快速查询（秋季，春季）

Question

我怎么有一列ID为，列B值=“秋天”或列B值=“春秋”而不是两个表的记录？

谢谢。

Answer 1

尝试此查询

更新的问题 如果只有秋季和字符串值

Select * from atablename where b in ('fall', 'spring') group by a having count(a) = 1 

任何值

Select * from atablename group by a having count(a) = 1 

对于老问题

Select * from atablename where (a = 'Fall' AND b != 'Spring') OR (a != 'Fall' AND b = 'Spring') 

Answer 2

对于原题：

SELECT 
    * 
FROM your_table t 
WHERE ((t.a = 'Fall' AND t.b != 'Spring') OR (t.a != 'Fall' AND t.b = 'Spring')) 

应该做的伎俩

对于新的，

SELECT 
    t.a 
    , t.b 
FROM your_table t 
WHERE ((t.b = 'Fall' AND NOT EXISTS (SELECT * FROM yourtable t1 WHERE t1.a = t.a AND t1.b = 'Spring')) 
    OR (t.b = 'Spring' AND NOT EXISTS (SELECT * FROM yourtable t1 WHERE t1.a = t.a AND t1.b = 'Fall'))) 

应工作