the CCSID
is determined by the default CCSID at the current server at the time the table
is created. For a list of valid CCSIDs, see Appendix E. CCSID values.
CCSID
1208 (UTF-8) or 1200 (UTF-16) data can contain combining characters.
Combining character support allows a resulting character to be comprised of
more than one character. After the first character, up to 300 different non-spacing
accent characters (umlauts, accent, etc.) can follow in the data string.
If the resulting character is one that is already defined in the character
set, that character has more than one representation. Normalization replaces
the string of combining characters with the hex value of the defined character.
This ensures that the same character is represented in a single consistent
way. If normalization is not performed, two strings that look identical will
not compare equal.
- NOT NORMALIZED
- The data should not be normalized when passed from the application.
- NORMALIZED
- The data should be normalized when passed from the application.
- DEFAULT
- Specifies a default value for the column. This clause cannot be specified
more than once in a column-definition. DEFAULT cannot be specified
for a ROWID column or an identity column (a column that is defined AS IDENTITY). The database manager generates
default values for ROWID columns and identity columns. If a value is not specified
following the DEFAULT keyword, then:
- if the column is nullable, the default value is the null value.
- if the column is not nullable, the default depends on the data type of
the column:
| Data type |
Default value |
| Numeric |
0 |
| Fixed-length character or graphic string |
Blanks |
| Fixed-length binary string |
Hexadecimal zeros |
| Varying-length string |
A string length of 0 |
| Date |
The current date at the time of INSERT |
| Time |
The current time at the time of INSERT |
| Timestamp |
The current timestamp at the time of INSERT |
| Datalink |
A value corresponding to DLVALUE('','URL','') |
| distinct-type |
The default value of the corresponding source
type of the distinct type. |
Omission of NOT NULL and DEFAULT from a column-definition is
an implicit specification of DEFAULT NULL.
- constant
- Specifies the constant as the default for the column. The specified
constant must represent a value that could be assigned to the column in accordance
with the rules of assignment as described in Assignments and comparisons.
A floating-point constant must not be used for a SMALLINT, INTEGER, DECIMAL,
or NUMERIC column. A decimal constant must not contain more digits to the
right of the decimal point than the specified scale of the column.
- USER
- Specifies the value of the USER special register at the time of INSERT
or UPDATE as the default value of the column. The data type of the column
must be CHAR or VARCHAR with a length attribute that is greater than or equal
to the length attribute of the USER special register.
- NULL
- Specifies null as the default for the column. If NOT NULL is specified,
DEFAULT NULL must not be specified within the same column-definition.
NULL is the only default value allowed for a datalink column.
- CURRENT_DATE
- Specifies the current date as the default for the column. If CURRENT_DATE
is specified, the data type of the column must be DATE or a distinct type
based on a DATE.
- CURRENT_TIME
- Specifies the current time as the default for the column. If CURRENT_TIME
is specified, the data type of the column must be TIME or a distinct type
based on a TIME.
- CURRENT_TIMESTAMP
- Specifies the current timestamp as the default for the column. If CURRENT_TIMESTAMP
is specified, the data type of the column must be TIMESTAMP or a distinct
type based on a TIMESTAMP.
- cast-function-name
- This form of a default value can only be used with columns defined as
a distinct type, BINARY, VARBINARY, BLOB, CLOB, DBCLOB, DATE, TIME
or TIMESTAMP data types. The following table describes the allowed uses of
these cast-functions.
| Data Type |
Cast Function Name |
| Distinct type N based on a BINARY, VARBINARY,
BLOB, CLOB, or DBCLOB |
BINARY, VARBINARY, BLOB, CLOB, or DBCLOB * |
| Distinct type N based on a DATE, TIME, or
TIMESTAMP |
N (the user-defined cast function that was
generated when N was created) **
or
DATE, TIME, or TIMESTAMP *
|
| Distinct type N based on other data types |
N (the user-defined cast function that was
generated when N was created) ** |
| BINARY, VARBINARY, BLOB, CLOB, or DBCLOB |
BINARY, VARBINARY, BLOB, CLOB, or DBCLOB * |
| DATE, TIME, or TIMESTAMP |
DATE, TIME, or TIMESTAMP * |
|
Notes:
* The name of the function must
match the name of the data type (or the source type of the distinct type)
with an implicit or explicit schema name of QSYS2.
**
The name of the function must match the name of the distinct type for the
column. If qualified with a schema name, it must be the same as the schema
name for the distinct type. If not qualified, the schema name from function
resolution must be the same as the schema name for the distinct type. |
- constant
- Specifies a constant as the argument. The constant must conform to the
rules of a constant for the source type of the distinct type or for the data
type if not a distinct type. For BINARY, VARBINARY, BLOB, CLOB, DBCLOB,
DATE, TIME, and TIMESTAMP functions, the constant must be a string constant.
- USER
- Specifies the value of the USER special register at the time of INSERT
or UPDATE as the default value for the column. The data type of the source
type of the distinct type of the column must be CHAR or VARCHAR with a length
attribute greater than or equal to the length attribute of the USER special
register.
- CURRENT_DATE
- Specifies the current date as the default for the column. If CURRENT_DATE
is specified, the data type of the source type of the distinct type of the
column must be DATE.
- CURRENT_TIME
- Specifies the current time as the default for the column. If CURRENT_TIME
is specified, the data type of the source type of the distinct type of the
column must be TIME.
- CURRENT_TIMESTAMP
- Specifies the current timestamp as the default for the column. If CURRENT_TIMESTAMP
is specified, the data type of the source type of the distinct type of the
column must be TIMESTAMP.
If the value specified is not valid, an error is returned.
- GENERATED
- Specifies that the database manager generates values for the column. GENERATED may
be specified if the column is to be considered an identity column (defined
with the AS IDENTITY clause). It may also be specified if the data type of
the column is a ROWID (or a distinct type that is based on a ROWID). Otherwise,
it must not be specified.
- ALWAYS
- Specifies that the database manager will always generate a value for the column when
a row is inserted into the table. ALWAYS is the recommended value.
- BY DEFAULT
- Specifies that the database manager will generate a value for the column when a row
is inserted only if a value is not specified for the column. If a value is
specified, the database manager uses that value.
For a ROWID column, the database manager uses a
specified value, but it must be a valid unique row ID value that was previously
generated by DB2 UDB for z/OS or DB2 UDB for iSeries.
For an identity column, the database manager inserts
a specified value but does not verify that it is a unique value for the column
unless the identity column has a unique constraint or a unique index that
solely specifies the identity column.
- AS IDENTITY
- Specifies that the column is an identity column for the table. A table
can have only one identity column. An identity column is not allowed in a partitioned table or distributed table. AS IDENTITY can be specified
only if the data type for the column is an exact numeric type with a scale
of zero (SMALLINT, INTEGER, BIGINT, DECIMAL, or NUMERIC with a scale of zero,
or a distinct type based on one of these data types). If a DECIMAL or NUMERIC
data type is specified, the precision must not be greater than 31.
An identity
column is implicitly NOT NULL.
- START WITH numeric-constant
- Specifies the first value that is generated for the identity column.
The value can be any positive or negative value that could be assigned to
the column without non-zero digits existing to the right of the decimal point.
If a value is not explicitly specified when the identity column is defined,
the default is the MINVALUE for an ascending sequence and the MAXVALUE for
a descending sequence. This value is not necessarily the value that a sequence
would cycle to after reaching the maximum or minimum value of the sequence.
The START WITH clause can be used to start a sequence outside the range that
is used for cycles. The range used for cycles is defined by MINVALUE and MAXVALUE.
- INCREMENT BY numeric-constant
- Specifies the interval between consecutive values of the identity column.
The value must not exceed the value of a large integer constant without any
non-zero digits existing to the right of the decimal point. The value must
be assignable to the column. The default is 1.
If the value is zero or positive,
the sequence of values for the identity column ascends. If the value is negative,
the sequence of values descends.
- MAXVALUE numeric-constant
- Specifies the numeric constant that is the maximum value that is generated
for this identity column. This value can be any positive or negative value
that could be assigned to this column, but the value must be greater than
the minimum value.
If a value is not explicitly specified when the identity
column is defined, this is the maximum value of the data type for an ascending
sequence; or the START WITH value, or -1 if START WITH was not specified,
for a descending sequence.
- MINVALUE numeric-constant
- Specifies the numeric constant that is the minimum value that is generated
for this identity column. This value can be any positive or negative value
that could be assigned to this column, but the value must be less than the
maximum value.
If a value is not explicitly specified when the identity
column is defined, this is the START WITH value, or 1 if START WITH was not
specified, for an ascending sequence; or the minimum value of the data type
(and precision, if DECIMAL) for a descending sequence.
- CACHE or NO CACHE
- Specifies whether to keep some preallocated values in memory. Preallocating
and storing values in the cache improves the performance of inserting rows
into a table.
- CACHE integer
- Specifies the number of values of the identity column sequence that the database manager preallocates
and keeps in memory. The minimum value that can be specified is 2, and the
maximum is the largest value that can be represented as an integer. The default
is 20.
In certain situations, such as system failure, all cached
identity column values that have not been used in committed statements are
lost, and thus, will never be used. The value specified for the CACHE option
is the maximum number of identity column values that could be lost in these
situations.
- NO CACHE
- Specifies that values for the identity column are not preallocated.
- CYCLE or NO CYCLE
- Specifies whether this identity column should continue to generate values
after reaching either the maximum or minimum value of the sequence.
- CYCLE
- Specifies that values continue to be generated for this column after
the maximum or minimum value has been reached. If this option is used, after
an ascending sequence reaches the maximum value of the sequence, it generates
its minimum value. After a descending sequence reaches its minimum value of
the sequence, it generates its maximum value. The maximum and minimum values
for the column determine the range that is used for cycling.
When CYCLE
is in effect, duplicate values can be generated by the database manager for an identity
column. If a unique constraint or unique index exists on the identity column,
and a non-unique value is generated for it, an error occurs.
- NO CYCLE
- Specifies that values will not be generated for the identity column
once the maximum or minimum value for the sequence has been reached. This
is the default.
- ORDER or NO ORDER
- Specifies whether the identity values must be generated in order of
request.
- ORDER
- Specifies that the values are generated in order of request.
- NO ORDER
- Specifies that the values do not need to be generated in order of request.
This is the default.
- datalink-options
- Specifies the options associated with a DATALINK data type.
- LINKTYPE URL
- Defines the type of link as a Uniform Resource Locator (URL).
- NO LINK CONTROL
- Specifies that there will not be any check made to determine that the
linked files exist. Only the syntax of the URL will be checked. There is no
database manager control over the linked files.
- FILE LINK CONTROL
- Specifies that a check should be made for the existence of the linked
files. Additional options may be used to give the database manager further
control over the linked files.
If FILE LINK CONTROL is specified, each file
can only be linked once. That is, its URL can only be specified in a single
FILE LINK CONTROL column in a single table.
- file-link-options
- Additional options to define the level of database manager control of
the linked files.
- INTEGRITY
- Specifies the level of integrity of the link between a DATALINK value
and the actual file.
- ALL
- Any file specified as a DATALINK value is under the control of the database
manager and may NOT be deleted or renamed using standard file system programming
interfaces.
- READ PERMISSION
- Specifies how permission to read the file specified in a DATALINK value
is determined.
- FS
- The read access permission is determined by the file system permissions.
Such files can be accessed without retrieving the file name from the column.
- DB
- The read access permission is determined by the database. Access to
the file will only be allowed by passing a valid file access token, returned
on retrieval of the DATALINK value from the table, in the open operation.
If READ PERMISSION DB is specified, WRITE PERMISSION BLOCKED must be specified.
- WRITE PERMISSION
- Specifies how permission to write to the file specified in a DATALINK
value is determined.
- FS
- The write access permission is determined by the file system permissions.
Such files can be accessed without retrieving the file name from the column.
- BLOCKED
- Write access is blocked. The file cannot be directly updated through
any interface. An alternative mechanism must be used to perform updates to
the information. For example, the file is copied, the copy updated, and then
the DATALINK value updated to point to the new copy of the file.
- RECOVERY
- Specifies whether or not the database manager will support point in time recovery
of files referenced by values in this column.
- NO
- Specifies that point in time recovery will not be supported.
- ON UNLINK
- Specifies the action taken on a file when a DATALINK value is changed
or deleted (unlinked). Note that this is not applicable when WRITE PERMISSION
FS is used.
- RESTORE
- Specifies that when a file is unlinked, the DataLink File Manager will
attempt to return the file to the owner with the permissions that existed
at the time the file was linked. In the case where the user is no longer registered
with the file server, the result depends on the file system that contains
the files. If the files are in the AIX® file system, the owner is "dfmunknown".
If the files are in IFS, the owner is QDLFM. This can only be specified when
INTEGRITY ALL and WRITE PERMISSION BLOCKED are also specified.
- DELETE
- Specifies that the file will be deleted when it is unlinked. This can
only be specified when READ PERMISSION DB and WRITE PERMISSION BLOCKED are
also specified.
