beginning/end of cursor.
Have MOVE return 0/1 depending on cursor position.
Matches SQL spec.
Pass cursor counter from parser as a long rather than int.
Doc updates.
<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/ref/fetch.sgml,v 1.21 2002/04/21 19:02:39 thomas Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/ref/fetch.sgml,v 1.22 2002/12/30 15:31:47 momjian Exp $
PostgreSQL documentation
-->
<para>
A signed integer that specifies how many rows to fetch.
Note that a negative integer is equivalent to changing the sense of
- FORWARD and BACKWARD.
+ FORWARD and BACKWARD. Zero re-fetches the current row.
</para>
</listitem>
</varlistentry>
</listitem>
</varlistentry>
- <varlistentry>
- <term><computeroutput>
-ERROR: FETCH/RELATIVE at current position is not supported
- </computeroutput></term>
- <listitem>
- <para>
- <acronym>SQL92</acronym> allows one to repetitively retrieve the cursor
- at its <quote>current position</quote> using the syntax
- <synopsis>
-FETCH RELATIVE 0 FROM <replaceable class="PARAMETER">cursor</replaceable>.
- </synopsis>
- </para>
-
- <para>
- <productname>PostgreSQL</productname> does not currently support
- this notion; in fact the value zero is reserved to indicate that
- all rows should be retrieved and is equivalent to specifying the ALL keyword.
- If the RELATIVE keyword has been used, <productname>PostgreSQL</productname>
- assumes that the user intended <acronym>SQL92</acronym> behavior
- and returns this error message.
- </para>
- </listitem>
- </varlistentry>
-
</variablelist>
</para>
</refsect2>
<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/ref/move.sgml,v 1.14 2002/11/13 00:44:08 momjian Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/ref/move.sgml,v 1.15 2002/12/30 15:31:47 momjian Exp $
PostgreSQL documentation
-->
Description
</title>
<para>
- <command>MOVE</command> allows a user to move cursor position a specified
- number of rows.
+ <command>MOVE</command> allows a user to move the cursor position a
+ specified number of rows.
<command>MOVE</command> works like the <command>FETCH</command> command,
but only positions the cursor and does not return rows.
<replaceable class="PARAMETER">LAST</replaceable> moves to the end
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/commands/portalcmds.c,v 1.6 2002/12/15 16:17:42 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/portalcmds.c,v 1.7 2002/12/30 15:31:47 momjian Exp $
*
*-------------------------------------------------------------------------
*/
void
PerformPortalFetch(char *name,
bool forward,
- int count,
+ long count,
CommandDest dest,
char *completionTag)
{
return;
}
- /* If zero count, we are done */
+ /* If zero count, handle specially */
if (count == 0)
- return;
+ {
+ bool on_row = false;
+
+ /* Are we sitting on a row? */
+ oldcontext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
+ queryDesc = PortalGetQueryDesc(portal);
+ estate = queryDesc->estate;
+ if (portal->atStart == false && portal->atEnd == false)
+ on_row = true;
+ MemoryContextSwitchTo(oldcontext);
+
+ if (dest == None)
+ {
+ /* MOVE 0 returns 0/1 based on if FETCH 0 would return a row */
+ if (completionTag && on_row)
+ strcpy(completionTag, "MOVE 1");
+ return;
+ }
+ else
+ {
+ /* If we are not on a row, FETCH 0 returns nothing */
+ if (!on_row)
+ return;
+
+ /* Since we are sitting on a row, return the row */
+ /* Back up so we can reread the row */
+ PerformPortalFetch(name, false /* backward */, 1,
+ None, /* throw away output */
+ NULL /* do not modify the command tag */);
+
+ /* Set up to fetch one row */
+ count = 1;
+ forward = true;
+ }
+ }
/* Internally, zero count processes all portal rows */
- if (count == INT_MAX)
+ if (count == LONG_MAX)
count = 0;
-
+
/*
* switch into the portal context
*/
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.388 2002/12/12 20:35:13 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.389 2002/12/30 15:31:47 momjian Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
FetchStmt: FETCH direction fetch_how_many from_in name
{
FetchStmt *n = makeNode(FetchStmt);
- if ($2 == RELATIVE)
- {
- if ($3 == 0)
- elog(ERROR,
- "FETCH / RELATIVE at current position is not supported");
- $2 = FORWARD;
- }
if ($3 < 0)
{
$3 = -$3;
| FETCH direction from_in name
{
FetchStmt *n = makeNode(FetchStmt);
- if ($2 == RELATIVE)
- {
- $2 = FORWARD;
- }
n->direction = $2;
n->howMany = 1;
n->portalname = $4;
direction: FORWARD { $$ = FORWARD; }
| BACKWARD { $$ = BACKWARD; }
- | RELATIVE { $$ = RELATIVE; }
+ | RELATIVE { $$ = FORWARD; }
| ABSOLUTE
{
elog(NOTICE,
"FETCH / ABSOLUTE not supported, using RELATIVE");
- $$ = RELATIVE;
+ $$ = FORWARD;
}
;
fetch_how_many:
Iconst { $$ = $1; }
| '-' Iconst { $$ = - $2; }
- | ALL { $$ = INT_MAX; }
- | LAST { $$ = INT_MAX; }
+ | ALL { $$ = LONG_MAX; }
+ | LAST { $$ = LONG_MAX; }
| NEXT { $$ = 1; }
| PRIOR { $$ = -1; }
;
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.185 2002/12/06 05:00:31 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.186 2002/12/30 15:31:48 momjian Exp $
*
*-------------------------------------------------------------------------
*/
FetchStmt *stmt = (FetchStmt *) parsetree;
char *portalName = stmt->portalname;
bool forward;
- int count;
+ long count;
forward = (bool) (stmt->direction == FORWARD);
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: portalcmds.h,v 1.3 2002/11/13 00:44:09 momjian Exp $
+ * $Id: portalcmds.h,v 1.4 2002/12/30 15:31:50 momjian Exp $
*
*-------------------------------------------------------------------------
*/
* BadArg if forward invalid.
* "ERROR" if portal not found.
*/
-extern void PerformPortalFetch(char *name, bool forward, int count,
+extern void PerformPortalFetch(char *name, bool forward, long count,
CommandDest dest, char *completionTag);
/*
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: parsenodes.h,v 1.223 2002/12/12 20:35:16 tgl Exp $
+ * $Id: parsenodes.h,v 1.224 2002/12/30 15:31:51 momjian Exp $
*
*-------------------------------------------------------------------------
*/
{
NodeTag type;
int direction; /* FORWARD or BACKWARD */
- int howMany; /* amount to fetch */
+ long howMany; /* amount to fetch */
char *portalname; /* name of portal (cursor) */
bool ismove; /* TRUE if MOVE */
} FetchStmt;
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