blob: 3cdb5d67a218b76c5470205c87e2700e6cbab719 (
plain)
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
|
<!-- $Header: /cvsroot/pgsql/doc/src/sgml/ref/set_constraints.sgml,v 1.1 2000/06/18 21:24:54 petere Exp $ -->
<refentry id="SQL-SET-CONSTRAINTS">
<refmeta>
<refentrytitle id="SQL-SET-CONSTRAINTS-title">SET CONSTRAINTS</refentrytitle>
<refmiscinfo>SQL - Language Statements</refmiscinfo>
</refmeta>
<refnamediv>
<refname>SET CONSTRAINTS</refname>
<refpurpose>Set the constraint mode of the current SQL-transaction</refpurpose>
</refnamediv>
<refsynopsisdiv>
<refsynopsisdivinfo>
<date>2000-06-01</date>
</refsynopsisdivinfo>
<synopsis>
SET CONSTRAINTS { ALL | <replaceable class="parameter">constraint</replaceable> [, ...] } { DEFERRED | IMMEDIATE }
</synopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
<command>SET CONSTRAINTS</command> sets the behavior of constraint
evaluation in the current transaction. In
<option>IMMEDIATE</option> mode, constraints are checked at the end
of each statement. In <option>DEFERRED</option> mode, constraints
are not checked until transaction commit.
</para>
<para>
Upon creation, a constraint is always give one of three
characteristics: <option>INITIALLY DEFERRED</option>,
<option>INITIALLY IMMEDIATE DEFERRABLE</option>, or
<option>INITIALLY IMMEDIATE NOT DEFERRABLE</option>. The third
class is not affected by the <command>SET CONSTRAINTS</command>
command.
</para>
<para>
Currently, only foreign key constraints are affected by this
setting. Check and unique constraints are always effectively
initially immediate not deferrable.
</para>
</refsect1>
<refsect1>
<title>Compatibility</title>
<para>
SQL92, SQL99
</para>
</refsect1>
</refentry>
|