- MODE DB2OPTIONS
- This mode defines a set of default file link options. The defaults defined
by DB2OPTIONS are:
- INTEGRITY ALL
- READ PERMISSION FS
- WRITE PERMISSION FS
- RECOVERY NO
- NOT NULL
- Prevents the column from containing null values. Omission of NOT NULL
implies that the column can be null.
- column-constraint
-
- CONSTRAINT constraint-name
- Names the constraint. A constraint-name must not identify a
constraint that was previously specified in the CREATE TABLE statement and
must not identify a constraint that already exists at the current server.
If the clause is not specified, a unique constraint name is generated by the
database manager.
- PRIMARY KEY
- Provides a shorthand method of defining a primary key composed of a
single column. Thus, if PRIMARY KEY is specified in the definition of column
C, the effect is the same as if the PRIMARY KEY(C) clause is specified as
a separate clause.
This clause must not be specified in more than one column
definition and must not be specified at all if the UNIQUE clause is specified
in the column definition. The column must not be a LOB or DATALINK column.
When a primary key is added, a CHECK constraint is implicitly added
to enforce the rule that the NULL value is not allowed in the column that
makes up the primary key.
- UNIQUE
- Provides a shorthand method of defining a unique constraint composed
of a single column. Thus, if UNIQUE is specified in the definition of column
C, the effect is the same as if the UNIQUE (C) clause is specified as a separate
clause.
This clause cannot be specified more than once in a column definition
and must not be specified if PRIMARY KEY is specified in the column definition.
The column must not be a LOB or DATALINK column.
- references-clause
- The references-clause of a column-definition provides
a shorthand method of defining a foreign key composed of a single column.
Thus, if a references-clause is specified in the definition of column C, the
effect is the same as if that references-clause were specified as part of
a FOREIGN KEY clause in which C is the only identified column. The references-clause is not allowed if the table is a partitioned table or
a distributed table.
- CHECK(check-condition)
- The CHECK(check-condition) of a column-definition provides
a shorthand method of defining a check constraint whose check-condition only references a single column. Thus, if CHECK is specified in the
column definition of column C, no columns other than C can be referenced in
the check-condition of the check constraint. The effect is the same
as if the check constraint were specified as a separate clause.
ROWID or
DATALINK with FILE LINK CONTROL columns cannot be referenced in a CHECK constraint.
For additional restrictions see, check-constraint.
- table-name or view-name
- Specifies that the columns of the table have exactly the same name and
description as the columns of the identified table (table-name) or
view (view-name). The name must identify a table or view that exists
at the current server.
The use of LIKE is an implicit definition of n
columns, where n is the number of columns in the identified table or view.
The implicit definition includes the following attributes of the n columns
(if applicable to the data type):
- Column name (and system column name)
- Data type, length, precision, and scale
- CCSID
If the LIKE clause is specified immediately following the table-name and not enclosed in parenthesis, the following column attributes
are also included, otherwise they are not included (the default value and
identity attributes can also be controlled by using the copy-options):
- Default value, if a table-name is specified (view-name is
not specified)
- Nullability
- Identity attributes
- Column heading and text (see LABEL)
The implicit definition does not include any other optional attributes
of the identified table or view. For example, the new table does not automatically
include primary keys, foreign keys, or triggers. The new table has these and
other optional attributes only if the optional clauses are explicitly specified.
If the specified table or view is a non-SQL created physical file or
logical file, any non-SQL attributes are removed. For example, the date and
time format will be changed to ISO.
- column-name
- Names a column in the table. If a list of column names is
specified, it must consist of as many names as there are columns in the result
table of the select-statement. Each column-name must be
unique and unqualified. If a list of column names is not specified, the
columns of the table inherit the names of the columns of the result table
of the select-statement.
A list of column names must be specified
if the result table of the select-statement has duplicate
column names or an unnamed column. An unnamed column is a column derived
from a constant, function, expression, or set operation (UNION or INTERSECT)
that is not named using the AS clause of the select list.
- FOR COLUMN system-column-name
- Provides an i5/OS name for the column. Do not use the same name for
more than one column of the table or for a column-name of the table.
If
the system-column-name is not specified, and the column-name is not
a valid system-column-name, a system column name is generated. For
more information about how system column names are generated, see Rules for Column Name Generation.
- select-statement
- Specifies that the columns of the table have the same name and description
as the columns that would appear in the derived result table of the select-statement if the select-statement were to be executed. The use of AS (select-statement) is an implicit definition of n columns for
the table, where n is the number of columns that would result from
the select-statement.
The implicit definition includes the following
attributes of the n columns (if applicable to the data type):
- Column name (and system column name)
- Data type, length, precision, and scale
- CCSID
- Nullability
- Column heading and text (see LABEL)
The following attributes are not included (the default value and
identity attributes may be included by using the copy-options):
- Default value
- Identity attributes
The implicit definition does not include any other optional attributes
of the identified table or view. For example, the new table does not automatically
include a primary key or foreign key from a table. The new table has these
and other optional attributes only if the optional clauses are explicitly
specified.
The select-statement must not refer to variables
or include parameter markers.
The select-statement must
not contain a PREVIOUS VALUE or a NEXT VALUE expression. The UPDATE, READ
ONLY, and OPTIMIZE clauses may not be specified.
- WITH DATA
- Specifies that the select-statement is executed. After the
table is created, the result table rows of the select-statement are
automatically inserted into the table.
- WITH NO DATA
- Specifies that the select-statement is used only to define
the attributes of the new a table. The table is not populated using the results
of the select-statement.
- refreshable-table-options
- Specifies that the table is a materialized query table and
the REFRESH TABLE statement can be used to populate the table with the results
of the select-statement.
A materialized query table whose select-statement contains a GROUP BY clause is summarizing data from
the tables referenced in the select-statement. Such a materialized
query table is also known as a summary table. A summary table is
a specialized type of materialized query table.
When a materialized
query table is defined, the following select-statement restrictions
apply:
- The select-statement cannot contain a reference to another materialized
query table or to a view that refers to a materialized query table.
- The select-statement cannot contain a reference to a declared
global temporary table, a table in QTEMP, a program-described file, or a non-SQL
logical file in the FROM clause.
- The select-statement cannot contain a reference to
a view that references another materialized query table or a declared global
temporary table. When a materialized query table is defined with ENABLE QUERY
OPTIMIZATION, the select-statement cannot contain a reference to
a view that contains one of the restrictions from the following paragraph.
- The select-statement cannot contain an expression with a DataLink
or a distinct type based on a DataLink where the DataLink is FILE LINK CONTROL.
- The select-statement cannot contain a result column that is a
not an SQL data type, such as binary with precision, DBCS-ONLY, or DBCS-EITHER.
When a materialized query table is defined with ENABLE QUERY OPTIMIZATION,
the following additional select-statement restrictions apply:
- Must not include any special registers.
