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<h1 class="topictitle1">SQLDA format</h1>
<div><p>The SQLDA consists of four variables followed by an arbitrary number
of occurrences of a sequence of six variables collectively named SQLVAR.</p>
<div class="section"><div class="note"><span class="notetitle">Note:</span> The SQLDA in REXX is different. </div>
<p>When an SQLDA is used in OPEN, FETCH, CALL, and EXECUTE, each occurrence
of SQLVAR describes a host variable.</p>
</div>
<div class="section"><p>The fields of the SQLDA are as follows:</p>
<dl><dt class="dlterm">SQLDAID</dt>
<dd>SQLDAID is as used an 'eyecatcher" for storage dumps. It is a string of
8 characters that have the value <samp class="codeph">'</samp>SQLDA<samp class="codeph">'</samp> after
the SQLDA is used in a PREPARE or DESCRIBE statement. This variable is not
used for FETCH, OPEN, CALL, or EXECUTE. <p>Byte 7 can be used to determine
if more than one SQLVAR entry is needed for each column. Multiple SQLVAR entries
may be needed if there are any LOB or distinct type columns. This flag is
set to a blank if there are not any LOBs or distinct types.</p>
<p>SQLDAID
is not applicable in REXX.</p>
</dd>
<dt class="dlterm">SQLDABC</dt>
<dd>SQLDABC indicates the length of the SQLDA. It is a 4-byte integer that
has the value SQLN*LENGTH(SQLVAR) + 16 after the SQLDA is used in a PREPARE
or DESCRIBE statement. SQLDABC must have a value equal to or greater than
SQLN*LENGTH(SQLVAR) + 16 before it is used by FETCH, OPEN, CALL, or EXECUTE.
<p>SQLABC is not applicable in REXX.</p>
</dd>
<dt class="dlterm">SQLN</dt>
<dd>SQLN is a 2-byte integer that specifies the total number of occurrences
of SQLVAR. It must be set before being used by any SQL statement to a value
greater than or equal to 0. <p>SQLN is not applicable in REXX.</p>
</dd>
<dt class="dlterm">SQLD</dt>
<dd>SQLD is a 2-byte integer that specifies the number of occurrences of SQLVAR,
in other words, the number of host variables or columns described by the SQLDA.
This field is set by SQL on a DESCRIBE or PREPARE statement. In other statements,
this field must be set before being used to a value greater than or equal
to 0 and less than or equal to SQLN.</dd>
<dt class="dlterm">SQLVAR</dt>
<dd>This group of values are repeated once for each host variable or column.
These variables are set by SQL on a DESCRIBE or PREPARE statement. In other
statements, they must be set before being used. These variables are defined
as follows: <dl><dt class="dlterm">SQLTYPE</dt>
<dd>SQLTYPE is a 2-byte integer that specifies the data type
of the host variable or column. See <a href="../db2/rbafzmstsqltc.htm#sqltc">SQLTYPE
and SQLLEN</a> for a table of the valid values.
Odd values for SQLTYPE show that the host variable has an associated indicator
variable addressed by SQLIND.</dd>
<dt class="dlterm">SQLLEN</dt>
<dd>SQLLEN is a 2-byte integer variable that specifies the length attribute
of the host variable or column.</dd>
<dt class="dlterm">SQLRES</dt>
<dd>SQLRES is a 12-byte reserved area for boundary alignment purposes. Note
that, in <span class="keyword">i5/OS™</span>, pointers <em>must</em> be
on a quad-word boundary. <p>SQLRES is not applicable in REXX.</p>
</dd>
<dt class="dlterm">SQLDATA</dt>
<dd>SQLDATA is a 16-byte pointer variable that specifies the address of the
host variables when the SQLDA is used on OPEN, FETCH, CALL, and EXECUTE. <p>When
the SQLDA is used on PREPARE and DESCRIBE, this area is overlaid with the
following information:</p>
<p>The CCSID of a character or graphic field is
stored in the third and fourth bytes of SQLDATA. For BIT data, the CCSID is
65535. In REXX, the CCSID is returned in the variable SQLCCSID.</p>
</dd>
<dt class="dlterm">SQLIND</dt>
<dd>SQLIND is a 16-byte pointer that specifies the address of a small integer
host variable that is used as an indication of null or not null when the SQLDA
is used on OPEN, FETCH, CALL, and EXECUTE. A negative value indicates null
and a non-negative indicates not null. This pointer is only used if SQLTYPE
contains an odd value. <p>When the SQLDA is used on PREPARE and DESCRIBE,
this area is reserved for future use.</p>
</dd>
<dt class="dlterm">SQLNAME</dt>
<dd>SQLNAME is a variable-length character variable with a maximum length
of 30. After a PREPARE or DESCRIBE, this variable contains the name of selected
column, label, or system column name. In OPEN, FETCH, EXECUTE, or CALL, this
variable can be used to pass the CCSID of character strings. CCSIDs can be
passed for character and graphic host variables. <p>The SQLNAME
