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1. Introduction to PDO
PDO (PHP Data Object) is something added in PHP 5. It is a major new feature added in PHP 5, because before PHP 5, php4/php3 were a bunch of database extensions to communicate with each database. Connection and processing, what php_mysql.dll, php_pgsql.dll, php_mssql.dll, php_sqlite.dll and so on.
PHP6 will also use PDO to connect by default, and the mysql extension will be used as an auxiliary
2. PDO configuration
In PHP.ini, remove the ";" in front of "extension=php_pdo.dll". If you want to connect to the database, also You need to remove the ";" sign in front of the database extension related to PDO, and then restart the Apache server.
extension=php_pdo.dll
extension=php_pdo_mysql.dll
extension=php_pdo_pgsql.dll
extension=php_pdo_sqlite.dll
extension=php_pdo_mssql.dll
extension=php_pdo_odbc.dll
extension=php_ pdo_firebird.dll
......
3. PDO connects to the mysql database
new PDO("mysql:host=localhost;dbname=db_demo","root","");
The default is not a long connection. If you want to use a long connection to the database, you need to add the following parameters at the end:
new PDO("mysql:host=localhost;dbname=db_demo","root","","array(PDO::ATTR_PERSISTENT => true) ");
4. Common PDO methods and their applications
PDO: :query() is mainly used for operations that return recorded results, especially SELECT operations.
PDO::exec() is mainly used for operations that do not return a result set, such as INSERT, UPDATE and other operations.
PDO::lastInsertId() returns In the last insertion operation, the primary key column type is the last auto-incremented ID.
PDOStatement::fetch() is used to get a record.
PDOStatement::fetchAll() is used to get all the record sets into one.
5.PDO operation MYSQL database instance
Copy code The code is as follows:
$pdo = new PDO("mysql:host=localhost;dbname=db_demo","root","");
if ($pdo -> exec("insert into db_demo(name,content) values('title','content')")){
echo "Insertion successful!";
echo $pdo -> lastinsertid();
}
?>
Copy code The code is as follows:
$pdo = new PDO("mysql:host=localhost;dbname=db_demo","root"," ");
$rs = $pdo -> query("select * from test");
while($row = $rs -> fetch()){
print_r($row);
}
?> ;
The above introduces the method of using PDO to connect to the database using jdbc in PHP5, including the content of jdbc connecting to the database. I hope it will be helpful to friends who are interested in PHP tutorials.