Naming conventions

The rules for forming a name depend on the type of the object designated by the name and the naming option (*SQL or *SYS). The naming option is specified on the CRTSQLxxx, RUNSQLSTM, and STRSQL commands. The SET OPTION statement can be used to specify the naming option within the source of a program containing embedded SQL. The syntax diagrams use different terms for different types of names. The following list defines these terms.

alias-name

A qualified or unqualified name that designates an alias. The qualified form of an alias-name depends on the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and an SQL identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by an SQL identifier.

The unqualified form of an alias-name is an SQL identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

An alias-name can specify either the name of the alias or the system object name of the alias.

authorization-name

A system identifier that designates a user or group of users. An authorization-name is a user profile name on the server. It must not be a delimited identifier that includes lowercase letters or special characters. See Authorization IDs and authorization names for the distinction between an authorization-name and an authorization ID.

column-name

A qualified or unqualified name that designates a column of a table or a view. The unqualified form of a column-name is an SQL identifier. The qualified form is a qualifier followed by a period and an SQL identifier. The qualifier is a table name, a view name, or a correlation name.

Column names cannot be qualified with system names in the form schema-name/table-name.column-name, except in the COMMENT and LABEL statements. If column names need to be qualified, and correlation names are allowed in the statement, a correlation name must be used to qualify the column.

A column-name can specify either the column name or the system column name of a column of a table or view. If a column-name is delimited, the delimiters are considered to be part of the name when determining the length of the name.

constraint-name

A qualified or unqualified name that designates a constraint on a table. The qualified form of a constraint-name depends on the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and a system identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by an SQL identifier.

The unqualified form of a constraint-name is an SQL identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

correlation-name

An SQL identifier that designates a table, a view, or individual rows of a table or view.

cursor-name

An SQL identifier that designates an SQL cursor.

descriptor-name

A variable name or string constant that designates an SQL descriptor area (SQLDA). A variable that designates an SQL descriptor area must not have an indicator variable. The form :host-variable:indicator-variable is not allowed. See References to host variables for a description of a variable.

distinct-type-name

A qualified or unqualified name that designates a distinct type. The qualified form of a distinct-type-name depends upon the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and an SQL identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by an SQL identifier.

The unqualified form of a distinct-type-name is an SQL identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

For system naming, distinct-type-names cannot be qualified when used in a parameter data type of an SQL routine or in an SQL variable declaration in an SQL function, SQL procedure, or trigger.

external-program-name

A qualified name, unqualified name, or a character string that designates an external program. The qualified form of an external-program-name depends on the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and a system identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by a system identifier.

The unqualified form of an external-program-name is a system identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

The format of the character string form is either:

An i5/OS qualified program name ('library-name/program-name').
An i5/OS qualified source file name, followed by a left parenthesis, followed by an i5/OS member name, and a right parenthesis ('library-name/source-file-name(member-name)'). This form is only valid when calling a REXX procedure.
An i5/OS qualified service program name, followed by a left parenthesis, followed by an i5/OS entry-point-name, followed by a right parenthesis ('library-name/service-program-name(entry-point-name)').
In Java™, an optional jar-name, followed by a class identifier, followed by an exclamation point or period, followed by a method identifier ('class-id!method-id' or 'class-id.method-id').
```
>>-+-------------+--class-id--+-!-+--method-id-----------------><
   '-jar-name--:-'            '-.-'
 
```
jar-name

The jar-name is a case-sensitive string that identifies the jar schema when it was installed in the database. It can be either a simple identifier, or a schema qualified identifier. Examples are 'myJar' and 'myCollection.myJar'.

class-id
The class-id identifies the class identifier of the Java object. If the class is part of a Java package, the class identifier must include the complete Java package prefix. For example, if the class identifier is 'myPackage.StoredProcs', the Java virtual machine will look in the following directory for the StoredProcs class:
```
   '/QIBM/UserData/OS400/SQLLib/
     Function/myPackage/StoredProcs/'
```
method-id

The method-id identifies the method name of the public, static Java method to be invoked.
This form is only valid for Java procedures and Java functions.

function-name

A qualified or unqualified name that designates a user-defined function, a cast function that was generated when a distinct type was created, or a built-in function. The qualified form of a function-name depends upon the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and an SQL identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by an SQL identifier.

