用于查找两个表之间的匹配记录组的 SQL 查询

Question

假设我有两张桌子：

Table "Shares":

+---------+
| share 1 |
+---------+
| share 2 |
+---------+

And table "Valuations"

+-------------+---------+
| valuation 1 | Share 1 |
+-------------+---------+
| valuation 1 | Share 2 |
+-------------+---------+
| valuation 2 | Share 1 |
+-------------+---------+
| valuation 3 | Share 1 |
+-------------+---------+
| valuation 3 | Share 2 |
+-------------+---------+

我想知道是否有一个 SQL Server (T-SQL) 查询从“Shares”表开始并仅返回包含“share”记录（“Share 1”和“Share 2”）的那些估值") - 两个表之间的内部连接也会在结果集中返回“值 2”，这不是我想要的。

任何帮助将不胜感激，

谢谢

Answer 1

假设shares和valuations中的列名是share，可以按估值分组并在having子句中设置条件：

select valuation
from valuations
group by valuation
having count(distinct share) = (select count(*) from shares)

如果您想要评估中的所有行：

select * from valuations
where valuation in (
  select valuation
  from valuations
  group by valuation
  having count(distinct share) = (select count(*) from shares)
)

请参阅demo。