Mariadb 简明教程

MariaDB - Connection

与 MariaDB 建立连接的一种方法是使用命令提示符中的 mysql 二进制文件。

One way to establish a connection with MariaDB consists of using the mysql binary at the command prompt.

MYSQL Binary

查看下面给出的示例。

Review an example given below.

[root@host]# mysql -u root -p

Enter password:******

上面给出的代码连接到 MariaDB 并提供用于执行 SQL 命令的命令提示符。输入代码后，会显示一条欢迎消息，表明连接成功，并显示版本号。

The code given above connects to MariaDB and provides a command prompt for executing SQL commands. After entering the code, a welcome message should appear indicating a successful connection, with the version number displayed.

Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 122323232
Server version: 5.5.40-MariaDB-log

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>

该示例使用 root 访问，但具有权限的任何用户当然都可以访问 MariaDB 提示并执行操作。

The example uses root access, but any user with privileges can of course access the MariaDB prompt and perform operations.

通过 exit 命令断开与 MariaDB 的连接，如下所示：

Disconnect from MariaDB through the exit command as follows −

mysql> exit

PHP Connection Script

连接到 MariaDB 并断开连接的另一种方法是使用 PHP 脚本。PHP 提供 mysql_connect() 函数用于打开数据库连接。它使用五个可选参数，并在连接成功后返回 MariaDB 链接标识符，或在连接不成功时返回 false。它还提供了 mysql_close() 函数用于关闭数据库连接，该函数使用单个参数。

Another way to connect to and disconnect from MariaDB consists of employing a PHP script. PHP provides the mysql_connect() function for opening a database connection. It uses five optional parameters, and returns a MariaDB link identifier after a successful connection, or a false on unsuccessful connection. It also provides the mysql_close() function for closing database connections, which uses a single parameter.

Syntax

审阅以下 PHP 连接脚本语法 −

Review the following PHP connection script syntax −

connection mysql_connect(server,user,passwd,new_link,client_flag);

参数说明如下 −

The description of the parameters is given below −

Sr.No	Parameter & Description
1	server This optional parameter specifies the host name running the database server. Its default value is “localhost:.3036.”
2	user This optional parameter specifies the username accessing the database. Its default value is the owner of the server.
3	passwd This optional parameter specifies the user’s password. Its default value is blank.
4	new_link This optional parameter specifies that on a second call to mysql_connect() with identical arguments, rather than a new connection, the identifier of the current connection will be returned.
5	client flags This optional parameter uses a combination of the following constant values − MYSQL_CLIENT_SSL − It uses ssl encryption. MYSQL_CLIENT_COMPRESS − It uses compression protocol. MYSQL_CLIENT_IGNORE_SPACE − It permits space after function names. MYSQL_CLIENT_INTERACTIVE − It permits interactive timeout seconds of inactivity prior to closing the connection.

审阅下面给出的 PHP 断开连接脚本语法 −

Review the PHP disconnection script syntax given below −

bool mysql_close ( resource $link_identifier );

如果您省略资源，最近打开的资源将关闭。它在成功关闭时返回 true 值，或者在失败时返回 false 值。

If you omit the resource, the most recent opened resource will close. It returns a value of true on a successful close, or false.

尝试以下示例代码以连接至 MariaDB 服务器 −

Try the following example code to connect with a MariaDB server −

<html>
   <head>
      <title>Connect to MariaDB Server</title>
   </head>

   <body>
      <?php
         $dbhost = 'localhost:3036';
         $dbuser = 'guest1';
         $dbpass = 'guest1a';
         $conn = mysql_connect($dbhost, $dbuser, $dbpass);

         if(! $conn ) {
            die('Could not connect: ' . mysql_error());
         }

         echo 'Connected successfully';
         mysql_close($conn);
      ?>
   </body>
</html>

成功连接后，您将看到以下输出 −

On successful connection, you will see the following output −

mysql> Connected successfully