The unqualified form of a function-name is an SQL identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

For system naming, functions names can only be qualified in the form schema-name/function-name when the name is used in a CREATE, COMMENT, DROP, GRANT, or REVOKE statement.

host-label

A token that designates a label in a host program.

host-variable

A sequence of tokens that designates a host variable. A host-variable includes at least one host-identifier, as explained in References to host variables.

index-name

A qualified or unqualified name that designates an index. The qualified form of an index-name depends upon the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and an SQL identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by an SQL identifier.

The unqualified form of an index-name is an SQL identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

nodegroup-name

A qualified or unqualified name that designates a nodegroup. A nodegroup is a group of iSeries servers across which a table will be distributed. For more information about distributed tables and nodegroups, see the DB2® Multisystem book.

The qualified form of a nodegroup-name depends on the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and a system identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by a system identifier.

The unqualified form of a nodegroup-name is a system identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

package-name

A qualified or unqualified name that designates a package. The qualified form of a package-name depends upon the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and a system identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by a system identifier.

The unqualified form of a package-name is a system identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

parameter-name

An SQL identifier that designates a parameter for a function or procedure. If the parameter-name is for a procedure, the identifier may be preceded by a colon.

partition-name

An unqualified identifier that designates a partition of a partitioned table.

procedure-name

A qualified or unqualified name that designates a procedure. The qualified form of a procedure-name depends upon the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and an SQL identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by an SQL identifier.

The unqualified form of a procedure-name is an SQL identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

savepoint-name

An unqualified identifier that designates a savepoint.

schema-name

A qualified or unqualified name that provides a logical grouping for SQL objects. A schema name is used as a qualifier of the name of a table, view, index, procedure, function, trigger, constraint, alias, type, or package. The unqualified form of a schema-name is a system identifier. The qualified form of a schema-name depends on the naming option.

For SQL names, the unqualified schema name in an SQL statement is implicitly qualified by the server-name. The qualified form is a server-name followed by a (.) and a system identifier. The server-name must identify the current server.

For system names, the unqualified schema name in an SQL statement is implicitly qualified by the server-name. The qualified form is a server-name followed by a slash (/) and a system identifier. The server-name must identify the current server.

Note:

schema-name refers to either a schema created by the CREATE SCHEMA statement or to an i5/OS library.

sequence-name

A qualified or unqualified name that designates a sequence. The qualified form of a sequence-name depends upon the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and an SQL identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by an SQL identifier. For system naming, a sequence-name cannot be qualified when used in a NEXT VALUE or PREVIOUS VALUE expression (the qualified form is only allowed in SQL schema statements).

The unqualified form of a sequence-name is an SQL identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

A sequence-name can specify either the name of the sequence or the system object name of the sequence.

server-name

An SQL identifier that designates an application server. The identifier must start with a letter and must not include lowercase letters or special characters.

specific-name

A qualified or unqualified name that uniquely identifies a procedure or function. The qualified form of a specific-name depends upon the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and an SQL identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by an SQL identifier.

The unqualified form of a specific-name is an SQL identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

SQL-descriptor-name

A variable name or character or graphic string constant that designates an SQL descriptor that was allocated using the ALLOCATE DESCRIPTOR statement.

If a variable is used to designate the SQL descriptor:

The variable must not be a CLOB or DBCLOB.
If the variable is a graphic string, it must be a UTF-16 or UCS-2 graphic string.
The length of the contents of the variable must not exceed the maximum length for an SQL-descriptor-name.
An indicator variable must not be specified. The form :host-variable:indicator-variable is not allowed.
The contents of the variable are case-sensitive and are not converted to uppercase.

Leading and trailing blanks are trimmed from the variable or string. See References to host variables for a description of a variable.

If a string constant is used to designate the SQL descriptor, the length of the constant must not exceed the maximum length for an SQL-descriptor-name.

SQL-label

An unqualified name that designates a label in an SQL procedure, SQL function, or trigger body. An SQL-label is an SQL identifier.

SQL-parameter-name

A qualified or unqualified name that designates a parameter in an SQL routine body. The unqualified form of an SQL-parameter-name is an SQL identifier. The qualified form is a procedure-name followed by a period (.) and an SQL identifier.