- Must not include any non-deterministic functions.
- The ORDER BY clause is allowed, but is only used by REFRESH. It may improve
locality of reference of data in the materialized query table.
- If the subselect references a view, the select-statement in the view definition must satisfy the preceding restrictions.
- DATA INITIALLY DEFERRED
- Specifies that the data is not inserted into the materialized query
table when it is created. Use the REFRESH TABLE statement to populate the
materialized query table, or use the INSERT statement to insert data into
a materialized query table.
- DATA INITIALLY IMMEDIATE
- Specifies that the data is inserted into the materialized query table
when it is created.
- REFRESH DEFERRED
- Specifies that the data in the table can be refreshed at any time using
the REFRESH TABLE statement. The data in the table only reflects the result
of the query as a snapshot at the time when the REFRESH TABLE statement is
processed or when it was last updated.
- MAINTAINED BY USER
- Specifies that the materialized query table is maintained by the user.
The user can use INSERT, DELETE, UPDATE, or REFRESH TABLE statements on the
table.
- ENABLE QUERY OPTIMIZATION or DISABLE
QUERY OPTIMIZATION
- Specifies whether this materialized query table can be used for optimization.
The default is ENABLE QUERY OPTIMIZATION.
- ENABLE QUERY OPTIMIZATION
- Specifies that the materialized query table can be used for query optimization.
If the select-statement specified does not satisfy the restrictions
for query optimization, an error is returned.
- DISABLE QUERY OPTIMIZATION
- Specifies that the materialized query table cannot be used for query
optimization. The table can still be queried directly.
- INCLUDING IDENTITY COLUMN ATTRIBUTES or EXCLUDING IDENTITY COLUMN ATTRIBUTES
- Specifies whether identity column attributes are inherited.
- INCLUDING IDENTITY COLUMN ATTRIBUTES
- Specifies that the table inherits the identity attribute, if any, of
the columns resulting from select-statement, table-name,
or view-name. In general, the identity attribute is copied if the
element of the corresponding column in the table, view, or select-statement is the name of a table column or the name of a view column that directly
or indirectly maps to the name of a base table column with the identity attribute.
If the INCLUDING IDENTITY COLUMN ATTRIBUTES clause is specified with the AS select-statement clause, the columns of the new table do not inherit
the identity attribute in the following cases:
- The select list of the select-statement includes multiple instances
of an identity column name (that is, selecting the same column more than once).
- The select list of the select-statement includes multiple identity
columns (that is, it involves a join).
- The identity column is included in an expression in the select list.
- The select-statement includes a set operation (UNION or INTERSECT).
If INCLUDING IDENTITY is not specified, the table will not have an
identity column.
- EXCLUDING IDENTITY COLUMN ATTRIBUTES
- Specifies that the table does not inherit the identity attribute, if
any, of the columns resulting from the fullselect, table-name, or view-name.
- EXCLUDING COLUMN DEFAULTS or INCLUDING
COLUMN DEFAULTS or USING TYPE DEFAULTS
- Specifies whether column defaults are inherited.
- EXCLUDING COLUMN DEFAULTS
- Specifies that the column defaults are not inherited from the definition
of the source table. The default values of the column of the new table are
either null or there are no default values. If the column can be null, the
default is the null value. If the column cannot be null, there is no default
value, and an error occurs if a value is not provided for a column on INSERT
for the new table.
- INCLUDING COLUMN DEFAULTS
- Specifies that the table inherits the default values of the columns
resulting from the select-statement, table-name, or view-name. A default value is the value assigned to a column when a value
is not specified on an INSERT.
Do not specify INCLUDING COLUMN DEFAULTS,
if you specify USING TYPE DEFAULTS.
If INCLUDING COLUMN DEFAULTS is
not specified, the default values are not inherited.
- USING TYPE DEFAULTS
- Specifies that the default values for the table depend on the data type
of the columns that result from the select-statement, table-name, or view-name. If the column is nullable, then the default
value is the null value. Otherwise, the default value is as follows:
| Data type |
Default value |
| Numeric |
0 |
| Fixed-length character or graphic string |
Blanks |
| Fixed-length binary string |
Hexadecimal zeros |
| Varying-length string |
A string length of 0 |
| Date |
The current date at the time of INSERT |
| Time |
The current time at the time of INSERT |
| Timestamp |
The current timestamp at the time of INSERT |
| Datalink |
A value corresponding to DLVALUE('','URL','') |
| distinct-type |
The default value of the corresponding source
type of the distinct type. |
Do not specify USING TYPE DEFAULTS if INCLUDING COLUMN
DEFAULTS is specified.
- CONSTRAINT constraint-name
- Names the constraint. A constraint-name must not identify a
constraint that was previously specified in the CREATE TABLE statement and
must not identify a constraint that already exists at the current server.
If the clause is not specified, a unique constraint name is generated by the
database manager.
- PRIMARY KEY(column-name,...)
- Defines a primary key composed of the identified columns. A table can
only have one primary key. Thus, this clause cannot be specified more than
once and cannot be specified at all if the shorthand form has been used to
define a primary key for the table. The identified columns cannot be the same
as the columns specified in another UNIQUE constraint specified earlier in
the CREATE TABLE statement. For example, PRIMARY KEY(A,B) would not be allowed
if UNIQUE (B,A) had already been specified.
Each column-name must be an unqualified name that identifies a column of the table. The
same column must not be identified more than once. The column must not be
a LOB or DATALINK column. The number of identified columns must not exceed
120, and the sum of their byte counts must not exceed 32766-n, where n is the number of columns specified
that allow nulls. For information on byte-counts see Table 52.
The unique index is created as part of the system physical file, not
a separate system logical file. When a primary key is added, a CHECK constraint
is implicitly added to enforce the rule that the NULL value is not allowed
in any of the columns that make up the primary key.
- UNIQUE (column-name,...)
- Defines a unique constraint composed of the identified columns. The
UNIQUE clause can be specified more than once. The identified columns cannot
be the same as the columns specified in another UNIQUE constraint or PRIMARY
KEY that was specified earlier in the CREATE TABLE statement. For determining
if a unique constraint is the same as another constraint specification, the
column lists are compared. For example, UNIQUE (A,B) is the same as UNIQUE
(B,A).
Each column-name must be an unqualified name that identifies
a column of the table. The same column must not be identified more than once.
The column must not be a LOB or DATALINK column. The number of identified
columns must not exceed 120, and the sum of their byte counts must not exceed
32766-n, where n is the number
of columns specified that allows nulls. For information on byte-counts see Table 52.
A unique index on the identified column is created
during the execution of the CREATE TABLE statement. The unique index is created
as part of the system physical file, not as a separate system logical file.
