[SQL]문법정리6(연산함수)

SELECT *
FROM checkins c
limit 10;

select count(*)
from checkins;

SELECT week,
count(*)
FROM checkins c
group by week ;

SELECT *
FROM checkins c;
WHERE week =1 ;

SELECT week,
MIN(likes)
FROM checkins c
group by week ;

SELECT week,
MAX(likes)
FROM checkins c
group by week ;

SELECT week,
AVG(likes)
FROM checkins c
group by week ;

SELECT week,
ROUND(AVG(likes),2)
FROM checkins c
group by week ;

SELECT week,
ROUND(AVG(likes),0)
FROM checkins c
group by week ;

SELECT week,
SUM(likes)
FROM checkins c
group by week ;

SELECT checkin_id,
user_id,
week,
likes
FROM checkins c
WHERE week = 3 ;