SQL練習(xí)筆記四:連續(xù)出現(xiàn)的數(shù)字
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問(wèn)題:編寫(xiě)一個(gè) SQL 查詢,查找所有至少連續(xù)出現(xiàn)三次的數(shù)字。
CREATE TABLE Log(Id int(4) not null,num int(4) not null);INSERT INTO Log VALUES(1,1);INSERT INTO Log VALUES(2,1);INSERT INTO Log VALUES(3,1);INSERT INTO Log VALUES(4,2);INSERT INTO Log VALUES(5,1);INSERT INTO Log VALUES(6,2);INSERT INTO Log VALUES(7,2);INSERT?INTO?Log?VALUES(8,2);

-- 創(chuàng)建3個(gè)Log表副本L1,L2,L3 通過(guò)Id連續(xù)相比且num相等實(shí)現(xiàn) --SELECT DISTINCTL1.num AS ConsecutiveNumsFROMLog AS L1,Log AS L2,Log AS L3WHEREL1.Id = L2.Id - 1AND L2.Id = L3.Id - 1AND L1.num = L2.numAND L2.num = L3.num;

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