database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-31 22:04:40 +03:00
Code Activity

DROP IF EXISTS for columns and constraints. Andres Freund.

Browse Source
This commit is contained in:
Andrew Dunstan
2009-07-20 02:42:28 +00:00
parent 31d1f23302
commit e73131a16a
8 changed files with 111 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
doc/src/sgml/ref/alter_table.sgml
View File

@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.106 2009/05/03 20:45:43 tgl Exp $
$PostgreSQL: pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.107 2009/07/20 02:42:27 adunstan Exp $
PostgreSQL documentation
-->
@ -33,7 +33,7 @@ ALTER TABLE <replaceable class="PARAMETER">name</replaceable>
where <replaceable class="PARAMETER">action</replaceable> is one of:
ADD [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> <replaceable class="PARAMETER">type</replaceable> [ <replaceable class="PARAMETER">column_constraint</replaceable> [ ... ] ]
DROP [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> [ RESTRICT | CASCADE ]
DROP [ COLUMN ] [ IF EXISTS ] <replaceable class="PARAMETER">column</replaceable> [ RESTRICT | CASCADE ]
ALTER [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> [ SET DATA ] TYPE <replaceable class="PARAMETER">type</replaceable> [ USING <replaceable class="PARAMETER">expression</replaceable> ]
ALTER [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> SET DEFAULT <replaceable class="PARAMETER">expression</replaceable>
ALTER [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> DROP DEFAULT
@ -41,7 +41,7 @@ where <replaceable class="PARAMETER">action</replaceable> is one of:
ALTER [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> SET STATISTICS <replaceable class="PARAMETER">integer</replaceable>
ALTER [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }
ADD <replaceable class="PARAMETER">table_constraint</replaceable>
DROP CONSTRAINT <replaceable class="PARAMETER">constraint_name</replaceable> [ RESTRICT | CASCADE ]
DROP CONSTRAINT [ IF EXISTS ] <replaceable class="PARAMETER">constraint_name</replaceable> [ RESTRICT | CASCADE ]
DISABLE TRIGGER [ <replaceable class="PARAMETER">trigger_name</replaceable> | ALL | USER ]
ENABLE TRIGGER [ <replaceable class="PARAMETER">trigger_name</replaceable> | ALL | USER ]
ENABLE REPLICA TRIGGER <replaceable class="PARAMETER">trigger_name</replaceable>
@ -82,7 +82,7 @@ where <replaceable class="PARAMETER">action</replaceable> is one of:
</varlistentry>
<varlistentry>
<term><literal>DROP COLUMN</literal></term>
<term><literal>DROP COLUMN [ IF EXISTS ]</literal></term>
<listitem>
<para>
This form drops a column from a table. Indexes and
@ -90,6 +90,9 @@ where <replaceable class="PARAMETER">action</replaceable> is one of:
dropped as well. You will need to say <literal>CASCADE</> if
anything outside the table depends on the column, for example,
foreign key references or views.
If <literal>IF EXISTS</literal> is specified and the column
does not exist, no error is thrown. In this case a notice
is issued instead.
</para>
</listitem>
</varlistentry>
@ -192,10 +195,12 @@ where <replaceable class="PARAMETER">action</replaceable> is one of:
</varlistentry>
<varlistentry>
<term><literal>DROP CONSTRAINT</literal></term>
<term><literal>DROP CONSTRAINT [ IF EXISTS ]</literal></term>
<listitem>
<para>
This form drops the specified constraint on a table.
If <literal>IF EXISTS</literal> is specified and the constraint
does not exist, no error is thrown. In this case a notice is issued instead.
</para>
</listitem>
</varlistentry>