MySQL 5.7 C API Developer Guide
int
mysql_shutdown(MYSQL *mysql,
               enum mysql_enum_shutdown_level shutdown_level)
            mysql_shutdown() is deprecated and will
            be removed in a future version of MySQL. Instead, use
            mysql_real_query() or
            mysql_query() to execute a
            SHUTDOWN statement.
          
          Asks the database server to shut down. The connected user must
          have the SHUTDOWN privilege.
          MySQL servers support only one type of shutdown;
          shutdown_level must be equal to
          SHUTDOWN_DEFAULT. Dynamically linked
          executables that have been compiled with older versions of the
          libmysqlclient headers and call
          mysql_shutdown() must be used
          with the old libmysqlclient dynamic
          library.
        
          An alternative to
          mysql_shutdown() is to use the
          SHUTDOWN SQL statement.
        
The shutdown process is described in The Server Shutdown Process.
Commands were executed in an improper order.
The MySQL server has gone away.
The connection to the server was lost during the query.
An unknown error occurred.