php学习笔记(国外英文资料).doc

php学习笔记(国外英文资料) One: use PHP to access the database from the WEB: 1: the basic steps in the WEB query database: A: check and filter the data from the user B: establish a proper database connection C: query the database D: get the query results E: displays the results to the user 1.1: check and filter user data: (1) the trim () function is implemented: Eg: $search = trim ($_POST ( search )) filters the null characters from the $search at the end of the user input; Check for user input: If (! $search | |! $qname) You have not entered search details. Please go back and try again. The exit; (2) when a user independent input data, we want to test the user input data have a special character, so to escape characters, involves the addslashes (), stripslashes (), and functions Get_magic_quotes_gpc (); When the user enters data to a database, the data must be escaped; We first detect that the test has been automatically finished in quotation marks. If you dont have to use the function addslashes () to filter; Eg: if (! Get_magic_quotes_gpc ()) {$searchtype = addslashes ($searchtype); $search = addlashes ($search) } If I take the data from the database, I also filter the backslash using the stripsalshes () function when the magic quotes feature is not open. 1.2: establish a connection: The connection is divided into object-oriented and process-oriented: (1) : @$db = new mysql ( localhost , user name, password, database); This is an object-oriented approach; (2) : @$db = mysql_connect ( localhost , user name, password, database); This is a process oriented approach; This function returns a resource rather than an object, the resource representation to connect to the database, and if you use the process method, the resource must be passed to the mysql all of the other functions; Test connection results: If (mysql_connect_errno ()) { The echo Error: could not connect to database.please try again. The exit; } Mysql has certain restrictions on the number of simultaneous connection