query:
	select | select | dml | dml | select | dml | transaction;

dml:
	update | insert ;

select:
	SELECT select_item FROM join WHERE where_cond_2 order_by limit;

order_by:
	| ORDER BY X . field_name;

group_by:
	| GROUP BY X . field_name;

limit:
	LIMIT tinyint_unsigned;

select_item:
	X . field_name  | AVG( X . field_name ) | COUNT( X . field_name) ;

from: 
	table_name AS X | ( select ) AS X;

where_cond_2:
	X . field_name < value;

where_cond_1:
	field_name < value;

insert:
	INSERT INTO table_name ( field_name , field_name ) VALUES ( value , value ) ;

update:
	UPDATE table_name AS X
	SET field_name = value
	WHERE where_cond_2 limit ;

delete:
	DELETE FROM table_name WHERE where_cond_1 limit;

join:
	table_name AS X LEFT JOIN table_name AS Y ON ( X . field_name = Y . field_name ) ;

transaction: start | end;

start: START TRANSACTION;

end: COMMIT | ROLLBACK;

value:
	tinyint_unsigned;

table_name:
	A | B | C | D | E ;

field_name:
	'pk' | 'int_key' | 'int_nokey' ;