LeetCode（数据库）- 好友申请l：总体通过率

--解决方案(1)
WITHt1AS(SELECT1id, COUNT(DISTINCTrequester_id, accepter_id) upFROMRequestAccepted),
t2AS(SELECT1id, COUNT(DISTINCTsender_id, send_to_id) downFROMFriendRequest)
SELECTIF(down=0, 0.00, ROUND(up/down, 2)) accept_rateFROMt1, t2WHEREt1.id=t2.id--解决方案(2)
selectround(
ifnull(
    (selectcount(*) from (selectdistinctrequester_id, accepter_idfromrequest_accepted) asA)
/    (selectcount(*) from (selectdistinctsender_id, send_to_idfromfriend_request) asB),
0)
, 2) asaccept_rate;