diff --git a/doc/src/sgml/ref/fetch.sgml b/doc/src/sgml/ref/fetch.sgml
index b08ad4a191..b67b7ef3c7 100644
--- a/doc/src/sgml/ref/fetch.sgml
+++ b/doc/src/sgml/ref/fetch.sgml
@@ -1,5 +1,5 @@
@@ -22,7 +22,7 @@ PostgreSQL documentation
FETCH [ direction ] [ count ] { IN | FROM } cursor
-FETCH [ FORWARD | BACKWARD | RELATIVE ] [ # | ALL | NEXT | PRIOR ]
+FETCH [ FORWARD | BACKWARD | RELATIVE ] [ # | ALL | LAST | NEXT | PRIOR ]
{ IN | FROM } cursor
@@ -40,7 +40,7 @@ FETCH [ FORWARD | BACKWARD | RELATIVE ] [ #direction
- selector
+ direction
defines the fetch direction. It can be one of
the following:
@@ -50,7 +50,7 @@ FETCH [ FORWARD | BACKWARD | RELATIVE ] [ #
fetch next row(s). This is the default
- if selector is omitted.
+ if direction is omitted.
@@ -87,9 +87,9 @@ FETCH [ FORWARD | BACKWARD | RELATIVE ] [ ##
- A signed integer that specifies how many rows to fetch.
+ A signed integer constant that specifies how many rows to fetch.
Note that a negative integer is equivalent to changing the sense of
- FORWARD and BACKWARD. Zero re-fetches the current row.
+ FORWARD and BACKWARD. Zero re-fetches the current row, if any.
@@ -105,6 +105,17 @@ FETCH [ FORWARD | BACKWARD | RELATIVE ] [ #
+
+
+ LAST
+
+
+
+ Same as ALL, but conforms to SQL92 syntax.
+
+
+
+
NEXT
@@ -151,7 +162,8 @@ FETCH [ FORWARD | BACKWARD | RELATIVE ] [ #
- FETCH returns the results of the query defined by the specified cursor.
+ FETCH returns rows from the result of the query defined
+ by the specified cursor.
The following messages will be returned if the query fails:
@@ -200,10 +212,33 @@ WARNING: FETCH/ABSOLUTE not supported, using RELATIVE
If the number of rows remaining in the cursor is less
than #,
then only those available are fetched.
- Substituting the keyword ALL in place of a number will
+ Substituting the keyword ALL or LAST in place of a number will
cause all remaining rows in the cursor to be retrieved.
- Instances may be fetched in both FORWARD and BACKWARD
+ Rows may be fetched in both FORWARD and BACKWARD
directions. The default direction is FORWARD.
+
+
+
+ The cursor position can be before the first row of the query result, or on
+ any particular row of the result, or after the last row of the result.
+ When created, a cursor is positioned before the first row. After fetching
+ some rows, the cursor is positioned on the last row retrieved. A new
+ FETCH always steps one row in the specified direction
+ (if possible) before beginning to return rows. If the
+ FETCH requests more rows than available, the cursor is
+ left positioned after the last row of the query result (or before the first
+ row, in the case of a backward fetch). This will always be the case after
+ FETCH ALL.
+
+
+
+
+ A zero row count requests fetching the current row without moving the
+ cursor --- that is, re-fetching the most recently fetched row.
+ This will succeed unless the cursor is positioned before the
+ first row or after the last row; in which case, no row is returned.
+
+
@@ -213,7 +248,6 @@ WARNING: FETCH/ABSOLUTE not supported, using RELATIVE
FORWARD -1 is the same as BACKWARD 1.
-
@@ -224,11 +258,9 @@ WARNING: FETCH/ABSOLUTE not supported, using RELATIVE
- Note that the FORWARD and BACKWARD keywords are
+ Note that the FORWARD, BACKWARD, and ALL keywords are
PostgreSQL extensions.
- The SQL92 syntax is also supported, specified
- in the second form of the command. See below for details
- on compatibility issues.
+ See below for details on compatibility issues.
@@ -246,11 +278,11 @@ WARNING: FETCH/ABSOLUTE not supported, using RELATIVE
+
+ is used to define a cursor.
Use
- to change cursor position.
-
- will define a cursor.
+ to change cursor position without retrieving data.
Refer to
,
,
diff --git a/doc/src/sgml/ref/move.sgml b/doc/src/sgml/ref/move.sgml
index 5d4f1c8309..5b6f2671af 100644
--- a/doc/src/sgml/ref/move.sgml
+++ b/doc/src/sgml/ref/move.sgml
@@ -1,5 +1,5 @@
@@ -13,7 +13,7 @@ PostgreSQL documentation
MOVE
- position a cursor on a specified row of a table
+ reposition a cursor
@@ -21,9 +21,7 @@ PostgreSQL documentation
1999-07-20
-MOVE [ direction ]
- {count | LAST }
- { IN | FROM } cursor
+MOVE [ direction ] [ count ] { IN | FROM } cursor
@@ -35,12 +33,10 @@ MOVE [ direction ]
Description
- MOVE allows a user to move the cursor position a
- specified number of rows.
- MOVE works like the FETCH command,
- but only positions the cursor and does not return rows.