SQL-variable-name

A qualified or unqualified name that designates a variable in an SQL routine body. The unqualified form of an SQL-variable-name is an SQL identifier. The qualified form is an SQL-label followed by a period (.) and an SQL identifier.

statement-name

An SQL identifier that designates a prepared SQL statement.

system-column-name

An unqualified name that designates the i5/OS column name of a table or a view. A system-column-name is a system identifier. System-column-names can be delimited identifiers, but the characters within the delimiters must not include lowercase letters or special characters.

system-object-name

An unqualified name that designates the i5/OS name of a table, view, index, sequence, or alias. A system-object-name is a system identifier.

If the unqualified name of the table, view, index, sequence, or alias is a valid system identifier, the system-object-name of the table, view, index, sequence, or alias is the unqualified name of the table, view, index, sequence, or alias.

table-name

A qualified or unqualified name that designates a table. The qualified form of a table-name depends upon the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and an SQL identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by an SQL identifier.

The unqualified form of a table-name is an SQL identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

A table-name can specify either the name of the table or the system object name of the table.

trigger-name

A qualified or unqualified name that designates a trigger on a table. The qualified form of a trigger-name depends on the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and a system identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by an SQL identifier.

The unqualified form of a trigger-name is an SQL identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

version-id

An identifier of 1 to 64 characters that is assigned to a package when the package is created. A version-id is only assigned when packages are created from a server other than DB2 UDB for iSeries.

view-name

A qualified or unqualified name that designates a view. The qualified form of a view-name depends upon the naming option. For SQL naming, the qualified form is a schema-name followed by a period (.) and an SQL identifier. For system naming, the qualified form is a schema-name followed by a slash (/) followed by an SQL identifier.

The unqualified form of a view-name is an SQL identifier. The unqualified form is implicitly qualified based on the rules specified in Qualification of unqualified object names.

A view-name can specify either the name of the view or the system object name of the view.

Table 2. Identifier Length Limits (in bytes)
Identifier Type	Maximum Length
Longest authorization name¹⁷	10
Longest condition name	128
Longest correlation name	128
Longest cursor name	18
Longest external program name (unqualified form)¹⁸	10
Longest external program name (string form)	279
Longest host identifier	64
Longest partition name	10
Longest savepoint name	128
Longest schema name	10
Longest server name	18
Longest SQL-descriptor-name	128
Longest SQL label	128
Longest statement name	18
Longest unqualified alias name	128
Longest unqualified column name	128
Longest unqualified constraint name	128
Longest unqualified distinct type name	128
Longest unqualified function name	128
Longest unqualified index name	128
Longest unqualified nodegroup name	10
Longest unqualified package name	10
Longest package version-id	64
Longest unqualified parameter name	128
Longest unqualified procedure name	128
Longest unqualified sequence name	128
Longest unqualified specific name	128
Longest unqualified SQL parameter name	128
Longest unqualified SQL variable name	128
Longest unqualified system column name	10
Longest unqualified system object name	10
Longest unqualified table and view name	128
Longest unqualified trigger name	128

SQL path

The SQL path is an ordered list of schema names. The database manager uses the path to resolve the schema name for unqualified distinct type names (both built-in types and distinct types), function names, and procedure names that appear in any context other than as the main object of a CREATE, DROP, COMMENT, GRANT or REVOKE statement. Searching through the path from left to right, the database manager implicitly qualifies the object name with the first schema name in the path that contains the same object with the same unqualified name. For procedures, the database manager selects a matching procedure name only if the number of parameters is also the same. For functions, the database manager uses a process called function resolution in conjunction with the SQL path to determine which function to choose because several functions with the same name can reside in a schema. (For details, see Function resolution.)

For example, if the SQL path is SMITH, XGRAPHIC, QSYS, QSYS2 and an unqualified distinct type name MYTYPE was specified, the database manager looks for MYTYPE first in schema SMITH, then XGRAPHIC, and then QSYS and QSYS2.

The path used is determined as follows:

For all static SQL statements (except for a CALL variable statement), the path used is the value of the SQLPATH parameter on the CRTSQLxxx command. The SQLPATH can also be set using the SET OPTION statement.
For dynamic SQL statements (and for a CALL variable statement), the path used is the value of the CURRENT PATH special register. For more information about the CURRENT PATH special register, see CURRENT PATH.

If the SQL path is not explicitly specified, the SQL path is the system path followed by the authorization ID of the statement.

For more information on the SQL path for dynamic SQL, see CURRENT PATH.