- CONSTRAINT constraint-name
- Names the constraint. A constraint-name must not identify a
constraint that was previously specified in the CREATE TABLE statement and
must not identify a constraint that already exists at the current server.
If the clause is not specified, a unique constraint name is generated by the
database manager.
- FOREIGN KEY
- Each specification of the FOREIGN KEY clause defines a referential constraint. FOREIGN KEY is not allowed if the table is a partitioned table.
- (column-name,...)
- The foreign key of the referential constraint is composed
of the identified columns. Each column-name must be an unqualified
name that identifies a column of the table. The same column must not be identified
more than once. The column must not be a LOB or DATALINK column. The number
of identified columns must not exceed 120, and the sum of their lengths must
not exceed 32766-n, where n is
the number of columns specified that allow nulls.
- REFERENCES table-name
- The table-name specified in a REFERENCES clause must identify
the table being created or a base table that already exists at the application server,
but it must not identify a catalog table, a global temporary
table, a partitioned table, or a distributed table.
A referential constraint
is a duplicate if its foreign key, parent key, and
parent table are the same as the foreign key, parent key, and parent table
of a previously specified referential constraint. Duplicate referential constraints
are allowed, but not recommended.
Let T2 denote the identified parent
table and let T1 denote the table being created.
The specified foreign
key must have the same number of columns as the parent key of T2. The description
of the nth column of the foreign key and the description
of the nth column of that parent key must have identical
data types, lengths, and CCSIDs.
- (column-name,...)
- The parent key of the referential constraint is composed
of the identified columns. Each column-name must be an unqualified
name that identifies a column of T2. The same column must not be identified
more than once. The column must not be a LOB or DATALINK column. The number
of identified columns must not exceed 120, and the sum of their byte counts
must not exceed 32766-n, where n is the number of columns specified that allow nulls. For information
on byte-counts see Table 52.
The list of column names must
be identical to the list of column names in the primary key of T2 or a UNIQUE
constraint that exists on T2. The names need not be specified in the same
order as in the primary key; however, they must be specified in corresponding
order to the list of columns in the foreign key clause. If a column
name list is not specified, then T2 must have a primary key. Omission of the
column name list is an implicit specification of the columns of that primary
key.
The referential constraint specified by a FOREIGN KEY clause
defines a relationship in which T2 is the parent and T1 is the dependent.
- ON DELETE
- Specifies what action is to take place on the dependent tables when
a row of the parent table is deleted. There are five possible actions:
- NO ACTION (default)
- RESTRICT
- CASCADE
- SET NULL
- SET DEFAULT
SET NULL must not be specified unless some column of the foreign key
allows null values.
CASCADE must not be specified if T1 contains a DataLink
column with FILE LINK CONTROL.
The delete rule applies when a row of
T2 is the object of a DELETE or propagated delete operation and that row has
dependents in T1. Let p denote such a row of T2.
- If RESTRICT or NO ACTION is specified, an error occurs and no rows are
deleted.
- If CASCADE is specified, the delete operation is propagated to the dependents
of p in T1.
- If SET NULL is specified, each nullable column of the foreign key of each
dependent of p in T1 is set to null.
- If SET DEFAULT is specified, each column of the foreign key of each dependent
of p in T1 is set to its default value.
- ON UPDATE
- Specifies what action is to take place on the dependent tables when
a row of the parent table is updated.
The update rule applies when a row
of T2 is the object of an UPDATE or propagated update operation and that row
has dependents in T1. Let p denote such a row of T2.
- If RESTRICT or NO ACTION is specified, an error occurs and no rows are
updated.
- CONSTRAINT constraint-name
- Names the check constraint. A constraint-name must not identify
a constraint that was previously specified in the CREATE TABLE statement and
must not identify a constraint that already exists at the current server.
If the clause is not specified, a unique constraint name is generated by the
database manager.
- CHECK (check-condition)
- Defines a check constraint. At any time, the check-condition must
be true or unknown for every row of the table.
The check-condition is
a search-condition except:
- It can only refer to columns of the table
- It cannot reference ROWID or DATALINK with FILE LINK CONTROL columns.
- It must not contain any of the following:
- Subqueries
- Aggregate functions
- Variables
- Parameter markers
- Complex expressions that contain LOBs (such as concatenation)
- CURRENT_DEGREE, CURRENT SCHEMA, CURRENT SERVER, CURRENT PATH,
CURRENT DEBUG MODE, SESSION_USER, SYSTEM_USER, and USER special registers
- CURRENT DATE, CURRENT TIME, and CURRENT TIMESTAMP special registers
- User-defined functions other than functions that were implicitly generated
with the creation of a distinct type
- NOW, CURDATE, and CURTIME scalar functions
- DBPARTITIONNAME scalar function
- ATAN2, DIFFERENCE, RADIANS, RAND, and SOUNDEX scalar functions
- DLVALUE, DLURLPATH, DLURLPATHONLY, DLURLSERVER, or DLURLSCHEME scalar
functions
- DLURLCOMPLETE scalar function (for DataLinks with an attribute of FILE
LINK CONTROL and READ PERMISSION DB)
- DECRYPT_BIT, DECRYPT_BINARY, DECRYPT_CHAR, DECRYPT_DB, ENCRYPT_RC2,
ENCRYPT_TDES, and GETHINT
- DAYNAME, MONTHNAME, NEXT_DAY, and VARCHAR_FORMAT
- INSERT, REPEAT, and REPLACE
- GENERATE_UNIQUE and RAISE_ERROR
For more information about search-condition, see Search conditions.
For more information about check constraints involving LOB data types and
expressions, see the Database Programming book.
Any changes made to the table by INSERT, DELETE, or UPDATE statements in
the same unit of work after the table is created by this statement are not
logged (journaled).
At the completion of the current unit of work, the NOT LOGGED INITIALLY
attribute is deactivated and all operations that are done on the table in
subsequent units of work are logged (journaled).
The NOT LOGGED INITIALLY option is useful for situations where a large
result set needs to be created with data from an alternate source (another
table or a file) and recovery of the table is not necessary. Using this option
will save the overhead of logging (journaling) the data.
ACTIVATE NOT LOGGED INITIALLY is ignored if the table has a
DATALINK column with FILE LINK CONTROL.
Indicates to the optimizer whether or not the cardinality of table table-name can vary significantly at run time. Volatility applies to
the number of rows in the table, not to the table itself. The default is NOT
VOLATILE.
- VOLATILE
- Specifies that the cardinality of table-name can vary significantly
at run time, from empty to large. To access the table, the optimizer will
typically use an index, if possible.
- NOT VOLATILE
- Specifies that the cardinality of table-name is not volatile.
