Cause FETCH 1 to return the current cursor row, or zero if at
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.
This commit is contained in:
Bruce Momjian
parent
a0fa0117a5
commit
33f0108df8
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@ -1,5 +1,5 @@
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<!--
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$Header: /cvsroot/pgsql/doc/src/sgml/ref/fetch.sgml,v 1.21 2002/04/21 19:02:39 thomas Exp $
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$Header: /cvsroot/pgsql/doc/src/sgml/ref/fetch.sgml,v 1.22 2002/12/30 15:31:47 momjian Exp $
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PostgreSQL documentation
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-->
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@ -89,7 +89,7 @@ FETCH [ FORWARD | BACKWARD | RELATIVE ] [ <replaceable class="PARAMETER">#</repl
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<para>
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A signed integer that specifies how many rows to fetch.
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Note that a negative integer is equivalent to changing the sense of
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FORWARD and BACKWARD.
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FORWARD and BACKWARD. Zero re-fetches the current row.
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</para>
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</listitem>
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</varlistentry>
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@ -180,30 +180,6 @@ WARNING: FETCH/ABSOLUTE not supported, using RELATIVE
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><computeroutput>
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ERROR: FETCH/RELATIVE at current position is not supported
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</computeroutput></term>
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<listitem>
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<para>
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<acronym>SQL92</acronym> allows one to repetitively retrieve the cursor
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at its <quote>current position</quote> using the syntax
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<synopsis>
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FETCH RELATIVE 0 FROM <replaceable class="PARAMETER">cursor</replaceable>.
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</synopsis>
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</para>
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<para>
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<productname>PostgreSQL</productname> does not currently support
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this notion; in fact the value zero is reserved to indicate that
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all rows should be retrieved and is equivalent to specifying the ALL keyword.
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If the RELATIVE keyword has been used, <productname>PostgreSQL</productname>
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assumes that the user intended <acronym>SQL92</acronym> behavior
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and returns this error message.
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</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</para>
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</refsect2>
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@ -1,5 +1,5 @@
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<!--
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$Header: /cvsroot/pgsql/doc/src/sgml/ref/move.sgml,v 1.14 2002/11/13 00:44:08 momjian Exp $
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$Header: /cvsroot/pgsql/doc/src/sgml/ref/move.sgml,v 1.15 2002/12/30 15:31:47 momjian Exp $
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PostgreSQL documentation
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-->
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@ -35,8 +35,8 @@ MOVE [ <replaceable class="PARAMETER">direction</replaceable> ]
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Description
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</title>
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<para>
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<command>MOVE</command> allows a user to move cursor position a specified
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number of rows.
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<command>MOVE</command> allows a user to move the cursor position a
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specified number of rows.
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<command>MOVE</command> works like the <command>FETCH</command> command,
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but only positions the cursor and does not return rows.
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<replaceable class="PARAMETER">LAST</replaceable> moves to the end
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@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/commands/portalcmds.c,v 1.6 2002/12/15 16:17:42 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/commands/portalcmds.c,v 1.7 2002/12/30 15:31:47 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -65,7 +65,7 @@ PortalCleanup(Portal portal)
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void
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PerformPortalFetch(char *name,
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bool forward,
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int count,
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long count,
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CommandDest dest,
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char *completionTag)
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{
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@ -100,14 +100,48 @@ PerformPortalFetch(char *name,
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return;
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}
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/* If zero count, we are done */
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/* If zero count, handle specially */
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if (count == 0)
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return;
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{
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bool on_row = false;
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/* Are we sitting on a row? */
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oldcontext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
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queryDesc = PortalGetQueryDesc(portal);
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estate = queryDesc->estate;
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if (portal->atStart == false && portal->atEnd == false)
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on_row = true;
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MemoryContextSwitchTo(oldcontext);
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if (dest == None)
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{
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/* MOVE 0 returns 0/1 based on if FETCH 0 would return a row */
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if (completionTag && on_row)
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strcpy(completionTag, "MOVE 1");
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return;
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}
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else
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{
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/* If we are not on a row, FETCH 0 returns nothing */
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if (!on_row)
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return;