Qualification of unqualified object names

Unqualified object names are implicitly qualified. The rules for qualifying a name differ depending on the type of object that the name identifies.

Unqualified alias, constraint, external program, index, nodegroup, package, sequence, table, trigger, and view names

Unqualified alias, constraint, external program, index, nodegroup, package, sequence, table, trigger, and view names are implicitly qualified by the default schema. The default schema is specified as follows:

For static SQL statements:
- If the DFTRDBCOL parameter is specified on the CRTSQLxxx command (or with the SET OPTION statement), the default schema is the schema-name that is specified for that parameter.
- In all other cases, the default schema is based on the naming convention.
  - For SQL naming, the default schema is the authorization identifier of the statement.
  - For system naming, the default schema is the job library list (*LIBL).

For dynamic SQL statements the default schema depends on whether or not a default schema has been explicitly specified. The mechanism for explicitly specifying this depends on the interface used to dynamically prepare and execute SQL statements.

If a default schema is not explicitly specified:
- For SQL naming, the default schema is the run-time authorization identifier.
- For system naming, the default schema is the job library list (*LIBL).

The default schema is explicitly specified through the following interfaces:

Table 3. Default Schema Interfaces
SQL Interface	Specification
Embedded SQL	DFTRDBCOL parameter and DYNDFTCOL(*YES) on the Create SQL Program (CRTSQLxxx) and Create SQL Package (CRTSQLPKG) commands. The SET OPTION statement can also be used to set the DFTRDBCOL and DYNDFTCOL values. (For more information about CRTSQLxxx commands, see the Embedded SQL Programming book.)
Run SQL Statements	DFTRDBCOL parameter on the Run SQL Statements (RUNSQLSTM) command. (For more information about the RUNSQLSTM command, see the SQL Programming book.)
Call Level Interface (CLI) on the server	SQL_ATTR_DEFAULT_LIB or SQL_ATTR_DBC_DEFAULT_LIB environment or connection variables (For more information about CLI, see the SQL Call Level Interfaces (ODBC) book.)
JDBC or SQLJ on the server using IBM® Developer Kit for Java	libraries property object (For more information about JDBC and SQLJ, see the IBM Developer Kit for Java topic in the iSeries Information Center.)
ODBC on a client using the iSeries Access Family ODBC Driver	SQL Default Library in ODBC Setup (For more information about ODBC, see the iSeries Access category in the iSeries Information Center.)
JDBC on a client using the IBM Toolbox for Java	SQL Default Library in JDBC Setup (For more information about JDBC, see the iSeries Access category in the iSeries Information Center.) (For more information about the IBM Toolbox for Java, see IBM Toolbox for Java topic in the iSeries Information Center.)
OLE DB on a client using the iSeries Access Family OLE DB Provider	Default Collection in Connection Object Properties (For more information about ODBC, see the iSeries Access category in the iSeries Information Center.)
All interfaces	SET SCHEMA or QSQCHGDC (Change Dynamic Default Collection) API (For more information about QSQCHGDC, see the File APIs category in the iSeries Information Center.)

Unqualified function, procedure, specific, and distinct type names

The qualification of data type (both built-in types and distinct types), function, procedure, and specific names depends on the SQL statement in which the unqualified name appears:

If an unqualified name is the main object of a CREATE, COMMENT, DROP, GRANT, or REVOKE statement, the name is implicitly qualified using the same rules as for qualifying unqualified table names (See Unqualified alias, constraint, external program, index, nodegroup, package, sequence, table, trigger, and view names).
Otherwise, the implicit schema name is determined as follows:
- For distinct type names, the database manager searches the SQL path and selects the first schema in the path such that the data type exists in the schema.
- For procedure names, the database manager searches the SQL path and selects the first schema in the path such that the schema contains a procedure with the same name and number of parameters.
- For function names and for specific names specified for sourced functions, the database manager uses the SQL path in conjunction with function resolution, as described under Function resolution.

SQL names and system names: special considerations

The CL command Override Database File (OVRDBF) can be specified to override an SQL or system name with another object name for local data manipulation SQL statements. Overrides are ignored for data definition SQL statements and data manipulation SQL statements executing at a remote relational database. See the File Management book for more information about the override function.

17.

As an application requester, iSeries™ can send an authorization name of up to 255 bytes.

18.

For REXX procedures, the limit is 33.

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