field in an SQLVAR array entry of an input SQLDA can be set to specify the
CCSID. See <a href="../db2/rbafzmstsname.htm#sname">CCSID
values in SQLDATA or SQLNAME</a> for the layout of the CCSID data in this
field.</p>
<div class="note"><span class="notetitle">Note:</span> It is important to remember that the SQLNAME field is only
for overriding the CCSID. Applications that use the defaults do not need to
pass CCSID information. If a CCSID is not passed, the default CCSID for the
job is used.</div>
<p>The default for graphic host variables is the associated
double-byte CCSID for the job CCSID. If an associated double-byte CCSID does
not exist, 65535 is used.</p>
</dd>
</dl>
</dd>
</dl>
</div>
<div class="section"> <dl><dt class="dlterm">SQLVAR2</dt>
<dd>This is the Extended SQLVAR structure that contains 3 fields. Extended
SQLVARs are needed for all columns of the result if the result includes any
distinct type or LOB columns. For distinct types, they contain the distinct
type name. For LOBs, they contain the length attribute of the host variable
and a pointer to the buffer that contains the actual length. If locators
are used to represent LOBs, these entries are not necessary. The number of
Extended SQLVAR occurrences needed depends on the statement that the SQLDA
was provided for and the data types of the columns or parameters being described.
Byte 7 of SQLDAID is always set to the number of sets of SQLVARs necessary. <p>If
SQLD is not set to a sufficient number of SQLVAR occurrences: </p>
<ul><li>SQLD is set to the total number of SQLVAR occurrences needed for all sets.</li>
<li>A +237 warning is returned in the SQLCODE field of the SQLCA if at least
enough were specified for the Base SQLVAR Entries. The Base SQLVAR entries
are returned, but no Extended SQLVARs are returned.</li>
<li>A +239 warning is returned in the SQLCODE field of the SQLCA if enough
SQLVARs were not specified for even the Base SQLVAR Entries. No SQLVAR entries
are returned.</li>
</ul>
<dl><dt class="dlterm">SQLLONGLEN</dt>
<dd>SQLLONGLEN is a 4-byte integer variable that specifies the length attribute
of a LOB (BLOB, CLOB, or DBCLOB) host variable or column.</dd>
<dt class="dlterm">SQLDATALEN</dt>
<dd>SQLDATALEN is a 16-byte pointer variable that specifies the address of
the length of the host variable. This variable is used for LOB (BLOB, CLOB,
and DBCLOB) host variables only. It is not used for DESCRIBE or PREPARE. <p>If
this field is NULL, then the actual length of the data is stored in the 4
bytes immediately before the start of the data, and SQLDATA points to the
first byte of the field length. The length indicates the number of bytes for
a BLOB or CLOB, and the number of characters for a DBCLOB.</p>
<p>If this field
is not NULL, it contains a pointer to a 4-byte long buffer that contains the
actual length in bytes (even for DBCLOB) of the data in the buffer pointed
to by the SQLDATA field in the matching base SQLVAR.</p>
</dd>
<dt class="dlterm">SQLDATATYPE_NAME</dt>
<dd>SQLDATATYPE_NAME is a variable-length character variable with a maximum
length of 30. It is only used for DESCRIBE or PREPARE. This variable is set
to one of the following: <ul><li>For a distinct type column, the database manager sets this to the fully
qualified distinct type name. If the qualified name is longer than 30 bytes,
it is truncated.</li>
<li>For a label, the database manager sets this to the first 20 bytes of the
label. </li>
<li>For a column name, the database manager sets this to the column name.</li>
</ul>
</dd>
</dl>
</dd>
</dl>
</div>
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<div>
<div class="familylinks">
<div class="parentlink"><strong>Parent topic:</strong> <a href="rbafyprocesssqlda.htm" title="There are two basic types of SELECT statements: fixed list and varying list.">Process SELECT statements and use a descriptor</a></div>
</div>
<div class="relref"><strong>Related reference</strong><br />
<div><a href="rbafydynexample.htm" title="Suppose your application needs to be able to handle a dynamic SELECT statement, one that changes from one use to the next. This statement can be read from a display, passed in from another application, or built dynamically by your application.">Example: Select-statement for allocating storage for SQLDA</a></div>
</div>
<div class="relinfo"><strong>Related information</strong><br />
<div><a href="../rzajp/rzajprexx.htm">Coding SQL statements in REXX Applications</a></div>
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