本节学习下php连接数据库的方法，通过几个例子，来学习如何创建数据库连接，如何打开数据库等。
1，打开一个连接，并选择数据库
<html>
<head>
<title>打开连接并选择数据库-www.jb200.com</title>
</head>
<body>
<?php
$user = "root";
$pass = "123456";
$db = "test_news";
$link = mysql_connect( "192.168.0.10", $user, $pass );
if ( ! $link ){
die( "Couldn't connect to MySQL" );
}
print "Successfully connected to server<P>";
mysql_select_db( $db ) or die ( "Couldn't open $db: ".mysql_error() );
print "Successfully selected database "$db"<P>";
mysql_close( $link );
?>
</body>
</html>
2，连接mysql数据库
<?
$connection = @mysql_connect("192.168.0.10", "test_news", "password") or die(mysql_error());
$dbs = @mysql_list_dbs($connection)or die(mysql_error());
$db_list ="<ul>";
$i =0;
while ($i < mysql_num_rows($dbs)){
$db_names[$i] = mysql_tablename($dbs,$i);
$db_list .= "<li>$db_names[$i]";
$i++;
}
$db_list .="</ul>";
?>
<HTML>
<HEAD>
<TITLE>MySQL Databases</TITLE>
</HEAD>
<BODY>
<P><strong>Databases on localhost</strong>:</P>
<? echo "$db_list"; ?>
</BODY>
</HTML>
3，列出数据库变量信息
<html>
<head>
<title>输出一些mysql数据库信息-www.jb200.com</title>
</head>
<body>
<?php
$user = "root";
$pass = "123456";
$link = mysql_connect( "192.168.0.10", $user, $pass );
if ( ! $link )
die( "Couldn't connect to MySQL" );
$db_res = mysql_list_dbs( $link );
$num = mysql_num_rows( $db_res );
for( $x = 0; $x < $num; $x++ )
print mysql_tablename( $db_res, $x )."<br>";
mysql_close( $link );
?>
</body>
</html>
4，用变更储存mysql连接信息
<?php
//
$hostname="192.168.0.10";
$username="root";
$password="123456";
$dbname="test_news";
$usertable="Employee";
$yourfield = "FirstName";
mysql_connect($hostname,$username, $password) OR DIE ("Unable to connect to database! Please try again later.");
mysql_select_db($dbname);
$query = "SELECT * FROM $usertable";
$result = mysql_query($query);
if($result) {
while($row = mysql_fetch_array($result)){
$name = $row["$yourfield"];
echo "Name: ".$name;
}
}
?>