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/* Since we are sitting on a row, return the row */
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/* Back up so we can reread the row */
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PerformPortalFetch(name, false /* backward */, 1,
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None, /* throw away output */
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NULL /* do not modify the command tag */);
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/* Set up to fetch one row */
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count = 1;
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forward = true;
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}
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}
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/* Internally, zero count processes all portal rows */
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if (count == INT_MAX)
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if (count == LONG_MAX)
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count = 0;
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/*
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* switch into the portal context
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*/
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@ -11,7 +11,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.388 2002/12/12 20:35:13 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.389 2002/12/30 15:31:47 momjian Exp $
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*
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* HISTORY
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* AUTHOR DATE MAJOR EVENT
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@ -2591,13 +2591,6 @@ comment_text:
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FetchStmt: FETCH direction fetch_how_many from_in name
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{
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FetchStmt *n = makeNode(FetchStmt);
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if ($2 == RELATIVE)
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{
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if ($3 == 0)
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elog(ERROR,
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"FETCH / RELATIVE at current position is not supported");
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$2 = FORWARD;
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}
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if ($3 < 0)
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{
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$3 = -$3;
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@ -2629,10 +2622,6 @@ FetchStmt: FETCH direction fetch_how_many from_in name
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| FETCH direction from_in name
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{
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FetchStmt *n = makeNode(FetchStmt);
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if ($2 == RELATIVE)
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{
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$2 = FORWARD;
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}
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n->direction = $2;
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n->howMany = 1;
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n->portalname = $4;
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@ -2719,20 +2708,20 @@ FetchStmt: FETCH direction fetch_how_many from_in name
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direction: FORWARD { $$ = FORWARD; }
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| BACKWARD { $$ = BACKWARD; }
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| RELATIVE { $$ = RELATIVE; }
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| RELATIVE { $$ = FORWARD; }
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| ABSOLUTE
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{
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elog(NOTICE,
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"FETCH / ABSOLUTE not supported, using RELATIVE");
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$$ = RELATIVE;
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$$ = FORWARD;
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}
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;
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fetch_how_many:
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Iconst { $$ = $1; }
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| '-' Iconst { $$ = - $2; }
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| ALL { $$ = INT_MAX; }
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| LAST { $$ = INT_MAX; }
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| ALL { $$ = LONG_MAX; }
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| LAST { $$ = LONG_MAX; }
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| NEXT { $$ = 1; }
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| PRIOR { $$ = -1; }
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;
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@ -10,7 +10,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.185 2002/12/06 05:00:31 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.186 2002/12/30 15:31:48 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -257,7 +257,7 @@ ProcessUtility(Node *parsetree,
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FetchStmt *stmt = (FetchStmt *) parsetree;
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char *portalName = stmt->portalname;
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bool forward;
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int count;
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long count;
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forward = (bool) (stmt->direction == FORWARD);
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@ -7,7 +7,7 @@
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* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $Id: portalcmds.h,v 1.3 2002/11/13 00:44:09 momjian Exp $
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* $Id: portalcmds.h,v 1.4 2002/12/30 15:31:50 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -25,7 +25,7 @@
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* BadArg if forward invalid.
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* "ERROR" if portal not found.
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*/
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extern void PerformPortalFetch(char *name, bool forward, int count,
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extern void PerformPortalFetch(char *name, bool forward, long count,
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CommandDest dest, char *completionTag);
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/*
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@ -7,7 +7,7 @@
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* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $Id: parsenodes.h,v 1.223 2002/12/12 20:35:16 tgl Exp $
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* $Id: parsenodes.h,v 1.224 2002/12/30 15:31:51 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -1198,7 +1198,7 @@ typedef struct FetchStmt
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{
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NodeTag type;
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int direction; /* FORWARD or BACKWARD */
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int howMany; /* amount to fetch */
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long howMany; /* amount to fetch */
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char *portalname; /* name of portal (cursor) */
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bool ismove; /* TRUE if MOVE */
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} FetchStmt;
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