PHP connection MySQL Database

today learn to connect MySQL database with PHP, write a blog summary.
To use PHP to connect to the MySQL database, we will first connect to the database, we use the following function to connect

$sql _link = mysql_connect ("hostname", "Login username", "Login user name password");

If the connection is successful, a MySQL handle is returned, which can be easily understood as the $sql _link is a bridge between PHP and MySQL, and we can get to MySQL through this bridge.
After entering MySQL, we will select a database to operate on MySQL, we use the following function to select a database

mysql_select_db ("Database name", "This parameter can not");

then we execute some MySQL statements, using the following function

$result = mysql_query ("SQL statement", "This parameter can not be");

when you execute some MySQL statements, there are two things:
1. No results are returned, such as deleting data, modifying the encoding, etc.
2. There are return results, such as querying the data, at which point we use a variable to receive. For example, the following statement, which returns a table, can be seen as a two-dimensional array.

$result = mysql_query ("SELECT * from Person_list", $sql _link);//Returns a resource, currently a table

by $result can know a lot of information about this table, we need to use the corresponding function to get the information we need.
1. This table has several fields.

Mysql_num_fields ($result);

2. The table has several records.

Mysql_num_rows ($result);

3. The field name of this table.

Mysql_field_name ($result, $index);

4. In an indexed array, get the array by one line, and perform a pointer offset once.

Mysql_fetch_row ($result);

5. In the form of an associative array, one-by-one gets the array and executes the pointer offset once.

MYSQL_FETCH_ASSOC ($result);

6. Specify the position of the pointer yourself.

Mysql_data_seek ($result, 3);

7. Sometimes we manipulate the database to determine if there is success by the number of rows affected.

Mysql_affected_rows ();//can have parameters

here is a complete code to demonstrate reading data (the Person_list table under the test database) and displaying it on the page (and not dealing with garbled pages).

<?phpheader (' content-type:text/html; Charset=utf-8 ');//information for the database to be connected define ("Db_host", "localhost");//hostname define (" Db_user "," root ");//Login name define (" Db_user_pwd "," rootmysql ");//login user password//connect to database $sql_link = mysql_connect (db_host,db_ USER,DB_USER_PWD), if ($sql _link)//To determine if the connection is successful echo "Connection database successfully <br/>"; Elseecho mysql_error ($sql _link). " <br/> "; $db _name =" Test ";//which database mysql_select_db to connect to ($db _name, $sql _link); $sql _sentence =" SELECT * FROM Person_ List ";//The SQL statement to execute//$sql _sentence =" desc person_list ";//The SQL statement to execute $result = mysql_query ($sql _sentence, $sql _link);// Returns a resource that is currently a table echo ' <table border= ' 1px "width=" 500px "height=" 400px "> '; Echo ' <tr> '; for ($index = 0; $index & Lt Mysql_num_fields ($result); $index + +) echo ' <td> ' Mysql_field_name ($result, $index). '  </td> '; Echo ' </tr> '; while ($row = Mysql_fetch_row ($result)) {echo ' <tr> '; foreach ($row as $value) echo ' <td> '. $value. ' </td> ';//echo ' <td> '. $value. '  </td> '; Echo ' </tr> ';}Echo ' </table> ';? >

PHP connection MySQL Database