database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-27 12:41:57 +03:00
Code Activity

FOUND patch was a bit over-enthusiastic: SQL commands that are not

Browse Source 
INSERT, UPDATE, or DELETE shouldn't change FOUND.  IMHO anyway.
Also, try to make documentation a little clearer.
This commit is contained in:
Tom Lane
2002-08-29 04:12:03 +00:00
parent 5241a6259f
commit 99fd5cbd41
2 changed files with 62 additions and 64 deletions
Download Patch File Download Diff File Expand all files Collapse all files

110
doc/src/sgml/plpgsql.sgml
View File

@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/plpgsql.sgml,v 1.3 2002/08/22 00:01:40 tgl Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/plpgsql.sgml,v 1.4 2002/08/29 04:12:02 tgl Exp $
-->
<chapter id="plpgsql">
@ -852,58 +852,10 @@ SELECT INTO <replaceable>target</replaceable> <replaceable>expressions</replacea
</para>
<para>
There is a special variable named <literal>FOUND</literal> of
type <type>boolean</type>. The initial value of
<literal>FOUND</literal> is false; it is set to true when one of
the following events occurs:
<itemizedlist>
<listitem>
<para>
A SELECT INTO statement is executed, and it returns one or
more rows.
</para>
</listitem>
<listitem>
<para>
A UPDATE, INSERT, or DELETE statement is executed, and it
affects one or more rows.
</para>
</listitem>
<listitem>
<para>
A PERFORM statement is executed, and it discards one or more
rows.
</para>
</listitem>
<listitem>
<para>
A FETCH statement is executed, and it returns an additional
row.
</para>
</listitem>
<listitem>
<para>
A FOR statement is executed, and it iterates one or more
times. This applies to all three variants of the FOR statement
(integer FOR loops, record-set FOR loops, and dynamic
record-set FOR loops). <literal>FOUND</literal> is only set
when the FOR loop exits: inside the execution of the loop,
<literal>FOUND</literal> is not modified, although it may be
set by the execution of other statements.
</para>
</listitem>
</itemizedlist>
If none of these events occur, <literal>FOUND</literal> is set to
false. <literal>FOUND</literal> is a local variable; any changes
to it effect only the current <application>PL/pgSQL</application>
function.
</para>
<para>
You can use <literal>FOUND</literal> immediately after a SELECT
INTO statement to determine whether the assignment was successful
(that is, at least one row was was returned by the SELECT
statement). For example:
You can use <literal>FOUND</literal> immediately after a SELECT
INTO statement to determine whether the assignment was successful
(that is, at least one row was was returned by the SELECT
statement). For example:
<programlisting>
SELECT INTO myrec * FROM EMP WHERE empname = myname;
@ -1116,6 +1068,58 @@ GET DIAGNOSTICS <replaceable>variable</replaceable> = <replaceable>item</replace
</programlisting>
</informalexample>
</para>
<para>
There is a special variable named <literal>FOUND</literal> of
type <type>boolean</type>. <literal>FOUND</literal> starts out
false within each <application>PL/pgSQL</application> function.
It is set by each of the following types of statements:
<itemizedlist>
<listitem>
<para>
A SELECT INTO statement sets <literal>FOUND</literal>
true if it returns a row, false if no row is returned.
</para>
</listitem>
<listitem>
<para>
A PERFORM statement sets <literal>FOUND</literal>
true if it produces (discards) a row, false if no row is
produced.
</para>
</listitem>
<listitem>
<para>
UPDATE, INSERT, and DELETE statements set
<literal>FOUND</literal> true if at least one row is
affected, false if no row is affected.
</para>
</listitem>
<listitem>
<para>
A FETCH statement sets <literal>FOUND</literal>
true if it returns a row, false if no row is returned.
</para>
</listitem>
<listitem>
<para>
A FOR statement sets <literal>FOUND</literal>
true if it iterates one or more times, else false.
This applies to all three variants of the FOR statement
(integer FOR loops, record-set FOR loops, and dynamic
record-set FOR loops). <literal>FOUND</literal> is only set
when the FOR loop exits: inside the execution of the loop,
<literal>FOUND</literal> is not modified by the FOR statement,
although it may be changed by the execution of other
statements within the loop body.
</para>
</listitem>
</itemizedlist>
<literal>FOUND</literal> is a local variable; any changes
to it affect only the current <application>PL/pgSQL</application>
function.
</para>
</sect2>
</sect1>