(PHP 5 >= 5.6.0, PHP 7) Return information about open and cached links

(PHP 5, PHP 7) Returns the version of the MySQL server

(PHP 5, PHP 7) Get the ID generated from the previous INSERT operation

(PHP 5, PHP 7) Changes the user of the specified database connection

(PHP 5, PHP 7) Pings a server connection, or tries to reconnect if the connection has gone down

(PHP 5 >= 5.3.0, PHP 7) Gets a result set from a prepared statement

(PHP 5 >= 5.5.0, PHP 7) Starts a transaction

(PHP 5, PHP 7) Turns on or off auto-committing database modifications

(PHP 5, PHP 7) Returns the MySQL client version as an integer

(PHP 5, PHP 7) Get the number of fields in a result