Access plans that reference this table will be based on the cardinality of
the table at the time the access plan is built. NOT VOLATILE is the default.
- IN nodegroup-name
- Specifies the nodegroup across which the data in the table will be distributed.
The name must identify a nodegroup that exists at the current server. If this
clause is specified, the table is created as a distributed table across all
the systems in the nodegroup.
A LOB, DATALINK, or IDENTITY column
is not allowed in a distributed table.
The DB2 Multisystem product must be
installed to create a distributed table. For more information about distributed
tables, see the DB2® Multisystem book.
- DISTRIBUTE BY HASH (column-name,...)
- Specifies the partitioning key. The partitioning key is used to determine
on which node in the nodegroup a row will be placed. Each column-name must be an unqualified name that identifies a column of the table. The
same column must not be identified more than once. If the DISTRIBUTE BY clause
is not specified, the first column of the primary key is used as the partitioning
key. If there is no primary key, the first column of the table that is not
floating point, date, time, or timestamp is used as the partitioning key.
The columns that make up the partitioning key must be a subset of the columns
that make up any unique constraints over the table. Floating point, LOB, DataLink,
and ROWID columns cannot be used in a partitioning key.
- PARTITION BY RANGE
- Specifies that ranges of column values are used to determine
the target data partition when inserting a row into the table. The number
of partitions must not exceed 256. A table cannot be partitioned
if it contains an identity column.
- column-name
- Specifies a column in the partitioning key. The partitioning key is
used to determine into which partition in the table a row will be placed.
Each column-name must be an unqualified name that identifies a column
of the table. The same column must not be identified more than once.
Floating
point, LOB, DataLink, and ROWID columns cannot be used in a partitioning key.
- NULLS LAST
- Indicates that null values are treated as positive infinity for comparison
purposes.
- NULLS FIRST
- Indicates that null values are treated as negative infinity for comparison
purposes.
- PARTITION partition-name
- Names the partition. A partition-name must not identify a data
partition that was previously specified in the CREATE TABLE statement.
If the clause is not specified, a unique partition name is generated by the
database manager.
- boundary-spec
- Specifies the boundaries of a range partition. The boundaries must be
specified in ascending sequence. The ranges must not overlap.
- starting-clause
- Specifies the low end of the range for a data partition. The number
of specified starting values must be the same as the number of columns in
the partitioning key.
- STARTING FROM
- Introduces the starting-clause.
- constant
- Specifies a constant that must conform to the rules of a constant for
the data type of the corresponding column of the partition key. If the corresponding
column of the partition key is a distinct type, the constant must conform
to the rules of the source type of the distinct type. The value must not be
in the range of any other boundary-spec for the table.
- MINVALUE
- Specifies a value lower than the lowest possible value for
the data type of the corresponding column of the partition key. If MINVALUE
is specified, all subsequent values in the starting-clause must also
be MINVALUE.
- INCLUSIVE
- Specifies that the specified range values are included in the data partition.
- EXCLUSIVE
- Specifies that the specified range values are excluded from the data
partition. This specification is ignored when MINVALUE or MAXVALUE is specified.
- ending-clause
- Specifies the high end of the range for a data partition. The number
of specified ending values must be the same as the number of columns in the
data partitioning key.
- ENDING AT
- Introduces the ending-clause.
- constant
- Specifies a constant that must conform to the rules of a constant for
the data type of the corresponding column of the partition key. If the corresponding
column of the partition key is a distinct type, the constant must conform
to the rules of the source type of the distinct type. The value must not be
in the range of any other boundary-spec for the table.
- MAXVALUE
- Specifies a value higher than the highest possible value
for the data type of the corresponding column of the partition key. If MAXVALUE
is specified, all subsequent values in the ending-clause must also
be MAXVALUE.
- INCLUSIVE
- Specifies that the specified range values are included in the data partition.
- EXCLUSIVE
- Specifies that the specified range values are excluded from the data
partition. This specification is ignored when MINVALUE or MAXVALUE is specified.
- EVERY integer-constant
- Specifies that multiple data partitions will be added where integer-constant specifies the width of each data partition range. If EVERY is specified,
only a single SMALLINT, INTEGER, BIGINT, DECIMAL, NUMERIC, DATE, or TIMESTAMP
column can be specified for the partition key.
The starting value of the
first data partition is the specified STARTING value. The starting value of
each subsequent partition is the starting value of the previous partition
+ integer-constant. If the starting-clause specified EXCLUSIVE,
the starting value of every partition is EXCLUSIVE. Otherwise, the starting
value of every partition is INCLUSIVE.
The ending value of every partition
of the range is (start + integer-constant - 1). If the ending-clause specified EXCLUSIVE, the ending value of every partition is EXCLUSIVE.
Otherwise, the ending value of every partition is INCLUSIVE.
The number
of partitions added is determined by adding integer-constant repeatedly
to the STARTING value until the ENDING value is reached. For example:
CREATE TABLE FOO
(A INT)
PARTITION BY RANGE(A)
(STARTING(1) ENDING(10) EVERY(2))is equivalent to
the following CREATE TABLE statement:
CREATE TABLE FOO
(A INT)
(PARTITION BY RANGE(A)
(STARTING(1) ENDING(2),
STARTING(3) ENDING(4),
STARTING(5) ENDING(6),
STARTING(7) ENDING(8),
STARTING(9) ENDING(10))
In the case of dates and timestamps, the
EVERY value must be a labeled duration. For example:
CREATE TABLE FOO
(A DATE)
PARTITION BY RANGE(A)
(STARTING('2001-01-01') ENDING('2010-01-01') EVERY(3 MONTHS))
- PARTITION BY HASH
- Specifies that the hash function is used to determine the target data
partition when inserting a row into the table. A table cannot
be partitioned if it contains an identity column.
- (column-name,...)
- Specifies the partitioning key. The partitioning key is used to determine
into which partition in the table a row will be placed. Each column-name must be an unqualified name that identifies a column of the table. The
same column must not be identified more than once.
The columns that make
up the partitioning key must be a subset of the columns that make up any unique
constraints over the table. Floating point, LOB, date, time, timestamp, DataLink,
and ROWID columns cannot be used in a partitioning key.
- INTO integer PARTITIONS
- Specifies the number of partitions. The number of partitions must not
exceed 256.
Table attributes: Tables are created as physical
files. When a table is created, the file wait time and record wait time attributes
are set to the default that is specified on the WAITFILE and WAITRCD keywords
of the Create Physical File (CRTLF) command.
SQL tables are created so that space used by deleted rows will be reclaimed
by future insert requests. This attribute can be changed via the command CHGPF and specifying the REUSEDLT(*NO) parameter. For more information
about the CHGPF command, see the CL Reference information in the Programming category of the iSeries Information Center.
