Detailed explanation of PHP connection to mysql database test example_PHP tutorial

If you want php to be able to connect to mysql on our homepage, you must know that php needs to enable the mysql module in php.ini. The specific opening method will be introduced later in the article. Let's look at the example test of php connecting to mysql.

PHP connects to the MySQL database through the mysql_connect() function to open a non-persistent MySQL connection.
Grammar:
mysql_connect(servername, username, password);

Parameter description:
servername: optional. The name of the server to be connected, the default is "localhost:3306", generally fill in localhost.
username: optional. The user name used to log in to the database server is usually root.
password: optional. Password to log in to the database server.

Example:

The code is as follows

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代码如下	复制代码
header("Content-type: text/html; charset=utf-8"); $link_id = @mysql_connect('localhost', 'root', '123456789'); if (!$link_id) { die('连接服务器失败'); } if (!@mysql_select_db('web', $link_id)) { die('连接数据库失败'); } if (!@mysql_query("set names 'utf8'", $link_id)) { die('设置utf8格式失败'); } mysql_close(); ?>

header("Content-type: text/html; charset=utf-8");
$link_id = @mysql_connect('localhost', 'root', '123456789');
if (!$link_id) {

Die('Failed to connect to server');

}
if (!@mysql_select_db('web', $link_id)) {

Die('Failed to connect to database');

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$link_id = @mysql_connect('localhost', 'root', '123456789');

}

if (!@mysql_query("set names 'utf8'", $link_id)) {

Die('Failed to set utf8 format');

代码如下	复制代码
if (!$link_id) { die('连接服务器失败'); }

}

mysql_close();

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if (!@mysql_select_db('web', $link_id)) { die('连接数据库失败'); }

?>

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if (!@mysql_query("set names 'utf8'", $link_id)) {     die('设置utf8格式失败'); }

Example analysis: header("Content-type: text/html; charset=utf-8"); Set the page content to html and the page encoding format to utf-8. Ensure that: 1. Database encoding 2. Page encoding 3. Connection encoding are consistent, and there will be no garbled characters.

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$link_id = @mysql_connect('localhost', 'root', '123456789');

Connect to the database, if successful, return a MySQL connection ID to $link_id, otherwise return FALSE. @ means not to output or display database error information to prevent leakage of website privacy.

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if (!$link_id) { Die('Failed to connect to server'); }

Determine whether the connection to the database server is successful. If not, the message "Connection to server failed" will be output and the execution of php will be terminated.

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if (!@mysql_select_db('web', $link_id)) { Die('Failed to connect to database'); }

Determine whether the connection to the server database is successful. If not, the message "Failed to connect to the database" will be output and the execution of php will be terminated.

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if (!@mysql_query("set names 'utf8'", $link_id)) { Die('Failed to set utf8 format'); }

Set the encoding for PHP to connect to the MySQL database. If unsuccessful, the message "Failed to set UTF8 format" will be output and the execution of PHP will be terminated.

Baidu found that the PHP+MYSQL environment is not configured properly, and the default mysql of php5 is closed

The code is as follows

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mysql_close();

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mysql_close();

Release resources, that is: close the database.

Prompts for connecting to mysql database

Running code appears: Call to undefined function 'mysql_connect()'... failed

Copy the php_mysql.dll and libmysql.dll files to c:/winnt/system32 (I missed libmysql.dll)

Find ;extension=php_mysql in php.ini and remove the ";" in front of it Restart the server http://www.bkjia.com/PHPjc/630688.htmlwww.bkjia.comtrue

http: //www.bkjia.com/PHPjc/630688.html

TechArticle

If you want php to be able to connect to mysql on our homepage, you must know that php needs to enable the mysql module in php.ini Yes, the specific opening method will be introduced later in the article. Let’s look at the php connection my...