diff options
Diffstat (limited to 'doc/src/sgml/html/tutorial-delete.html')
-rw-r--r-- | doc/src/sgml/html/tutorial-delete.html | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/doc/src/sgml/html/tutorial-delete.html b/doc/src/sgml/html/tutorial-delete.html new file mode 100644 index 0000000..0f89d6b --- /dev/null +++ b/doc/src/sgml/html/tutorial-delete.html @@ -0,0 +1,34 @@ +<?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>2.9. Deletions</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="tutorial-update.html" title="2.8. Updates" /><link rel="next" href="tutorial-advanced.html" title="Chapter 3. Advanced Features" /></head><body id="docContent" class="container-fluid col-10"><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">2.9. Deletions</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="tutorial-update.html" title="2.8. Updates">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="tutorial-sql.html" title="Chapter 2. The SQL Language">Up</a></td><th width="60%" align="center">Chapter 2. The <acronym xmlns="http://www.w3.org/1999/xhtml" class="acronym">SQL</acronym> Language</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 13.4 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="tutorial-advanced.html" title="Chapter 3. Advanced Features">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="TUTORIAL-DELETE"><div class="titlepage"><div><div><h2 class="title" style="clear: both">2.9. Deletions</h2></div></div></div><a id="id-1.4.4.10.2" class="indexterm"></a><p> + Rows can be removed from a table using the <code class="command">DELETE</code> + command. + Suppose you are no longer interested in the weather of Hayward. + Then you can do the following to delete those rows from the table: +</p><pre class="programlisting"> +DELETE FROM weather WHERE city = 'Hayward'; +</pre><p> + + All weather records belonging to Hayward are removed. + +</p><pre class="programlisting"> +SELECT * FROM weather; +</pre><p> + +</p><pre class="screen"> + city | temp_lo | temp_hi | prcp | date +---------------+---------+---------+------+------------ + San Francisco | 46 | 50 | 0.25 | 1994-11-27 + San Francisco | 41 | 55 | 0 | 1994-11-29 +(2 rows) +</pre><p> + </p><p> + One should be wary of statements of the form +</p><pre class="synopsis"> +DELETE FROM <em class="replaceable"><code>tablename</code></em>; +</pre><p> + + Without a qualification, <code class="command">DELETE</code> will + remove <span class="emphasis"><em>all</em></span> rows from the given table, leaving it + empty. The system will not request confirmation before + doing this! + </p></div><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navfooter"><hr></hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="tutorial-update.html" title="2.8. Updates">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="tutorial-sql.html" title="Chapter 2. The SQL Language">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="tutorial-advanced.html" title="Chapter 3. Advanced Features">Next</a></td></tr><tr><td width="40%" align="left" valign="top">2.8. Updates </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 13.4 Documentation">Home</a></td><td width="40%" align="right" valign="top"> Chapter 3. Advanced Features</td></tr></table></div></body></html>
\ No newline at end of file |