A distributed table is created on all of the servers across which the table
is distributed. For more information about distributed tables, see the DB2 Multisystem book.
Table journaling: When a table is created, journaling
may be automatically started.
- If a data area called QDFTJRN exists in the same schema that the table
is created into and the user is authorized to the data area, journaling will
be started to the journal named in the data area if all the following are
true:
- The identified schema for the table must not be QSYS, QSYS2,
QRECOVERY, QSPL, QRCL, QRPLOBJ, QGPL, QTEMP, SYSIBM, or any of the iASP equivalents
to these libraries.
- The journal specified in the data area must exist and the user must be
authorized to start journaling to the journal.
- The first 10 bytes of the data area must contain the name of the schema
in which to find the journal.
- The second 10 bytes must contain the name of the journal.
- The remaining bytes contain the object types being implicitly
journaled and the options that affect when implicit journaling is performed.
The object type must include the value *FILE or *ALL. The value *NONE can
be used to prevent journaling from being started.
For more information, see the Journal Management topic in the iSeries™ Information Center.
- If a data area called QDFTJRN does not exist in the same schema that the
table is created into or the user is not authorized to the data area, journaling
will be started to a journal called QSQJRN if it exists in the same schema
that the table is created into.
Table ownership: If SQL names were specified:
- If a user profile with the same name as the schema into which the table
is created exists, the owner of the table is that
user profile.
- Otherwise, the owner of the table is the user
profile or group user profile of the job executing the statement.
If system names were specified, the owner of the
table is the user profile or group user profile of the job executing the statement.
Table authority: If SQL names are used, tables are
created with the system authority of *EXCLUDE to *PUBLIC. If system names
are used, tables are created with the authority to *PUBLIC as determined by
the create authority (CRTAUT) parameter of the schema.
If the owner of the table is a member of a group profile (GRPPRF keyword)
and group authority is specified (GRPAUT keyword), that group profile will
also have authority to the table.
Owner privileges: The owner of the table
has all table privileges (see GRANT (Table or View Privileges)) with the ability to grant
these privileges to others.
Using an identity column: When a table
has an identity column, the database manager can automatically generate sequential
numeric values for the column as rows are inserted into the table. Thus, identity
columns are ideal for primary keys.
Identity columns and ROWID columns are similar in that both types of columns
contain values that the database manager generates. ROWID columns can be useful in direct-row
access. ROWID columns contain values of the ROWID data type, which returns
a 40-byte VARCHAR value that is not regularly ascending or descending. ROWID
data values are therefore not well suited to many application uses, such as
generating employee numbers or product numbers. For data that does not require
direct-row access, identity columns are usually a better approach, because
identity columns contain existing numeric data types and can be used in a
wide variety of uses for which ROWID values would not be suitable.
When a table is recovered to a point-in-time (using RMVJRNCHG), it is possible
that a large gap in the sequence of generated values for the identity column
might result. For example, assume a table has an identity column that has
an incremental value of 1 and that the last generated value at time T1 was
100 and the database manager subsequently generates values up to 1000. Now, assume that
the table is recovered back to time T1. The generated value of the identity
column for the next row that is inserted after the recovery completes will
be 1001, leaving a gap from 100 to 1001 in the values of the identity column.
When CYCLE is specified duplicate values for a column may be generated
even when the column is GENERATED ALWAYS, unless a unique constraint or unique
index is defined on the column.
Creating materialized query tables: To
ensure that the materialized query table has data before being used by a query:
- DATA INITIALLY IMMEDIATE should be used to create materialized query tables,
or
- the materialized query table should be created with query optimization
disabled and then enable the table for query optimization after it is refreshed.
The isolation level at the time when the CREATE TABLE statement is executed
is the isolation level for the materialized query table. The isolation-clause can be used to explicitly specify the isolation level.
Partitioned table performance: The larger the number
of partitions in a partitioned table, the greater the overhead in SQL data
change and SQL data statements. You should create a partitioned table with
the minimum number of partitions that are required to minimize this overhead.
It is also highly recommended that a parallelism degree greater than one be
considered when accessing a partitioned table.
Syntax alternatives: The following keywords are synonyms
supported for compatibility to prior releases. These keywords are non-standard
and should not be used:
Maximum row sizes
There are two maximum row size restrictions referred to in the description
of column-definition.
- The maximum row buffer size is 32766 or, if a VARCHAR, VARGRAPHIC, or
LOB column is specified, 32740.
- The maximum row data size is 3 758 096 383, if a LOB is specified. If
a LOB is not specified, then the maximum row data size is 32766 or, if a VARCHAR
or VARGRAPHIC column is specified, 32740.
To determine the length of a row buffer and/or row data add the corresponding
length of each column of that row based on the byte counts of the data type.
The follow table gives the byte counts of columns by data type for columns
that do not allow null values. If any column allows null values, one byte
is required for every eight columns.
Table 52. Byte Counts of Columns by Data Type
| Data Type |
Row Buffer Byte Count |
Row Data Byte Count |
| SMALLINT |
2 |
2 |
| INTEGER |
4 |
4 |
| BIGINT |
8 |
8 |
| DECIMAL( p, s) |
The integral part of (p/2) + 1 |
The integral part of (p/2) + 1 |
| NUMERIC( p, s) |
p |
p |
| FLOAT (single precision) |
4 |
4 |
| FLOAT (double precision) |
8 |
8 |
| CHAR( n) |
n |
n |
| VARCHAR( n) |
n+2 |
n+2 |
| CLOB( n) |
29+pad |
n+29 |
| GRAPHIC(n) |
n*2 |
n*2 |
| VARGRAPHIC (n) |
n*2+2 |
n*2+2 |
| DBCLOB( n) |
29+pad |
n*2+29 |
| BINARY( n) |
n |
n |
| VARBINARY( n) |
n+2 |
n+2 |
| BLOB( n) |
29+pad |
n+29 |
| DATE |
10 |
4 |
| TIME |
8 |
3 |
| TIMESTAMP |
26 |
10 |
| DATALINK( n) |
n+24 |
n+24 |
| ROWID |
42 |
28 |
| distinct-type |
The byte count for the source type. |
The byte count for the source type. |
|
Notes:
pad is a value from 1 to 15 necessary
for boundary alignment. |
Precision as described to the database:
- Floating-point fields are defined in the iSeries database with a decimal
precision, not a bit precision. The algorithm used to convert the number of
bits to decimal is decimal precision = CEILING(n/3.31),
where n is the number of bits to convert. The decimal precision is
used to determine how many digits to display using interactive SQL.
- SMALLINT fields are stored with a decimal precision of 4,0.
