原生mysql查询,选择数据库,建立连接及查询数据表PHP完整流程

用mysqli_connect,mysql_connect,mysqli_select_db,mysql_select_db

,mysqli_query,mysql_query直接选择数据库.数据表并进行查询完整代码

database.php文件为数据库的用户或密码等

<?php

return array (
'default' => array (
'hostname' => '127.0.0.1',
'database' => 'phpcms',
'username' => 'root',
'password' => 'root',
'tablepre' => 'v9_',
'charset' => 'utf8',
'type' => 'mysql',
'debug' => true,
'pconnect' => 0,
'autoconnect' => 0
),
);

?>

$mysql_user=include(PHPS_PATH.'/caches/configs/database.php');//得到数据库配置
$username=$mysql_user['default']['username'];
$password=$mysql_user['default']['password'];
$tablepre=$mysql_user['default']['tablepre'];
$database=$mysql_user['default']['database'];

$con = mysqli_connect($mysql_user['default']['hostname'],$username,$password);//句柄

mysqli_select_db($con,$database);//选择数据库
$sql = ' SELECT * FROM '.$tablepre."pay_account where trade_sn='".$out_trade_no."'";
//file_put_contents('3.txt',$sql);
$result2=mysqli_query($con,$sql);
$orderinfo=mysqli_fetch_array($result2);;
$uid=$orderinfo['userid'];
//更新数据库
$sql4 = ' update  '.$tablepre."pay_account set status= 'succ'  where userid=".$uid ." and trade_sn='".$out_trade_no."'";
$result4=mysqli_query($con,$sql4);
mysqli_close($con);