<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >maxdb_select_db</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE="PHP 手册" HREF="index.html"><LINK REL="UP" TITLE="MaxDB PHP Extension" HREF="ref.maxdb.html"><LINK REL="PREVIOUS" TITLE="maxdb_rpl_query_type" HREF="function.maxdb-rpl-query-type.html"><LINK REL="NEXT" TITLE="maxdb_send_long_data" HREF="function.maxdb-send-long-data.html"><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=UTF-8"></HEAD ><BODY CLASS="refentry" 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" >PHP 手册</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="function.maxdb-rpl-query-type.html" ACCESSKEY="P" >上一页</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="function.maxdb-send-long-data.html" ACCESSKEY="N" >下一页</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.maxdb-select-db" ></A >maxdb_select_db</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN112363" ></A ><P > (PECL)</P >maxdb_select_db<P > (no version information, might be only in CVS)</P >maxdb->select_db -- Selects the default database for database queries</DIV ><DIV CLASS="refsect1" ><A NAME="AEN112367" ></A ><H2 >Description</H2 >bool <B CLASS="methodname" >maxdb_select_db</B > ( resource link, string dbname )<BR ></BR ><P > The <B CLASS="function" >maxdb_select_db()</B > function selects the default database (specified by the <CODE CLASS="parameter" >dbname</CODE > parameter) to be used when performing queries against the database connection represented by the <CODE CLASS="parameter" >link</CODE > parameter. </P ><DIV CLASS="note" ><BLOCKQUOTE CLASS="note" ><P ><B >注意: </B > This function should only be used to change the default database for the connection. You can select the default database with 4th parameter in <A HREF="function.maxdb-connect.html" ><B CLASS="function" >maxdb_connect()</B ></A >. </P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN112385" ></A ><H2 >Return values</H2 ><P > 如果成功则返回 <TT CLASS="constant" ><B >TRUE</B ></TT >,失败则返回 <TT CLASS="constant" ><B >FALSE</B ></TT >。 </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN112390" ></A ><H2 >See also</H2 ><P > <A HREF="function.maxdb-connect.html" ><B CLASS="function" >maxdb_connect()</B ></A > <A HREF="function.maxdb-real-connect.html" ><B CLASS="function" >maxdb_real_connect()</B ></A > </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN112395" ></A ><H2 >Example</H2 ><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN112397" ></A ><P ><B >例 1. Object oriented style</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br />$maxdb </font><font color="#007700">= new </font><font color="#0000BB">maxdb</font><font color="#007700">(</font><font color="#DD0000">"localhost"</font><font color="#007700">, </font><font color="#DD0000">"MONA"</font><font color="#007700">, </font><font color="#DD0000">"RED"</font><font color="#007700">, </font><font color="#DD0000">"DEMODB"</font><font color="#007700">);<br /><br /></font><font color="#FF8000">/* check connection */<br /></font><font color="#007700">if (</font><font color="#0000BB">maxdb_connect_errno</font><font color="#007700">()) {<br /> </font><font color="#0000BB">printf</font><font color="#007700">(</font><font color="#DD0000">"Connect failed: %s\n"</font><font color="#007700">, </font><font color="#0000BB">maxdb_connect_error</font><font color="#007700">());<br /> exit();<br />}<br /><br /></font><font color="#FF8000">/* return name of current default database */<br /></font><font color="#007700">if (</font><font color="#0000BB">$result </font><font color="#007700">= </font><font color="#0000BB">$maxdb</font><font color="#007700">-></font><font color="#0000BB">query</font><font color="#007700">(</font><font color="#DD0000">"SELECT SERVERDB FROM USERS WHERE USERNAME='MONA'"</font><font color="#007700">)) {<br /> </font><font color="#0000BB">$row </font><font color="#007700">= </font><font color="#0000BB">$result</font><font color="#007700">-></font><font color="#0000BB">fetch_row</font><font color="#007700">();<br /> </font><font color="#0000BB">printf</font><font color="#007700">(</font><font color="#DD0000">"Default database is %s.\n"</font><font color="#007700">, </font><font color="#0000BB">$row</font><font color="#007700">[</font><font color="#0000BB">0</font><font color="#007700">]);<br /> </font><font color="#0000BB">$result</font><font color="#007700">-></font><font color="#0000BB">close</font><font color="#007700">();<br />}<br /><br /></font><font color="#FF8000">/* change db to non existing db */<br /></font><font color="#0000BB">$maxdb</font><font color="#007700">-></font><font color="#0000BB">select_db</font><font color="#007700">(</font><font color="#DD0000">"XXXXXXXX"</font><font color="#007700">);<br /><br /></font><font color="#FF8000">/* return name of current default database */<br /></font><font color="#007700">if (</font><font color="#0000BB">$result </font><font color="#007700">= </font><font color="#0000BB">$maxdb</font><font color="#007700">-></font><font color="#0000BB">query</font><font color="#007700">(</font><font color="#DD0000">"SELECT SERVERDB FROM USERS WHERE USERNAME='MONA'"</font><font color="#007700">)) {<br /> </font><font color="#0000BB">$row </font><font color="#007700">= </font><font color="#0000BB">$result</font><font color="#007700">-></font><font color="#0000BB">fetch_row</font><font color="#007700">();<br /> </font><font color="#0000BB">printf</font><font color="#007700">(</font><font color="#DD0000">"Default database is %s.