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

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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@ -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>

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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">

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@ -11,7 +11,7 @@
*
* Copyright (c) 2003-2006, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.19 2006/03/05 15:59:07 momjian Exp $
* $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.20 2006/06/16 23:29:26 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -331,6 +331,8 @@
/* Class P0 - PL/pgSQL Error (PostgreSQL-specific error class) */
#define ERRCODE_PLPGSQL_ERROR MAKE_SQLSTATE('P','0', '0','0','0')
#define ERRCODE_RAISE_EXCEPTION MAKE_SQLSTATE('P','0', '0','0','1')
#define ERRCODE_NO_DATA_FOUND MAKE_SQLSTATE('P','0', '0','0','2')
#define ERRCODE_TOO_MANY_ROWS MAKE_SQLSTATE('P','0', '0','0','3')
/* Class XX - Internal Error (PostgreSQL-specific error class) */
/* (this is for "can't-happen" conditions and software bugs) */

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@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.92 2006/06/15 18:02:22 momjian Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.93 2006/06/16 23:29:26 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -157,7 +157,6 @@ static void check_labels(const char *start_label,
%token K_ELSE
%token K_ELSIF
%token K_END
%token K_STRICT
%token K_EXCEPTION
%token K_EXECUTE
%token K_EXIT
@ -187,6 +186,7 @@ static void check_labels(const char *start_label,
%token K_RETURN_NEXT
%token K_REVERSE
%token K_SELECT
%token K_STRICT
%token K_THEN
%token K_TO
%token K_TYPE

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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.172 2006/06/16 18:42:23 tgl Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.173 2006/06/16 23:29:27 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1721,7 +1721,7 @@ exec_stmt_select(PLpgSQL_execstate *estate, PLpgSQL_stmt_select *stmt)
{
if (stmt->strict)
ereport(ERROR,
(errcode(ERRCODE_NO_DATA),
(errcode(ERRCODE_NO_DATA_FOUND),
errmsg("query returned no rows")));
/* set the target to NULL(s) */
@ -1732,7 +1732,7 @@ exec_stmt_select(PLpgSQL_execstate *estate, PLpgSQL_stmt_select *stmt)
if (n > 1 && stmt->strict)
ereport(ERROR,
(errcode(ERRCODE_CARDINALITY_VIOLATION),
(errcode(ERRCODE_TOO_MANY_ROWS),
errmsg("query returned more than one row")));
/*

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@ -9,7 +9,7 @@
*
* Copyright (c) 2003-2006, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/pl/plpgsql/src/plerrcodes.h,v 1.8 2006/06/15 18:02:22 momjian Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/plerrcodes.h,v 1.9 2006/06/16 23:29:27 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -711,6 +711,14 @@
"raise_exception", ERRCODE_RAISE_EXCEPTION
},
{
"no_data_found", ERRCODE_NO_DATA_FOUND
},
{
"too_many_rows", ERRCODE_TOO_MANY_ROWS
},
{
"internal_error", ERRCODE_INTERNAL_ERROR
},
@ -722,13 +730,3 @@
{
"index_corrupted", ERRCODE_INDEX_CORRUPTED
},
{
"no_data_found", ERRCODE_NO_DATA
},
{
"too_many_rows", ERRCODE_CARDINALITY_VIOLATION
},

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@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.51 2006/06/15 18:02:22 momjian Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.52 2006/06/16 23:29:27 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -129,7 +129,6 @@ else { return K_ELSE; }
elseif { return K_ELSIF; }
elsif { return K_ELSIF; }
end { return K_END; }
strict { return K_STRICT; }
exception { return K_EXCEPTION; }
execute { return K_EXECUTE; }
exit { return K_EXIT; }
@ -158,6 +157,7 @@ return { return K_RETURN; }
reverse { return K_REVERSE; }
row_count { return K_ROW_COUNT; }
select { return K_SELECT; }
strict { return K_STRICT; }
then { return K_THEN; }
to { return K_TO; }
type { return K_TYPE; }