- LAST moves to the end
- of the cursor.
+ MOVE allows the user to move the cursor position a
+ specified number of rows, or all the way to the end or start of the query.
+ MOVE works exactly like the FETCH
+ command, except it only repositions the cursor and does not return rows.
Refer to
diff --git a/doc/src/sgml/release.sgml b/doc/src/sgml/release.sgml
index 2f3295cab8..55007a7d62 100644
--- a/doc/src/sgml/release.sgml
+++ b/doc/src/sgml/release.sgml
@@ -1,5 +1,5 @@
@@ -24,6 +24,7 @@ CDATA means the content is "SGML-free", so you can write without
worries about funny characters.
-->
estate;
- if (portal->atStart == false && portal->atEnd == false)
- on_row = true;
- MemoryContextSwitchTo(oldcontext);
+ on_row = (portal->atStart == false && portal->atEnd == false);
if (dest == None)
{
@@ -122,26 +119,25 @@ PerformPortalFetch(char *name,
}
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;
+ /*
+ * If we are sitting on a row, back up one so we can re-fetch it.
+ * If we are not sitting on a row, we still have to start up and
+ * shut down the executor so that the destination is initialized
+ * and shut down correctly; so keep going. Further down in the
+ * routine, count == 0 means we will retrieve no row.
+ */
+ if (on_row)
+ {
+ PerformPortalFetch(name, false /* backward */, 1L,
+ None, /* throw away output */
+ NULL /* do not modify the command tag */);
+ /* Set up to fetch one row forward */
+ count = 1;
+ forward = true;
+ }
}
}
- /* Internally, zero count processes all portal rows */
- if (count == LONG_MAX)
- count = 0;
-
/*
* switch into the portal context
*/
@@ -185,31 +181,45 @@ PerformPortalFetch(char *name,
*/
if (forward)
{
- if (portal->atEnd)
+ if (portal->atEnd || count == 0)
direction = NoMovementScanDirection;
else
direction = ForwardScanDirection;
- ExecutorRun(queryDesc, direction, (long) count);
+ /* In the executor, zero count processes all portal rows */
+ if (count == INT_MAX)
+ count = 0;
- if (estate->es_processed > 0)
- portal->atStart = false; /* OK to back up now */
- if (count <= 0 || (int) estate->es_processed < count)
- portal->atEnd = true; /* we retrieved 'em all */
+ ExecutorRun(queryDesc, direction, count);
+
+ if (direction != NoMovementScanDirection)
+ {
+ if (estate->es_processed > 0)
+ portal->atStart = false; /* OK to back up now */
+ if (count <= 0 || (long) estate->es_processed < count)
+ portal->atEnd = true; /* we retrieved 'em all */
+ }
}
else
{
- if (portal->atStart)
+ if (portal->atStart || count == 0)
direction = NoMovementScanDirection;
else
direction = BackwardScanDirection;
- ExecutorRun(queryDesc, direction, (long) count);
+ /* In the executor, zero count processes all portal rows */
+ if (count == INT_MAX)
+ count = 0;
- if (estate->es_processed > 0)
- portal->atEnd = false; /* OK to go forward now */
- if (count <= 0 || (int) estate->es_processed < count)
- portal->atStart = true; /* we retrieved 'em all */
+ ExecutorRun(queryDesc, direction, count);
+
+ if (direction != NoMovementScanDirection)
+ {
+ if (estate->es_processed > 0)
+ portal->atEnd = false; /* OK to go forward now */
+ if (count <= 0 || (long) estate->es_processed < count)
+ portal->atStart = true; /* we retrieved 'em all */
+ }
}
/* Return command status if wanted */
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 921099b792..1809d51546 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.390 2003/01/06 00:31:44 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.391 2003/01/08 00:22:27 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@@ -2594,7 +2594,7 @@ FetchStmt: FETCH direction fetch_how_many from_in name
if ($3 < 0)
{
$3 = -$3;
- $2 = (($2 == FORWARD)? BACKWARD: FORWARD);
+ $2 = (($2 == FORWARD) ? BACKWARD : FORWARD);
}
n->direction = $2;
n->howMany = $3;
@@ -2652,7 +2652,7 @@ FetchStmt: FETCH direction fetch_how_many from_in name
if ($3 < 0)
{
$3 = -$3;
- $2 = (($2 == FORWARD) ? BACKWARD: FORWARD);
+ $2 = (($2 == FORWARD) ? BACKWARD : FORWARD);
}
n->direction = $2;
n->howMany = $3;
@@ -2720,8 +2720,8 @@ direction: FORWARD { $$ = FORWARD; }
fetch_how_many:
Iconst { $$ = $1; }
| '-' Iconst { $$ = - $2; }
- | ALL { $$ = LONG_MAX; }
- | LAST { $$ = LONG_MAX; }
+ | ALL { $$ = INT_MAX; }
+ | LAST { $$ = INT_MAX; }
| NEXT { $$ = 1; }
| PRIOR { $$ = -1; }
;
@@ -7115,8 +7115,8 @@ unreserved_keyword:
| INVOKER
| ISOLATION
| KEY
- | LANGUAGE
| LANCOMPILER
+ | LANGUAGE
| LAST
| LEVEL
| LISTEN