Question

sql 使用一条SELECT语句查询一个字段重复而另一个字段不重复的记录

field1 field2
1 11
1 21
2 22
2 22
3 11
3 31
4 41
5 51
5 52
5 53
result:
1
3

Answer 1

select distinct field1 from 表 ta where
exists(select * from 表 tb where ta.field1=tb.field1 and ta.field2<>tb.field2)

Answer 2

Select Distinct(aa),bb From Table
aa不重复，bb可以重复

Answer 3

SELECT t1.field1
FROM (SELECT field1, COUNT(field2) cnt1 FROM tab GROUP BY field1) t1,
(SELECT field1, COUNT(DISTINCT field2) cnt2 FROM tab GROUP BY field1) t2
WHERE t1.field1 = t2.field1 AND t1.cnt1 == t2.cnt2

即可