- INTEGER fields are stored with a decimal precision of 9,0.
- BIGINT fields are stored with a decimal precision of 19,0.
LONG VARCHAR and LONG VARGRAPHIC
The non-standard syntax of LONG VARCHAR and LONG VARGRAPHIC is supported,
but deprecated. The alternative standard syntax of VARCHAR(integer) and VARGRAPHIC(integer),
is preferred. VARCHAR(integer) and VARGRAPHIC(integer) are recommended. After
the CREATE TABLE statement is processed, the database manager considers a
LONG VARCHAR column to be VARCHAR and a LONG VARGRAPHIC column to be VARGRAPHIC.
The maximum length is calculated in a product-specific fashion that is not
portable.
- LONG VARCHAR 68
- For a varying length character string whose maximum length is determined
by the amount of space available in the row.
- LONG VARGRAPHIC 68
- For a varying length graphic string whose maximum length is determined
by the amount of space available in the row.
The maximum length of a LONG column is determined as follows. Let:
- i be the sum of the row buffer byte counts of all columns in
the table that are not LONG VARCHAR or LONG VARGRAPHIC
- j be the number of LONG VARCHAR and LONG VARGRAPHIC columns
in the table
- k be the number of columns in the row that allow nulls.
The length of each LONG VARCHAR column is INTEGER((32716 - i-((k+7)/8))/j).
The length of each LONG VARGRAPHIC column is determined by taking the length
calculated for a LONG VARCHAR column and dividing it by 2. The integer portion
of the result is the length.
There are specific instances when the system generates a system table,
view, index, or column name. These instances and the name generation rules
are described in the following sections.
Rules for Column Name Generation
A system-column-name is generated if the system-column-name is not specified
when a table or view is created and the column-name is not a valid system-column-name.
If the column-name does not contain special characters and is longer than
10 characters, a 10-character system-column-name will be generated as:
- The first 5 characters of the name
- A 5 digit unique number
For example:
The system-column-name for LONGCOLUMNNAME would be LONGC00001
If the column name is delimited:
- The first 5 characters from within the delimiters will be used as the
first 5 characters of the system-column-name. If there are fewer than 5 characters
within the delimiters, the name will be padded on the right with underscore
(_) characters. Lower case characters are folded to upper case characters.
The only valid characters in a system-column-name are: A-Z, 0-9, @, #, $,
and _. Any other characters will be changed to the underscore (_) character.
If the first character ends up as an underscore, it will be changed to the
letter Q.
- A 5 digit unique number is appended to the 5 characters.
For example:
The system-column-name for "abc" would be ABC__00001
The system-column-name for "COL2.NAME" would be COL2_00001
The system-column-name for "C 3" would be C_3__00001
The system-column-name for "??" would be Q____00001
The system-column-name for "*column1" would be QCOLU00001
Rules for Table Name Generation
A system name will be generated if a table, view, alias, or index is created
with either:
- A name longer than 10 characters
- A name that contains characters not valid in a system name
The SQL name or its corresponding system name may both be used in SQL
statements to access the file once it is created. However, the SQL name is
only recognized by DB2 UDB for iSeries and the system name must be used in other environments.
If the name does not contain special characters and is longer than 10 characters,
a 10-character system name will be generated as:
- The first 5 characters of the name
- A 5 digit unique number
For example:
The system name for LONGTABLENAME would be LONGT00001
If the SQL name contains special characters, the system name is generated
as:
- The first 4 characters of the name
- A 4 digit unique number
In addition:
- All special characters are replaced by the underscore (_)
- Any trailing blanks are removed from the name
- The name is delimited by double quotes (") if the delimiters are required
for the name to be a valid system name.
For example:
The system name for "??" would be "__0001"
The system name for "longtablename" would be "long0001"
The system name for "LONGTableName" would be LONG0001
The system name for "A b " would be "A_b0001"
SQL ensures the system name is unique by searching the cross reference
file. If the name already exists in the cross reference file, the number is
incremented until the name is no longer a duplicate.
If a unique name cannot be determined using the above rules, an additional
character is added to the counter in the name, and the number is incremented
until a unique name can be found or the range is exhausted. For example, if
creating "longtablename" and names "long0001" through "long9999" already exist,
the name would become "lon00001".
Example 1: Given administrative authority, create
a table named 'ROSSITER.INVENTORY' with the following columns:
- Part number
- Small integer, must not be null
- Description
- Character of length 0 to 24, allows nulls
- Quantity on hand,
- Integer allows nulls
CREATE TABLE ROSSITER.INVENTORY
(PARTNO SMALLINT NOT NULL,
DESCR VARCHAR(24),
QONHAND INT)
Example 2: Create a table named DEPARTMENT with
the following columns:
- Department number
- Character of length 3, must not be null
- Department name
- Character of length 0 through 36, must not be null
- Manager number
- Character of length 6
- Administrative dept.
- Character of length 3, must not be null
- Location name
- Character of length 16, allows nulls
The primary key is column DEPTNO.
CREATE TABLE DEPARTMENT
(DEPTNO CHAR(3) NOT NULL,
DEPTNAME VARCHAR(36) NOT NULL,
MGRNO CHAR(6),
ADMRDEPT CHAR(3) NOT NULL,
LOCATION CHAR(16),
PRIMARY KEY(DEPTNO))
Example 3: Create a table named REORG_PROJECTS
which has the same column definitions as the columns in the view PRJ_LEADER.
CREATE TABLE REORG_PROJECTS
LIKE PRJ_LEADER
Example 4: Create an EMPLOYEE2 table with an identity
column named EMP_NO. Define the identity column so that DB2 will always
generate the values for the column. Use the default value, which is 1, for
the first value that should be assigned and for the incremental difference
between the subsequently generated consecutive numbers.
CREATE TABLE EMPLOYEE2
( EMPNO INTEGER GENERATED ALWAYS AS IDENTITY,
ID SMALLINT,
NAME CHAR(30),
SALARY DECIMAL(5,2),
DEPTNO SMALLINT)
Example 5: Assume a very large transaction table
named TRANS contains one row for each transaction processed by a company.
The table is defined with many columns. Create a materialized query table
for the TRANS table that contains daily summary data for the date and amount
of a transaction.
CREATE TABLE STRANS
AS (SELECT YEAR AS SYEAR, MONTH AS SMONTH, DAY AS SDAY, SUM(AMOUNT) AS SSUM
FROM TRANS
GROUP BY YEAR, MONTH, DAY )
DATA INITIALLY DEFERRED
REFRESH DEFERRED
MAINTAINED BY USER
This option is provided for compatibility with other
products. It is recommended that VARCHAR(integer) or VARGRAPHIC(integer)
be specified instead.
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