Fatal error: Uncaught Error: Call to undefined function mysql_connect() in

mysql_connect()这个函数不再使用

 不要修改php.ini文件，改成mysqli_connect()就可以了

全局替换后

报错：Warning: mysqli_error() expects exactly 1 parameter, 0 given in

    $con = mysqli_connect( $dbhost, $dbuser, $dbpass );
    if ( !$con ) {
        die( '数据库链接出错，请检查账号密码及地址是否正确: ' . mysqli_error() );
    }

之前开了数据库端口，重新改为3306后：

原代码：

    $con = mysql_connect( $dbhost, $dbuser, $dbpass );
    if ( !$con ) {
        die( '数据库链接出错，请检查账号密码及地址是否正确: ' . mysql_error() );
    }

    $result = mysql_query('show databases;') or die ( mysql_error() );;
    While($row = mysql_fetch_assoc($result)){       
        $data[] = $row['Database'];
    }
    unset($result, $row);
    if (in_array(strtolower($dbname), $data)){
        mysql_close();
        echo "<script>if(!alert('數據庫已存在')){window.history.back(-1);}</script>";
        exit();
    }

    mysql_query( "CREATE DATABASE $dbname", $con ) or die ( mysql_error() );

修改为

    $con = mysqli_connect( $dbhost, $dbuser, $dbpass );
    if ( !$con ) {
        die( '数据库链接出错，请检查账号密码及地址是否正确: ' . mysqli_error() );
    }

    $result = mysqli_query($con,'show databases;') or die ( mysqli_error($con) );;
    While($row = mysqli_fetch_assoc($result)){
        $data[] = $row['Database'];
    }
    unset($result, $row);
    if (in_array(strtolower($dbname), $data)){
        mysqli_close();
        echo "<script>if(!alert('數據庫已存在')){window.history.back(-1);}</script>";
        exit();
    }

    mysqli_query( $con,"CREATE DATABASE $dbname" ) or die ( mysqli_error($con) );

数据库连接成功