http://postgres.cz/index.php?action=history&feed=atom&title=Condition_statementsCondition statements - Historie editací2026-05-13T02:18:59ZHistorie editací této stránkyMediaWiki 1.43.3http://postgres.cz/index.php?title=Condition_statements&diff=251&oldid=prev207.124.141.210: /* CASE Statement */2008-05-02T21:29:46Z<p><span class="autocomment">CASE Statement</span></p>
<p><b>Nová stránka</b></p><div>=== IF Statement ===<br />
Provide conditional execution based on the truth value of a condition.<br />
<br />
''Syntax''<br />
<pre><br />
IF boolean expression THEN<br />
sql/psm statements list<br />
[ELSEIF boolean expression THEN<br />
sql/psm statements list [ELSEIF ...]]<br />
[ELSE<br />
sql/psm statements list]<br />
END IF<br />
</pre><br />
<br />
=== CASE Statement ===<br />
Provide conditional execution based on truth of search conditions or on equality of operands. This statement is similar to SQL CASE statement with differences:<br />
* after keyword THEN is SQL/PSM statement (not value),<br />
* CASE statement is finished with pair of keywords - END CASE,<br />
* if all conditions are false and the CASE statement is missing the ELSE part then exception '20000' is raised.<br />
<br />
PL/pgPSM support comma-separated predicates in simple CASE statement.<br />
<br />
''Syntax''<br />
<pre><br />
-- simply CASE<br />
CASE expression<br />
WHEN comma separated list of values THEN sql/psm statements list<br />
[ WHEN comma separated list of values THEN sql/psm statements list [...]]<br />
END CASE<br />
<br />
-- searching CASE<br />
CASE<br />
WHEN boolean expression THEN sql/psm statements list<br />
[ WHEN boolean expression THEN sql/psm statements list [...]]<br />
END CASE<br />
</pre></div>207.124.141.210