<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >Running SQL Commands</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REV="MADE" HREF="mailto:pgsql-docs@postgresql.org"><LINK REL="HOME" TITLE="PostgreSQL 8.0.11 Documentation" HREF="index.html"><LINK REL="UP" TITLE="ECPG - Embedded SQL in C" HREF="ecpg.html"><LINK REL="PREVIOUS" TITLE="Closing a Connection" HREF="ecpg-disconnect.html"><LINK REL="NEXT" TITLE="Choosing a Connection" HREF="ecpg-set-connection.html"><LINK REL="STYLESHEET" TYPE="text/css" HREF="stylesheet.css"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"><META NAME="creation" CONTENT="2007-02-02T03:57:22"></HEAD ><BODY CLASS="SECT1" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="5" ALIGN="center" VALIGN="bottom" >PostgreSQL 8.0.11 Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="ecpg-disconnect.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="ecpg.html" >Fast Backward</A ></TD ><TD WIDTH="60%" ALIGN="center" VALIGN="bottom" >Chapter 29. <SPAN CLASS="APPLICATION" >ECPG</SPAN > - Embedded <ACRONYM CLASS="ACRONYM" >SQL</ACRONYM > in C</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="top" ><A HREF="ecpg.html" >Fast Forward</A ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="top" ><A HREF="ecpg-set-connection.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="ECPG-COMMANDS" >29.4. Running SQL Commands</A ></H1 ><P > Any SQL command can be run from within an embedded SQL application. Below are some examples of how to do that. </P ><P > Creating a table: </P><PRE CLASS="PROGRAMLISTING" >EXEC SQL CREATE TABLE foo (number integer, ascii char(16)); EXEC SQL CREATE UNIQUE INDEX num1 ON foo(number); EXEC SQL COMMIT;</PRE ><P> </P ><P > Inserting rows: </P><PRE CLASS="PROGRAMLISTING" >EXEC SQL INSERT INTO foo (number, ascii) VALUES (9999, 'doodad'); EXEC SQL COMMIT;</PRE ><P> </P ><P > Deleting rows: </P><PRE CLASS="PROGRAMLISTING" >EXEC SQL DELETE FROM foo WHERE number = 9999; EXEC SQL COMMIT;</PRE ><P> </P ><P > Single-row select: </P><PRE CLASS="PROGRAMLISTING" >EXEC SQL SELECT foo INTO :FooBar FROM table1 WHERE ascii = 'doodad';</PRE ><P> </P ><P > Select using cursors: </P><PRE CLASS="PROGRAMLISTING" >EXEC SQL DECLARE foo_bar CURSOR FOR SELECT number, ascii FROM foo ORDER BY ascii; EXEC SQL OPEN foo_bar; EXEC SQL FETCH foo_bar INTO :FooBar, DooDad; ... EXEC SQL CLOSE foo_bar; EXEC SQL COMMIT;</PRE ><P> </P ><P > Updates: </P><PRE CLASS="PROGRAMLISTING" >EXEC SQL UPDATE foo SET ascii = 'foobar' WHERE number = 9999; EXEC SQL COMMIT;</PRE ><P> </P ><P > The tokens of the form <TT CLASS="LITERAL" >:<TT CLASS="REPLACEABLE" ><I >something</I ></TT ></TT > are <I CLASS="FIRSTTERM" >host variables</I >, that is, they refer to variables in the C program. They are explained in <A HREF="ecpg-variables.html" >Section 29.6</A >. </P ><P > In the default mode, statements are committed only when <TT CLASS="COMMAND" >EXEC SQL COMMIT</TT > is issued. The embedded SQL interface also supports autocommit of transactions (similar to <SPAN CLASS="APPLICATION" >libpq</SPAN > behavior) via the <TT CLASS="OPTION" >-t</TT > command-line option to <TT CLASS="COMMAND" >ecpg</TT > (see below) or via the <TT CLASS="LITERAL" >EXEC SQL SET AUTOCOMMIT TO ON</TT > statement. In autocommit mode, each command is automatically committed unless it is inside an explicit transaction block. This mode can be explicitly turned off using <TT CLASS="LITERAL" >EXEC SQL SET AUTOCOMMIT TO OFF</TT >. </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="ecpg-disconnect.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="ecpg-set-connection.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Closing a Connection</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="ecpg.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Choosing a Connection</TD ></TR ></TABLE ></DIV ></BODY ></HTML >