125 lines
7.9 KiB
HTML
125 lines
7.9 KiB
HTML
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
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<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-us">
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<meta name="keywords" content="SQL control statements, SQL statements" />
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<title>SQL control statements</title>
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<link rel="stylesheet" type="text/css" href="ibmidwb.css" />
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<body>
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<a id="Top_Of_Page" name="Top_Of_Page"></a><!-- Java sync-link -->
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<script language = "Javascript" src = "../rzahg/synch.js" type="text/javascript"></script>
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<a name="sqlcontstmts"></a>
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<h1 id="sqlcontstmts"><a href="rbafzmst02.htm#ToC_1405">SQL control statements</a></h1><a id="idx3320" name="idx3320"></a><a id="idx3321" name="idx3321"></a>
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<p>Control statements are SQL statements that allow SQL to be used in a manner
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similar to writing a program in a structured programming language. SQL control
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statements provide the capability to control the logic flow, declare and set
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variables, and handle warnings and exceptions. Some SQL control statements
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include other nested SQL statements.</p>
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<a href="rbafzmstsqlcontstmts.htm#syncontrol"><img src="c.gif" alt="Click to skip syntax diagram" /></a>
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<pre class="cgraphic"><span><img src="c.gif" alt="Read syntax diagram" longdesc="rbafzmstsyn404.htm"
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border="0" /></span><a href="#skipsyn-403"><img src="c.gif" alt="Skip visual syntax diagram"
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border="0" /></a>SQL-control-statement:
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|--+-<span class="italic">assignment-statement</span>------+--------------------------------|
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+-<span class="italic">CALL-statement</span>------------+
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+-<span class="italic">CASE-statement</span>------------+
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+-<span class="italic">compound-statement</span>--------+
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+-<span class="italic">FOR-statement</span>-------------+
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+-<span class="italic">GET DIAGNOSTICS-statement</span>-+
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+-<span class="italic">GOTO-statement</span>------------+
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+-<span class="italic">IF-statement</span>--------------+
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+-<span class="italic">ITERATE-statement</span>---------+
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+-<span class="italic">LEAVE-statement</span>-----------+
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+-<span class="italic">LOOP-statement</span>------------+
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+-<span class="italic">REPEAT-statement</span>----------+
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+-<span class="italic">RESIGNAL-statement</span>--------+
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+-<span class="italic">RETURN-statement</span>----------+
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+-<span class="italic">SIGNAL-statement</span>----------+
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'-<span class="italic">WHILE-statement</span>-----------'
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</pre>
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<a name="skipsyn-403" id="skipsyn-403"></a>
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<a name="syncontrol"></a>
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<p id="syncontrol">Control statements are supported in SQL procedures, SQL
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functions, and SQL triggers.</p>
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<p>SQL procedures are created by specifying LANGUAGE SQL and an SQL routine
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body on the CREATE PROCEDURE statement. SQL functions are created by specifying
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LANGUAGE SQL and an SQL routine body on the CREATE FUNCTION statement. SQL
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routines are SQL procedures or SQL functions. SQL triggers are created by
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specifying an SQL routine body on the CREATE TRIGGER statement.</p>
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<p>An SQL routine body must be a single SQL statement which may be an SQL
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control statement.</p>
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<p>The SQL routine body is the executable part of the procedure, function,
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or trigger that is transformed by the database manager into a program or service program.
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When an SQL routine or trigger is created, SQL creates a temporary source
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file (QTEMP/QSQLSRC and QTEMP/QSQLT00000) that will contain C source code
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with embedded SQL statements. If either of these source files exist, they
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will be modified if needed to have the same CCSID as the source. If DBGVIEW(*SOURCE)
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is specified, SQL creates the root source for the routine or trigger in source
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file QSQDSRC in the same library as the procedure, function or trigger.</p>
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<p>An SQL procedure or SQL trigger is created as a program (*PGM) object using
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the CRTPGM command. An SQL function is created as a service program (*SRVPGM)
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object using the CRTSRVPGM command. The program or service program is created
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in the library that is the implicit or explicit qualifier of the procedure,
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function, or trigger name.</p>
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<p>When the program or service program is created, the SQL statements other
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than certain control statements become embedded SQL statements in the program
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or service program. The CALL, SIGNAL, RESIGNAL, and GET DIAGNOSTIC control
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statements also become embedded SQL statements in the program or service program.</p>
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<p>The specified procedure or function is registered in the SYSROUTINES and
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SYSPARMS catalog tables, and an internal link is created from SYSROUTINES
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to the program. When the procedure is called using the SQL CALL statement
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or when the function is invoked in an SQL statement, the program associated
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with the routine is called. The specified SQL trigger is registered in the
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SYSTRIGGER catalog table.</p>
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<p>The remainder of this chapter contains a description of the control statements
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including syntax diagrams, semantic descriptions, usage notes, and examples
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of the use of the statements that constitute the SQL routine body. There is
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also a section on referencing SQL parameters and variables found in <a href="rbafzmstrefsqlv.htm#refsqlv">References to SQL parameters and SQL variables</a>. There are two common elements that are used in describing
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specific SQL control statements. These are:</p>
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<ul>
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<li>SQL control statements as described above</li>
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<li><a href="rbafzmstsqlprocstmt.htm#sqlprocstmt">SQL-procedure-statement</a></li></ul>
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<p>For syntax and additional information on the SQL control statements see
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the following topics:</p>
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<ul>
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<li><a href="rbafzmstassignstmt.htm#assignstmt">assignment-statement</a></li>
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<li><a href="rbafzmstcallstmt.htm#callstmt">CALL statement</a></li>
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<li><a href="rbafzmstcasestmt.htm#casestmt">CASE statement</a></li>
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<li><a href="rbafzmstcompoundstmt.htm#compoundstmt">compound-statement</a></li>
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<li><a href="rbafzmstifstmt.htm#ifstmt">IF statement</a></li>
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<li><a href="rbafzmstforstmt.htm#forstmt">FOR statement</a></li>
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<li><a href="rbafzmstgetdiag2.htm#getdiag2">GET DIAGNOSTICS statement</a></li>
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<li><a href="rbafzmstgotostmt.htm#gotostmt">GOTO statement</a></li>
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<li><a href="rbafzmstiteratestmt.htm#iteratestmt">ITERATE statement</a></li>
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<li><a href="rbafzmstleavestmt.htm#leavestmt">LEAVE statement</a></li>
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<li><a href="rbafzmstloopstmt.htm#loopstmt">LOOP statement</a></li>
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<li><a href="rbafzmstrepeatstmt.htm#repeatstmt">REPEAT statement</a></li>
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<li><a href="rbafzmstresignalstmt.htm#resignalstmt">RESIGNAL statement</a></li>
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<li><a href="rbafzmstreturnstmt.htm#returnstmt">RETURN statement</a></li>
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<li><a href="rbafzmstsignalstmt.htm#signalstmt">SIGNAL statement</a></li>
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<li><a href="rbafzmstwhilestmt.htm#whilestmt">WHILE statement</a></li></ul>
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<hr /><br />
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[ <a href="#Top_Of_Page">Top of Page</a> | <a href="rbafzmstwvrr.htm">Previous Page</a> | <a href="rbafzmstrefsqlv.htm">Next Page</a> | <a href="rbafzmst02.htm#wq1">Contents</a> |
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<a href="rbafzmstindex.htm#index">Index</a> ]
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