Php Mysql 简明教程

PHP & MySQL - Database Info Example

MySQL 中有几个重要命令可以在 MySQL 提示符处执行,也可以使用 PHP 等任何脚本来获取有关数据库服务器的各种重要信息。

There are a few important commands in MySQL which can be executed either at the MySQL prompt or by using any script like PHP to get various important information about the database server.

Sr.No.

Command & Description

1

SELECT VERSION( ) Server version string

2

SELECT DATABASE( ) Current database name (empty if none)

3

SELECT USER( ) Current username

4

SHOW STATUS Server status indicators

5

SHOW VARIABLES Server configuration variables

Example

尝试以下示例以获取数据库信息 −

Try the following example to get database info −

将以下示例复制粘贴为 mysql_example.php:

Copy and paste the following example as mysql_example.php −

<html>
   <head>
      <title>Getting MySQL Database Info</title>
   </head>
   <body>
      <?php
         $dbhost = 'localhost';
         $dbuser = 'root';
         $dbpass = 'root@123';
         $dbname = 'TUTORIALS';
         $mysqli = new mysqli($dbhost, $dbuser, $dbpass, $dbname);
         $tutorial_count = null;

         if($mysqli->connect_errno ) {
            printf("Connect failed: %s<br />", $mysqli->connect_error);
            exit();
         }
         printf('Connected successfully.<br />');

         if ($result = mysqli_query($mysqli, "SELECT DATABASE()")) {
            $row = mysqli_fetch_row($result);
            printf("Default database is %s<br />", $row[0]);
            mysqli_free_result($result);
         }
         $mysqli->close();
      ?>
   </body>
</html>

Output

访问部署在 Apache Web 服务器上的 mysql_example.php, 并验证输出。

Access the mysql_example.php deployed on apache web server and verify the output.

Connected successfully.
Default database is tutorials