问题1:UPDATE TABLE_A AS A LEFT JOIN TABLE_B AS B ON A.ID = B.ID SET A.SCORE = B.SCORE
问题2:SELECT * FROM (SELECT D.*, (COUNT(BID) = (SELECT COUNT(ID) FROM C)) AS ZT FROM D GROUP BY BID) AS T WHERE T.ZT = 1 这个sql能查出选了全部课程的学生
问题2:SELECT * FROM (SELECT D.*, (COUNT(BID) = (SELECT COUNT(ID) FROM C)) AS ZT FROM D GROUP BY BID) AS T WHERE T.ZT = 1 这个sql能查出选了全部课程的学生
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