diff options
Diffstat (limited to 'doc/src/sgml/html/dml-delete.html')
-rw-r--r-- | doc/src/sgml/html/dml-delete.html | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/doc/src/sgml/html/dml-delete.html b/doc/src/sgml/html/dml-delete.html new file mode 100644 index 0000000..69c651c --- /dev/null +++ b/doc/src/sgml/html/dml-delete.html @@ -0,0 +1,28 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!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 Vsnapshot" /><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 id="docContent" class="container-fluid col-10"><div 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 15.5 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 /></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 + <a class="xref" href="sql-update.html" title="UPDATE"><span class="refentrytitle">UPDATE</span></a> 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" title="6.2. Updating Data">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="dml.html" title="Chapter 6. Data Manipulation">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="dml-returning.html" title="6.4. Returning Data from Modified Rows">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" title="PostgreSQL 15.5 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 6.4. Returning Data from Modified Rows</td></tr></table></div></body></html>
\ No newline at end of file |