1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>ROLLBACK TO SAVEPOINT</title>
<link rel="stylesheet" href="stylesheet.css" type="text/css">
<link rev="made" href="pgsql-docs@postgresql.org">
<meta name="generator" content="DocBook XSL Stylesheets V1.70.0">
<link rel="start" href="index.html" title="PostgreSQL 8.1.4 Documentation">
<link rel="up" href="sql-commands.html" title="SQL Commands">
<link rel="prev" href="sql-rollback-prepared.html" title="ROLLBACK PREPARED">
<link rel="next" href="sql-savepoint.html" title="SAVEPOINT">
<link rel="copyright" href="ln-legalnotice.html" title="Legal Notice">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" lang="en">
<a name="sql-rollback-to"></a><div class="titlepage"></div>
<div class="refnamediv">
<h2>Name</h2>
<p>ROLLBACK TO SAVEPOINT — roll back to a savepoint</p>
</div>
<a name="id782177"></a><a name="id782188"></a><div class="refsynopsisdiv">
<h2>Synopsis</h2>
<pre class="synopsis">ROLLBACK [ WORK | TRANSACTION ] TO [ SAVEPOINT ] <em class="replaceable"><code>savepoint_name</code></em></pre>
</div>
<div class="refsect1" lang="en">
<a name="id782210"></a><h2>Description</h2>
<p> Roll back all commands that were executed after the savepoint was
established. The savepoint remains valid and can be rolled back to
again later, if needed.
</p>
<p> <code class="command">ROLLBACK TO SAVEPOINT</code> implicitly destroys all savepoints that
were established after the named savepoint.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id782230"></a><h2>Parameters</h2>
<div class="variablelist"><dl>
<dt><span class="term"><em class="replaceable"><code>savepoint_name</code></em></span></dt>
<dd><p> The savepoint to roll back to.
</p></dd>
</dl></div>
</div>
<div class="refsect1" lang="en">
<a name="id782248"></a><h2>Notes</h2>
<p> Use <a href="sql-release-savepoint.html">RELEASE SAVEPOINT</a> to destroy a savepoint without
discarding the effects of commands executed after it was established.
</p>
<p> Specifying a savepoint name that has not been established is an error.
</p>
<p> Cursors have somewhat non-transactional behavior with respect to
savepoints. Any cursor that is opened inside a savepoint will be closed
when the savepoint is rolled back. If a previously opened cursor is
affected by a
<code class="command">FETCH</code> command inside a savepoint that is later rolled
back, the cursor position remains at the position that <code class="command">FETCH</code>
left it pointing to (that is, <code class="command">FETCH</code> is not rolled back).
Closing a cursor is not undone by rolling back, either.
A cursor whose execution causes a transaction to abort is put in a
can't-execute state, so while the transaction can be restored using
<code class="command">ROLLBACK TO SAVEPOINT</code>, the cursor can no longer be used.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id782312"></a><h2>Examples</h2>
<p> To undo the effects of the commands executed after <code class="literal">my_savepoint</code>
was established:
</p>
<pre class="programlisting">ROLLBACK TO SAVEPOINT my_savepoint;</pre>
<p>
</p>
<p> Cursor positions are not affected by savepoint rollback:
</p>
<pre class="programlisting">BEGIN;
DECLARE foo CURSOR FOR SELECT 1 UNION SELECT 2;
SAVEPOINT foo;
FETCH 1 FROM foo;
?column?
----------
1
ROLLBACK TO SAVEPOINT foo;
FETCH 1 FROM foo;
?column?
----------
2
COMMIT;</pre>
<p>
</p>
</div>
<div class="refsect1" lang="en">
<a name="id782347"></a><h2>Compatibility</h2>
<p> The <acronym class="acronym">SQL</acronym> standard specifies that the key word
<code class="literal">SAVEPOINT</code> is mandatory, but <span class="productname">PostgreSQL</span>
and <span class="productname">Oracle</span> allow it to be omitted. SQL allows
only <code class="literal">WORK</code>, not <code class="literal">TRANSACTION</code>, as a noise word
after <code class="literal">ROLLBACK</code>. Also, SQL has an optional clause
<code class="literal">AND [ NO ] CHAIN</code> which is not currently supported by
<span class="productname">PostgreSQL</span>. Otherwise, this command conforms to
the SQL standard.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id782414"></a><h2>See Also</h2>
<span class="simplelist"><a href="sql-begin.html">BEGIN</a>, <a href="sql-commit.html">COMMIT</a>, <a href="sql-release-savepoint.html">RELEASE SAVEPOINT</a>, <a href="sql-rollback.html">ROLLBACK</a>, <a href="sql-savepoint.html">SAVEPOINT</a></span>
</div>
</div></body>
</html>
|
