(PHP 5 >= 5.0.5, PHP 7) Sets the default client character set

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

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

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

(PHP 5, PHP 7) Selects the default database for database queries

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

(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 thread ID for the current connection

(PHP 5, PHP 7) Set callback function for LOAD DATA LOCAL INFILE command