There are many ways to connect to the mysql database in php. We usually use mysqli_connect, mysql_connect, and mysqli. If you need them, refer to them.
There are many ways to connect to the mysql database in php. We usually use mysqli_connect, mysql_connect, and mysqli. If you need them, refer to them.
1. Use Mysqli to operate Mysql
Example 1. Object oriented style
| The Code is as follows: |
|
$ Mysqli = new mysqli ("localhost", "my_user", "my_password", "world "); /* Check connection */
If (mysqli_connect_errno ()){
Printf ("Connect failed: % sn", mysqli_connect_error ());
Exit ();
} Printf ("Host information: % sn", $ mysqli-> host_info ); /* Close connection */
$ Mysqli-> close ();
?> /**
* The above is a connection with MYSQL.
* Host: the IP address type of the MYSQL host is character type.
* Username: MYSQL logon username type: Login type.
* Passwd: the MYSQL logon password type is confirmed.
* Db: the MYSQL database name type is "Ignore.
* Port: the port number of the MYSQL database.
*/
$ SSQL = "select * from db ";
/* SQL statement to be executed */
$ Query = mysqli_query ($ connect, $ sSQL );
/*
$ Connect: link is the link source.
$ SSQL: query refers to the SQL statement to be executed for a request.
*/
While ($ arr = mysqli_fetch_array ($ query )){
/* $ Query: the result of loop $ query execution */
Print_r ($ arr );
/* Enter the expected field value */
}
Mysqli_free_result ($ query );
/* Release the result set */
Mysqli_close ($ connect );
/* Close the database connection */ |
2. Use Mysql to operate Mysql
In PHP, this task is completed through the mysql_connect () function.
Syntax
Mysql_connect (servername, username, password );
Example
In the following example, we store the connection in a variable ($ con) in the script for later use. If the connection fails, run the "die" section:
| The Code is as follows: |
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$ Con = mysql_connect ("localhost", "peter", "abc123 ");
If (! $ Con)
{
Die ('could not connect: '. mysql_error ());
} // Some code ?> /**
* The above is a connection with MYSQL.
* Host: the IP address type of the MYSQL host is character type.
* Username: MYSQL logon username type: Login type.
* Passwd: the MYSQL logon password type is confirmed.
* Port: the port number of the MYSQL database.
*/
Mysql_select_db ("db ");
/*
Select Database
Database Name
*/
$ SSQL = "select * from db ";
/* SQL query statement */
$ Query = mysql_query ($ sSQL );
/*
$ SSQL: query refers to the SQL statement to be executed for a request.
*/
While ($ arr = mysql_fetch_array ($ query )){
/* $ Query: the result of loop $ query execution */
/* Enter the expected field value */
Print_r ($ arr );
}
Mysql_free_result ($ query );
/* Release the result set */ |
Close connection
When the script ends, the connection is closed. To disable the connection in advance, use the mysql_close () function.
| The Code is as follows: |
|
$ Con = mysql_connect ("localhost", "peter", "abc123 ");
If (! $ Con)
{
Die ('could not connect: '. mysql_error ());
} // Some code Mysql_close ($ con );
?> |
3. Use mysqli in OOP Mode
| The Code is as follows: |
|
$ Conn = new mysqli ("host", "username", "passwd", "db", port );
/**
* The above is a connection with MYSQL.
* Host: the IP address type of the MYSQL host is character type.
* Username: MYSQL logon username type: Login type.
* Passwd: the MYSQL logon password type is confirmed.
* Db: the MYSQL database name type is "Ignore.
* Port: the port number of the MYSQL database.
*/
$ SSQL = "select * from user ";
/* SQL query statement */
$ Query = $ conn-> query ($ sSQL );
/*
$ SSQL: query refers to the SQL statement to be executed for a request.
*/
While ($ arr = $ query-> fetch_array ()){
/* $ Query: the result of loop $ query execution */
Print_r ($ arr );
}
$ Query-> close ();
/* Release the result set */
$ Conn-> close ();
/* Close the database connection */ |
