tsql - T-sql 中的简单 SUM

Question

这应该很简单。我正在使用 SSMS 2008，试图得到一列的总和。问题是我目前在这一列上分组并且还使用 HAVING 语句。如何获得总记录数 > 1 的总和？这是我目前的 T-SQL 逻辑：

select count(*) as consumer_count from #consumer_initiations
group by consumer
having count(1) > 1

但是这个数据看起来像：

consumer_count 
----------------
2
2
4
3
...

Answer 1

包起来？

SELECT SUM(consumer_count)
FROM (
    select count(*) as consumer_count from #consumer_initiations
    group by consumer
    having count(1) > 1
) AS whatever

Answer 2

使用嵌套查询：

select sum(consumer_count)
FROM (

    select count(*) as consumer_count from #consumer_initiations
    group by consumer
    having count(1) > 1
) as child

Answer 3

select sum(t.consumer_count)
    from (select count(*) as consumer_count 
              from #consumer_initiations
              group by consumer
              having count(1) > 1) t

Answer 4

尝试：

select sum(t.consumer_count) from
(
    select count(*) as consumer_count from #consumer_initiations
    group by consumer
    having count(1) > 1
) t

这将为您提供原始查询返回的记录总和。这些类型的查询称为嵌套查询。

Answer 5

除了包装在另一个查询中，你可以使用这个：

SELECT COUNT(*) AS consumer_count 
FROM #consumer_initiations AS a
WHERE EXISTS
      ( SELECT *
        FROM #consumer_initiations AS b
        WHERE b.consumer = a.consumer
          AND b.PK <> a.PK                -- the Primary Key of the table
      )