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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>DELETE</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="sql-declare.html" title="DECLARE" /><link rel="next" href="sql-discard.html" title="DISCARD" /></head><body><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">DELETE</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="sql-declare.html" title="DECLARE">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><th width="60%" align="center">SQL Commands</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 11.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="sql-discard.html" title="DISCARD">Next</a></td></tr></table><hr></hr></div><div class="refentry" id="SQL-DELETE"><div class="titlepage"></div><a id="id-1.9.3.100.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">DELETE</span></h2><p>DELETE — delete rows of a table</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">
[ WITH [ RECURSIVE ] <em class="replaceable"><code>with_query</code></em> [, ...] ]
DELETE FROM [ ONLY ] <em class="replaceable"><code>table_name</code></em> [ * ] [ [ AS ] <em class="replaceable"><code>alias</code></em> ]
[ USING <em class="replaceable"><code>using_list</code></em> ]
[ WHERE <em class="replaceable"><code>condition</code></em> | WHERE CURRENT OF <em class="replaceable"><code>cursor_name</code></em> ]
[ RETURNING * | <em class="replaceable"><code>output_expression</code></em> [ [ AS ] <em class="replaceable"><code>output_name</code></em> ] [, ...] ]
</pre></div><div class="refsect1" id="id-1.9.3.100.5"><h2>Description</h2><p>
<code class="command">DELETE</code> deletes rows that satisfy the
<code class="literal">WHERE</code> clause from the specified table. If the
<code class="literal">WHERE</code> clause is absent, the effect is to delete
all rows in the table. The result is a valid, but empty table.
</p><div class="tip"><h3 class="title">Tip</h3><p>
<a class="xref" href="sql-truncate.html" title="TRUNCATE"><span class="refentrytitle">TRUNCATE</span></a> provides a
faster mechanism to remove all rows from a table.
</p></div><p>
There are two ways to delete rows in a table using information
contained in other tables in the database: using sub-selects, or
specifying additional tables in the <code class="literal">USING</code> clause.
Which technique is more appropriate depends on the specific
circumstances.
</p><p>
The optional <code class="literal">RETURNING</code> clause causes <code class="command">DELETE</code>
to compute and return value(s) based on each row actually deleted.
Any expression using the table's columns, and/or columns of other
tables mentioned in <code class="literal">USING</code>, can be computed.
The syntax of the <code class="literal">RETURNING</code> list is identical to that of the
output list of <code class="command">SELECT</code>.
</p><p>
You must have the <code class="literal">DELETE</code> privilege on the table
to delete from it, as well as the <code class="literal">SELECT</code>
privilege for any table in the <code class="literal">USING</code> clause or
whose values are read in the <em class="replaceable"><code>condition</code></em>.
</p></div><div class="refsect1" id="id-1.9.3.100.6"><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="replaceable"><code>with_query</code></em></span></dt><dd><p>
The <code class="literal">WITH</code> clause allows you to specify one or more
subqueries that can be referenced by name in the <code class="command">DELETE</code>
query. See <a class="xref" href="queries-with.html" title="7.8. WITH Queries (Common Table Expressions)">Section 7.8</a> and <a class="xref" href="sql-select.html" title="SELECT"><span class="refentrytitle">SELECT</span></a>
for details.
</p></dd><dt><span class="term"><em class="replaceable"><code>table_name</code></em></span></dt><dd><p>
The name (optionally schema-qualified) of the table to delete rows
from. If <code class="literal">ONLY</code> is specified before the table name,
matching rows are deleted from the named table only. If
<code class="literal">ONLY</code> is not specified, matching rows are also deleted
from any tables inheriting from the named table. Optionally,
<code class="literal">*</code> can be specified after the table name to explicitly
indicate that descendant tables are included.
</p></dd><dt><span class="term"><em class="replaceable"><code>alias</code></em></span></dt><dd><p>
A substitute name for the target table. When an alias is
provided, it completely hides the actual name of the table. For
example, given <code class="literal">DELETE FROM foo AS f</code>, the remainder
of the <code class="command">DELETE</code> statement must refer to this
table as <code class="literal">f</code> not <code class="literal">foo</code>.
</p></dd><dt><span class="term"><em class="replaceable"><code>using_list</code></em></span></dt><dd><p>
A list of table expressions, allowing columns from other tables
to appear in the <code class="literal">WHERE</code> condition. This is similar
to the list of tables that can be specified in the <a class="xref" href="sql-select.html#SQL-FROM" title="FROM Clause"><code class="literal">FROM</code> Clause</a> of a
<code class="command">SELECT</code> statement; for example, an alias for
the table name can be specified. Do not repeat the target table
in the <em class="replaceable"><code>using_list</code></em>,
unless you wish to set up a self-join.
</p></dd><dt><span class="term"><em class="replaceable"><code>condition</code></em></span></dt><dd><p>
An expression that returns a value of type <code class="type">boolean</code>.
Only rows for which this expression returns <code class="literal">true</code>
will be deleted.
</p></dd><dt><span class="term"><em class="replaceable"><code>cursor_name</code></em></span></dt><dd><p>
The name of the cursor to use in a <code class="literal">WHERE CURRENT OF</code>
condition. The row to be deleted is the one most recently fetched
from this cursor. The cursor must be a non-grouping
query on the <code class="command">DELETE</code>'s target table.
Note that <code class="literal">WHERE CURRENT OF</code> cannot be
specified together with a Boolean condition. See
<a class="xref" href="sql-declare.html" title="DECLARE"><span class="refentrytitle">DECLARE</span></a>
for more information about using cursors with
<code class="literal">WHERE CURRENT OF</code>.
</p></dd><dt><span class="term"><em class="replaceable"><code>output_expression</code></em></span></dt><dd><p>
An expression to be computed and returned by the <code class="command">DELETE</code>
command after each row is deleted. The expression can use any
column names of the table named by <em class="replaceable"><code>table_name</code></em>
or table(s) listed in <code class="literal">USING</code>.
Write <code class="literal">*</code> to return all columns.
</p></dd><dt><span class="term"><em class="replaceable"><code>output_name</code></em></span></dt><dd><p>
A name to use for a returned column.
</p></dd></dl></div></div><div class="refsect1" id="id-1.9.3.100.7"><h2>Outputs</h2><p>
On successful completion, a <code class="command">DELETE</code> command returns a command
tag of the form
</p><pre class="screen">
DELETE <em class="replaceable"><code>count</code></em>
</pre><p>
The <em class="replaceable"><code>count</code></em> is the number
of rows deleted. Note that the number may be less than the number of
rows that matched the <em class="replaceable"><code>condition</code></em> when deletes were
suppressed by a <code class="literal">BEFORE DELETE</code> trigger. If <em class="replaceable"><code>count</code></em> is 0, no rows were deleted by
the query (this is not considered an error).
</p><p>
If the <code class="command">DELETE</code> command contains a <code class="literal">RETURNING</code>
clause, the result will be similar to that of a <code class="command">SELECT</code>
statement containing the columns and values defined in the
<code class="literal">RETURNING</code> list, computed over the row(s) deleted by the
command.
</p></div><div class="refsect1" id="id-1.9.3.100.8"><h2>Notes</h2><p>
<span class="productname">PostgreSQL</span> lets you reference columns of
other tables in the <code class="literal">WHERE</code> condition by specifying the
other tables in the <code class="literal">USING</code> clause. For example,
to delete all films produced by a given producer, one can do:
</p><pre class="programlisting">
DELETE FROM films USING producers
WHERE producer_id = producers.id AND producers.name = 'foo';
</pre><p>
What is essentially happening here is a join between <code class="structname">films</code>
and <code class="structname">producers</code>, with all successfully joined
<code class="structname">films</code> rows being marked for deletion.
This syntax is not standard. A more standard way to do it is:
</p><pre class="programlisting">
DELETE FROM films
WHERE producer_id IN (SELECT id FROM producers WHERE name = 'foo');
</pre><p>
In some cases the join style is easier to write or faster to
execute than the sub-select style.
</p></div><div class="refsect1" id="id-1.9.3.100.9"><h2>Examples</h2><p>
Delete all films but musicals:
</p><pre class="programlisting">
DELETE FROM films WHERE kind <> 'Musical';
</pre><p>
</p><p>
Clear the table <code class="literal">films</code>:
</p><pre class="programlisting">
DELETE FROM films;
</pre><p>
</p><p>
Delete completed tasks, returning full details of the deleted rows:
</p><pre class="programlisting">
DELETE FROM tasks WHERE status = 'DONE' RETURNING *;
</pre><p>
</p><p>
Delete the row of <code class="structname">tasks</code> on which the cursor
<code class="literal">c_tasks</code> is currently positioned:
</p><pre class="programlisting">
DELETE FROM tasks WHERE CURRENT OF c_tasks;
</pre></div><div class="refsect1" id="id-1.9.3.100.10"><h2>Compatibility</h2><p>
This command conforms to the <acronym class="acronym">SQL</acronym> standard, except
that the <code class="literal">USING</code> and <code class="literal">RETURNING</code> clauses
are <span class="productname">PostgreSQL</span> extensions, as is the ability
to use <code class="literal">WITH</code> with <code class="command">DELETE</code>.
</p></div><div class="refsect1" id="id-1.9.3.100.11"><h2>See Also</h2><span class="simplelist"><a class="xref" href="sql-truncate.html" title="TRUNCATE"><span class="refentrytitle">TRUNCATE</span></a></span></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="sql-declare.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="sql-commands.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="sql-discard.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">DECLARE </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> DISCARD</td></tr></table></div></body></html>
