Boszormenyi Zoltan wrote:
> >>> Ah, I didn't even see that that section needed to be updated. Good
> >>> catch. I'd suggest the following wording:
> >>>
> >>> For a <command>SELECT</command> or <command>CREATE TABLE AS</command>
> >>> command, the tag is SELECT rows... [and the rest as you have it]
> >>>
> >>> We should probably also retitle that section from "Retrieving Result
> >>> Information for Other Commands" to "Retrieving Other Result
> >>> Information" and adjust the text of the opening sentence similarly.
> >>>
> >>> Also I think you need to update the docs for PQcmdtuples to mention
> >>> that it not works for SELECT and CTAS.
> >>>
> >>>
> >> Ok, I will update libpq.sgml where this section resides.
> >> What's a CTA, btw? Do you mean CTE, a.k.a. "Common Table Expression"?
> >>
> >
> > Sorry, CTAS = CREATE TABLE AS SELECT.
> >
>
> Okay, new patch is attached. Please read the docs changes, and comment.
I have reviewed this patch and made some adjustments, attached. The
major change is that our return of "0 0" in certain cases must remain,
though I have improved the C comment explaining it with a separate CVS
commit:
/*
* If a command completion tag was supplied, use it. Otherwise use the
* portal's commandTag as the default completion tag.
*
* Exception: Clients expect INSERT/UPDATE/DELETE tags to have
* counts, so fake them with zeros. This can happen with DO INSTEAD
* rules if there is no replacement query of the same type as the
* original. We print "0 0" here because technically there is no
* query of the matching tag type, and printing a non-zero count for
* a different query type seems wrong, e.g. an INSERT that does
* an UPDATE instead should not print "0 1" if one row
* was updated. See QueryRewrite(), step 3, for details.
*/
I have removed the part of the patch that chagned "0 0"; it seems to
run fine without it. The rest of my adjustments were minor.
One major part of the patch seems to be the collection of the
PORTAL_ONE_SELECT switch label into the label below it, which is a nice
cleanup.
--
Bruce Momjian <br...@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +
Index: doc/src/sgml/libpq.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/libpq.sgml,v
retrieving revision 1.297
diff -c -c -r1.297 libpq.sgml
*** doc/src/sgml/libpq.sgml 5 Feb 2010 03:09:04 -0000 1.297
--- doc/src/sgml/libpq.sgml 14 Feb 2010 03:11:00 -0000
***************
*** 2869,2880 ****
</sect2>
<sect2 id="libpq-exec-nonselect">
! <title>Retrieving Result Information for Other Commands</title>
<para>
! These functions are used to extract information from
! <structname>PGresult</structname> objects that are not
! <command>SELECT</> results.
</para>
<variablelist>
--- 2869,2879 ----
</sect2>
<sect2 id="libpq-exec-nonselect">
! <title>Retrieving Other Result Information</title>
<para>
! These functions are used to extract other information from
! <structname>PGresult</structname> objects.
</para>
<variablelist>
***************
*** 2925,2936 ****
This function returns a string containing the number of rows
affected by the <acronym>SQL</> statement that generated the
<structname>PGresult</>. This function can only be used following
! the execution of an <command>INSERT</>, <command>UPDATE</>,
! <command>DELETE</>, <command>MOVE</>, <command>FETCH</>, or
! <command>COPY</> statement, or an <command>EXECUTE</> of a
! prepared query that contains an <command>INSERT</>,
! <command>UPDATE</>, or <command>DELETE</> statement. If the
! command that generated the <structname>PGresult</> was anything
else, <function>PQcmdTuples</> returns an empty string. The caller
should not free the return value directly. It will be freed when
the associated <structname>PGresult</> handle is passed to
--- 2924,2935 ----
This function returns a string containing the number of rows
affected by the <acronym>SQL</> statement that generated the
<structname>PGresult</>. This function can only be used following
! the execution of a <command>SELECT</>, <command>CREATE TABLE AS</>,
! <command>INSERT</>, <command>UPDATE</>, <command>DELETE</>,
! <command>MOVE</>, <command>FETCH</>, or <command>COPY</> statement,
! or an <command>EXECUTE</> of a prepared query that contains an
! <command>INSERT</>, <command>UPDATE</>, or <command>DELETE</>
statement.
! If the command that generated the <structname>PGresult</> was anything
else, <function>PQcmdTuples</> returns an empty string. The caller
should not free the return value directly. It will be freed when
the associated <structname>PGresult</> handle is passed to
Index: doc/src/sgml/protocol.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/protocol.sgml,v
retrieving revision 1.78
diff -c -c -r1.78 protocol.sgml
*** doc/src/sgml/protocol.sgml 3 Feb 2010 09:47:19 -0000 1.78
--- doc/src/sgml/protocol.sgml 14 Feb 2010 03:11:00 -0000
***************
*** 2222,2227 ****
--- 2222,2233 ----
</para>
<para>
+ For a <command>SELECT</command> or <command>CREATE TABLE AS</command>
+ command, the tag is <literal>SELECT
<replaceable>rows</replaceable></literal>
+ where <replaceable>rows</replaceable> is the number of rows retrieved.
