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Code review for SELECT INTO STRICT patch: use saner choices of error

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SQLSTATEs, fix some documentation problems.
This commit is contained in:
Tom Lane
2006-06-16 23:29:27 +00:00
parent 3ba3e6c8ce
commit c892643a3c
7 changed files with 57 additions and 38 deletions
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14
doc/src/sgml/errcodes.sgml
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@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/errcodes.sgml,v 1.19 2006/06/16 22:41:45 tgl Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/errcodes.sgml,v 1.20 2006/06/16 23:29:26 tgl Exp $ -->
<appendix id="errcodes-appendix">
<title><productname>PostgreSQL</productname> Error Codes</title>
@ -1344,6 +1344,18 @@
<entry>raise_exception</entry>
</row>
<row>
<entry><literal>P0002</literal></entry>
<entry>NO DATA FOUND</entry>
<entry>no_data_found</entry>
</row>
<row>
<entry><literal>P0003</literal></entry>
<entry>TOO MANY ROWS</entry>
<entry>too_many_rows</entry>
</row>
<row>
<entry spanname="span13"><emphasis role="bold">Class XX &mdash; Internal Error</></entry>

43
doc/src/sgml/plpgsql.sgml
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@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.96 2006/06/15 18:02:22 momjian Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.97 2006/06/16 23:29:26 tgl Exp $ -->
<chapter id="plpgsql">
<title><application>PL/pgSQL</application> - <acronym>SQL</acronym> Procedural Language</title>
@ -1076,8 +1076,8 @@ tax := subtotal * 0.06;
</indexterm>
<para>
The result of a <command>SELECT</command> command yielding multiple columns (but
only one row) can be assigned to a record variable, row-type
The result of a <command>SELECT</command> command yielding multiple
columns (but only one row) can be assigned to a record variable, row-type
variable, or list of scalar variables. This is done by:
<synopsis>
@ -1126,23 +1126,24 @@ SELECT INTO <optional>STRICT</optional> <replaceable>target</replaceable> <repla
<replaceable>target</replaceable> will be set to the first row
returned by the query, or if the query returned no rows,
null values are assigned. (Note that <quote>the first row</> is not
well-defined unless you've used <literal>ORDER BY</>.)
You can check the special <literal>FOUND</literal> variable to
determine if any rows were found:
well-defined unless you've used <literal>ORDER BY</>.) Any result rows
after the first row are discarded.
You can check the special <literal>FOUND</literal> variable (see
<xref linkend="plpgsql-statements-diagnostics">) to
determine whether a row was returned:
<programlisting>
SELECT INTO STRICT myrec * FROM emp WHERE empname = myname;
SELECT INTO myrec * FROM emp WHERE empname = myname;
IF NOT FOUND THEN
RAISE EXCEPTION 'employee % not found', myname;
END IF;
</programlisting>
<para>
If the <literal>STRICT</literal> option is specified, a query must
If the <literal>STRICT</literal> option is specified, the query must
return exactly one row or a run-time error will be thrown, either
<literal>NO_DATA_FOUND</> (no rows) or <literal>TOO_MANY_ROWS</>
(more than one row). You can must use exception blocks to determine
the number of rows generated by the query:
(more than one row). You can use an exception block if you wish
to catch the error, for example:
<programlisting>
BEGIN;
@ -1154,11 +1155,17 @@ BEGIN;
RAISE EXCEPTION 'employee % not unique', myname;
END;
</programlisting>
Only <command>SELECT INTO STRICT</command> allows you to check if more
than one row was retrieved. <command>SELECT INTO STRICT</command>
matches Oracle's PL/SQL <command>SELECT INTO</command> behavior.
Successful execution of <command>SELECT INTO STRICT</command>
always sets <literal>FOUND</literal> to true.
</para>
<note>
<para>
<command>SELECT INTO STRICT</command> matches the behavior of
Oracle PL/SQL's <command>SELECT INTO</command> statement.
</para>
</note>
</sect2>
<sect2 id="plpgsql-statements-perform">
@ -1987,7 +1994,7 @@ END LOOP <optional> <replaceable>label</replaceable> </optional>;
the loop. If the <literal>BY</> clause isn't specified the iteration
step is 1 otherwise it's the value specified in the <literal>BY</>
clause. If <literal>REVERSE</> is specified then the step value is
considered negative.
considered negative.
</para>
<para>
@ -2764,7 +2771,7 @@ RAISE EXCEPTION 'Nonexistent ID --> %', user_id;
<para>
Data type <type>name</type>; the name of the table that caused the trigger
invocation. This is now deprecated, and could disappear in a future
release. Use <literal>TG_TABLE_NAME</> instead.
release. Use <literal>TG_TABLE_NAME</> instead.
</para>
</listitem>
</varlistentry>
@ -2774,7 +2781,7 @@ RAISE EXCEPTION 'Nonexistent ID --> %', user_id;
<listitem>
<para>
Data type <type>name</type>; the name of the table that
caused the trigger invocation.
caused the trigger invocation.
</para>
</listitem>
</varlistentry>
@ -2784,7 +2791,7 @@ RAISE EXCEPTION 'Nonexistent ID --> %', user_id;
<listitem>
<para>
Data type <type>name</type>; the name of the schema of the
table that caused the trigger invocation.
table that caused the trigger invocation.
</para>
</listitem>
</varlistentry>