Why do I always prompt Calltoundefinedfunctionsqlite_open () when I connect to sqlite using PHP ()

Why do I always prompt Calltoundefinedfunctionsqlite_open () environment win7 + iis when I connect to sqlite using PHP?
In php. ini, open extension = php_pdo_sqlite.dll and extension = php_sqlite3.dll, and restart IIS.
Write $ db = sqlite_open ("test. db") in PHP; always prompt Call to undefined function sqlite_open () why?

Reply to discussion (solution)

Php_sqlite3. only the sqlite3 class is provided, and no discrete functions are provided.
Since you have enabled php_pdo_sqlite, you can use pdo to operate SQLite.

Php_sqlite3. only the sqlite3 class is provided, and no discrete functions are provided.
Since you have enabled php_pdo_sqlite, you can use pdo to operate SQLite.

I finally figured out that I read sqlite2 and previous versions online. the manuals on the official website specifically separated sqlite3 from sqlite.
Thank you, but I still don't quite understand what PDO is.

PDO is a major new feature of PHP 5, because php4/php3 before PHP 5 was a bunch of database extensions to connect to and process various databases, php_mysql.dll, php_pgsql.dll, php_mssql.dll, php_sqlite.dll, and other extensions to connect to MySQL, PostgreSQL, ms SQL Server, and SQLite. Similarly, we must use ADOdb, PEAR: DB, PHPlib :: database abstract classes such as DB are very cumbersome and inefficient to help us. after all, how can we directly use C/C ++ to write php code with a high scaling slope? So, the emergence of PDO is inevitable.