+ </para>
+
+ <para>
For a <command>MOVE</command> command, the tag is
<literal>MOVE <replaceable>rows</replaceable></literal> where
<replaceable>rows</replaceable> is the number of rows the
Index: src/backend/tcop/pquery.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/tcop/pquery.c,v
retrieving revision 1.135
diff -c -c -r1.135 pquery.c
*** src/backend/tcop/pquery.c 13 Feb 2010 22:45:41 -0000 1.135
--- src/backend/tcop/pquery.c 14 Feb 2010 03:11:04 -0000
***************
*** 205,211 ****
switch (queryDesc->operation)
{
case CMD_SELECT:
! strcpy(completionTag, "SELECT");
break;
case CMD_INSERT:
if (queryDesc->estate->es_processed == 1)
--- 205,212 ----
switch (queryDesc->operation)
{
case CMD_SELECT:
! snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
! "SELECT %u",
queryDesc->estate->es_processed);
break;
case CMD_INSERT:
if (queryDesc->estate->es_processed == 1)
***************
*** 714,719 ****
--- 715,721 ----
char *completionTag)
{
bool result;
+ uint32 nprocessed;
ResourceOwner saveTopTransactionResourceOwner;
MemoryContext saveTopTransactionContext;
Portal saveActivePortal;
***************
*** 776,814 ****
switch (portal->strategy)
{
case PORTAL_ONE_SELECT:
- (void) PortalRunSelect(portal, true, count,
dest);
-
- /* we know the query is supposed to set the tag
*/
- if (completionTag && portal->commandTag)
- strcpy(completionTag,
portal->commandTag);
-
- /* Mark portal not active */
- portal->status = PORTAL_READY;
-
- /*
- * Since it's a forward fetch, say DONE iff
atEnd is now true.
- */
- result = portal->atEnd;
- break;
-
case PORTAL_ONE_RETURNING:
case PORTAL_UTIL_SELECT:
/*
* If we have not yet run the command, do so,
storing its
! * results in the portal's tuplestore.
*/
! if (!portal->holdStore)
FillPortalStore(portal, isTopLevel);
/*
* Now fetch desired portion of results.
*/
! (void) PortalRunSelect(portal, true, count,
dest);
! /* we know the query is supposed to set the tag
*/
if (completionTag && portal->commandTag)
! strcpy(completionTag,
portal->commandTag);
/* Mark portal not active */
portal->status = PORTAL_READY;
--- 778,812 ----
switch (portal->strategy)
{
case PORTAL_ONE_SELECT:
case PORTAL_ONE_RETURNING:
case PORTAL_UTIL_SELECT:
/*
* If we have not yet run the command, do so,
storing its
! * results in the portal's tuplestore. Do this
only for the
! * PORTAL_ONE_RETURNING and PORTAL_UTIL_SELECT
cases.
*/
! if (portal->strategy != PORTAL_ONE_SELECT &&
!portal->holdStore)
FillPortalStore(portal, isTopLevel);
/*
* Now fetch desired portion of results.
*/
! nprocessed = PortalRunSelect(portal, true,
count, dest);
! /*
! * If the portal result contains a command tag
and the caller
! * gave us a pointer to store it, copy it.
Patch the "SELECT"
! * tag to also provide the rowcount.
! */
if (completionTag && portal->commandTag)
! {
! if (strcmp(portal->commandTag,
"SELECT") == 0)
! snprintf(completionTag,
COMPLETION_TAG_BUFSIZE,
!
"SELECT %u", nprocessed);
! else
! strcpy(completionTag,
portal->commandTag);
! }
/* Mark portal not active */
portal->status = PORTAL_READY;
***************
*** 1331,1337 ****
{
if (portal->commandTag)
strcpy(completionTag, portal->commandTag);
! if (strcmp(completionTag, "INSERT") == 0)
strcpy(completionTag, "INSERT 0 0");
else if (strcmp(completionTag, "UPDATE") == 0)
strcpy(completionTag, "UPDATE 0");
--- 1329,1337 ----
{
if (portal->commandTag)
strcpy(completionTag, portal->commandTag);
! if (strcmp(completionTag, "SELECT") == 0)
! sprintf(completionTag, "SELECT 0 0");
! else if (strcmp(completionTag, "INSERT") == 0)
strcpy(completionTag, "INSERT 0 0");
else if (strcmp(completionTag, "UPDATE") == 0)
strcpy(completionTag, "UPDATE 0");
Index: src/interfaces/libpq/fe-exec.c
===================================================================
RCS file: /cvsroot/pgsql/src/interfaces/libpq/fe-exec.c,v
retrieving revision 1.208
diff -c -c -r1.208 fe-exec.c
*** src/interfaces/libpq/fe-exec.c 21 Jan 2010 18:43:25 -0000 1.208
--- src/interfaces/libpq/fe-exec.c 14 Feb 2010 03:11:04 -0000
***************
*** 2752,2758 ****
goto interpret_error; /* no space? */
p++;
}
! else if (strncmp(res->cmdStatus, "DELETE ", 7) == 0 ||
strncmp(res->cmdStatus, "UPDATE ", 7) == 0)
p = res->cmdStatus + 7;
else if (strncmp(res->cmdStatus, "FETCH ", 6) == 0)
--- 2752,2759 ----
goto interpret_error; /* no space? */
p++;
}
! else if (strncmp(res->cmdStatus, "SELECT ", 7) == 0 ||
! strncmp(res->cmdStatus, "DELETE ", 7) == 0 ||
strncmp(res->cmdStatus, "UPDATE ", 7) == 0)
p = res->cmdStatus + 7;
else if (strncmp(res->cmdStatus, "FETCH ", 6) == 0)
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