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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>6.3. Deleting Data</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 V1.79.1" /><link rel="prev" href="dml-update.html" title="6.2. Updating Data" /><link rel="next" href="dml-returning.html" title="6.4. Returning Data From Modified Rows" /></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">6.3. Deleting Data</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="dml-update.html" title="6.2. Updating Data">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="dml.html" title="Chapter 6. Data Manipulation">Up</a></td><th width="60%" align="center">Chapter 6. Data Manipulation</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 12.4 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="dml-returning.html" title="6.4. Returning Data From Modified Rows">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="DML-DELETE"><div class="titlepage"><div><div><h2 class="title" style="clear: both">6.3. Deleting Data</h2></div></div></div><a id="id-1.5.5.5.2" class="indexterm"></a><a id="id-1.5.5.5.3" class="indexterm"></a><p>
- So far we have explained how to add data to tables and how to
- change data. What remains is to discuss how to remove data that is
- no longer needed. Just as adding data is only possible in whole
- rows, you can only remove entire rows from a table. In the
- previous section we explained that SQL does not provide a way to
- directly address individual rows. Therefore, removing rows can
- only be done by specifying conditions that the rows to be removed
- have to match. If you have a primary key in the table then you can
- specify the exact row. But you can also remove groups of rows
- matching a condition, or you can remove all rows in the table at
- once.
- </p><p>
- You use the <a class="xref" href="sql-delete.html" title="DELETE"><span class="refentrytitle">DELETE</span></a>
- command to remove rows; the syntax is very similar to the
- <code class="command">UPDATE</code> command. For instance, to remove all
- rows from the products table that have a price of 10, use:
- </p><pre class="programlisting">
- DELETE FROM products WHERE price = 10;
- </pre><p>
- </p><p>
- If you simply write:
- </p><pre class="programlisting">
- DELETE FROM products;
- </pre><p>
- then all rows in the table will be deleted! Caveat programmer.
- </p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="dml-update.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="dml.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="dml-returning.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">6.2. Updating Data </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 6.4. Returning Data From Modified Rows</td></tr></table></div></body></html>
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