Question

我有一张表如下

select a.studentName,b.courseName 
from tbl_name a 
inner join tbl_name b
on a.courseID = b.courseID

我需要编写一个sql查询，它将遍历表并返回第1列中包含a和b的所有第2列值。

Answer 1

试试这个：

SELECT column2
FROM mytable
WHERE column1 IN ('a', 'b')
GROUP BY column2
HAVING COUNT(DISTINCT column1) = 2

Answer 2

试试这个：

SELECT column1, column2, ROW_NUMBER()OVER(PARTITION BY column1 Order by column1 )as rowCounts  into #tmp2
    FROM #tmp 

SELECT column2 FROM #tmp2 WHERE rowCounts = 1

SQL比较多表中的所有值

2 个答案: