Methods in the wpdb() class should not be called directly. Use the global $wpdb object instead.
$wpdb object can talk to any number of tables but only to one database.(*hyperdb)
Some of the methods in this class require from you to escape all untrusted values you incorporate.
$wpdb -> get_var(‘query’, column_offset, row_offset)
$wpdb -> get_row( ‘query’, output_type, row_offset )
$wpdb -> get_col( ‘query’, column_offset )
$wpdb -> get_results( ‘query’, output_type )
$wpdb -> insert( $table, $data, $format )
$wpdb -> replace( $table, $data, $format )
$wpdb -> update( $table, $data, $where, $format=null, $where_format=null )
$wpdb -> delete( $table, $data, $where_format=null )
$wpdb -> query( ‘query’ )
$wpdb -> get_col_info( ‘type’, offset )
$wpdb -> show_errors()
$wpdb -> hide_errors()
$wpdb -> print_error()
$wpdb -> get_row( ‘query’, output_type, row_offset )
$wpdb -> get_col( ‘query’, column_offset )
$wpdb -> get_results( ‘query’, output_type )
$wpdb -> insert( $table, $data, $format )
$wpdb -> replace( $table, $data, $format )
$wpdb -> update( $table, $data, $where, $format=null, $where_format=null )
$wpdb -> delete( $table, $data, $where_format=null )
$wpdb -> query( ‘query’ )
$wpdb -> get_col_info( ‘type’, offset )
$wpdb -> show_errors()
$wpdb -> hide_errors()
$wpdb -> print_error()
