SELECT, WHERE, ORDER BY, IFNULL
SELECT, ORDER BY, WHERE, date_format()
SELECT, LEFT JOIN, ON, WHERE
SELECT, WHERE, LIKE와 =
select, is not null, year(), month(), day(), date_format()
select, avg(), round(), as
select, &, sub query
select, inner join, where - with sub query
select, count, distinct, between ~ and ~
in (여러 컬럼)
select, inner join, on, year(), month()
select, group by ( + having), count(*)
select, union, union all, 문자열 비교
select, inner join, group by, having, round, avg
max(), where절에서의 집계함수 사용
distinct, count, is not null
on, is null
sub query, is not null, not in, not exist
group by, sub query, max
case, when, then, datediff
group by, datediff, having
group by, where, count
inner join - on, group by, sum()