\n"</font><font color="#007700">, </font><font color="#0000BB">$row</font><font color="#007700">[</font><font color="#0000BB">0</font><font color="#007700">]);<br /> </font><font color="#0000BB">$result</font><font color="#007700">-></font><font color="#0000BB">close</font><font color="#007700">();<br />}<br /><br /></font><font color="#0000BB">$maxdb</font><font color="#007700">-></font><font color="#0000BB">close</font><font color="#007700">();<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE ><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN112400" ></A ><P ><B >例 2. Procedural style</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br />$link </font><font color="#007700">= </font><font color="#0000BB">maxdb_connect</font><font color="#007700">(</font><font color="#DD0000">"localhost"</font><font color="#007700">, </font><font color="#DD0000">"MONA"</font><font color="#007700">, </font><font color="#DD0000">"RED"</font><font color="#007700">, </font><font color="#DD0000">"DEMODB"</font><font color="#007700">);<br /><br /></font><font color="#FF8000">/* check connection */<br /></font><font color="#007700">if (</font><font color="#0000BB">maxdb_connect_errno</font><font color="#007700">()) {<br /> </font><font color="#0000BB">printf</font><font color="#007700">(</font><font color="#DD0000">"Connect failed: %s\n"</font><font color="#007700">, </font><font color="#0000BB">maxdb_connect_error</font><font color="#007700">());<br /> exit();<br />}<br /><br /></font><font color="#FF8000">/* return name of current default database */<br /></font><font color="#007700">if (</font><font color="#0000BB">$result </font><font color="#007700">= </font><font color="#0000BB">maxdb_query</font><font color="#007700">(</font><font color="#0000BB">$link</font><font color="#007700">, </font><font color="#DD0000">"SELECT SERVERDB FROM USERS WHERE USERNAME='MONA'"</font><font color="#007700">)) {<br /> </font><font color="#0000BB">$row </font><font color="#007700">= </font><font color="#0000BB">maxdb_fetch_row</font><font color="#007700">(</font><font color="#0000BB">$result</font><font color="#007700">);<br /> </font><font color="#0000BB">printf</font><font color="#007700">(</font><font color="#DD0000">"Default database is %s.\n"</font><font color="#007700">, </font><font color="#0000BB">$row</font><font color="#007700">[</font><font color="#0000BB">0</font><font color="#007700">]);<br /> </font><font color="#0000BB">maxdb_free_result</font><font color="#007700">(</font><font color="#0000BB">$result</font><font color="#007700">);<br />}<br /><br /></font><font color="#FF8000">/* change db to non existing db */<br /></font><font color="#0000BB">maxdb_select_db</font><font color="#007700">(</font><font color="#0000BB">$link</font><font color="#007700">, </font><font color="#DD0000">"XXXXXXXX"</font><font color="#007700">);<br /><br /></font><font color="#FF8000">/* return name of current default database */<br /></font><font color="#007700">if (</font><font color="#0000BB">$result </font><font color="#007700">= </font><font color="#0000BB">maxdb_query</font><font color="#007700">(</font><font color="#0000BB">$link</font><font color="#007700">, </font><font color="#DD0000">"SELECT SERVERDB FROM USERS WHERE USERNAME='MONA'"</font><font color="#007700">)) {<br /> </font><font color="#0000BB">$row </font><font color="#007700">= </font><font color="#0000BB">maxdb_fetch_row</font><font color="#007700">(</font><font color="#0000BB">$result</font><font color="#007700">);<br /> </font><font color="#0000BB">printf</font><font color="#007700">(</font><font color="#DD0000">"Default database is %s.\n"</font><font color="#007700">, </font><font color="#0000BB">$row</font><font color="#007700">[</font><font color="#0000BB">0</font><font color="#007700">]);<br /> </font><font color="#0000BB">maxdb_free_result</font><font color="#007700">(</font><font color="#0000BB">$result</font><font color="#007700">);<br />}<br /><br /></font><font color="#0000BB">maxdb_close</font><font color="#007700">(</font><font color="#0000BB">$link</font><font color="#007700">);<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE ><P > The above examples would produce the following output: </P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><PRE CLASS="screen" >Default database is <...>. Warning: maxdb_select_db(): -10709 Connection failed (RTE:database not running) <...> Warning: maxdb_query(): -10821 Session not connected [] <...> Warning: maxdb_close(): -10821 Session not connected [] <...></PRE ></TD ></TR ></TABLE ></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="function.maxdb-rpl-query-type.html" ACCESSKEY="P" >上一页</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >起始页</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="function.maxdb-send-long-data.html" ACCESSKEY="N" >下一页</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >maxdb_rpl_query_type</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="ref.maxdb.html" ACCESSKEY="U" >上一级</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >maxdb_send_long_data</TD ></TR ></TABLE ></DIV ></BODY ></HTML >