<HTML ><HEAD ><TITLE >Deletions</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.73 "><LINK REV="MADE" HREF="mailto:pgsql-docs@postgresql.org"><LINK REL="HOME" TITLE="PostgreSQL 7.3.2 Documentation" HREF="index.html"><LINK REL="UP" TITLE="The SQL Language" HREF="tutorial-sql.html"><LINK REL="PREVIOUS" TITLE="Updates" HREF="tutorial-update.html"><LINK REL="NEXT" TITLE="Advanced Features" HREF="tutorial-advanced.html"><LINK REL="STYLESHEET" TYPE="text/css" HREF="stylesheet.css"><META NAME="creation" CONTENT="2003-02-03T20:17:34"></HEAD ><BODY CLASS="SECT1" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >PostgreSQL 7.3.2 Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="tutorial-update.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Chapter 2. The <SPAN CLASS="ACRONYM" >SQL</SPAN > Language</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="tutorial-advanced.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="TUTORIAL-DELETE" >2.9. Deletions</A ></H1 ><A NAME="AEN515" ></A ><P > Suppose you are no longer interested in the weather of Hayward. Then you can do the following to delete those rows from the table. Deletions are performed using the <TT CLASS="COMMAND" >DELETE</TT > command: </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 <TT CLASS="REPLACEABLE" ><I >tablename</I ></TT >;</PRE ><P> Without a qualification, <TT CLASS="COMMAND" >DELETE</TT > will remove <SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >all</I ></SPAN > rows from the given table, leaving it empty. The system will not request confirmation before doing this! </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="tutorial-update.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="tutorial-advanced.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Updates</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="tutorial-sql.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Advanced Features</TD ></TR ></TABLE ></DIV ></BODY ></HTML >