摘要：
1. 在表中找出指定字段重复记录个数 答案：SELECT [Field1],[Field2],[Field3],[...],COUNT(*) FROM [TableName] WHERE[Condition] GROUPBY [Field1],[Field2],[Field3],[...]HAVING COUNT(*)>12. 表中每个Y的最新X(ID为主健且自增) 答案：SELECTID,Y,X FROM TableName T WHERE (NOTEXISTS(SELECT 1FROM TableName T2 WHERE (T2.Y=T.Y)AND(T2.X>T.XOR T2 阅读全文