如何以案例陈述最好计算(*)？

Question

以下SQL(在SQL Server上)返回错误:

'*'附近的语法不正确

使用以下SELECT语句是否存在固有的错误？:

SELECT
COUNT(CASE WHEN <conditions> THEN * ELSE NULL END) as conditionalcountall
FROM TABLE

我试过这个变种也失败了:

SELECT
CASE WHEN <conditions> THEN COUNT(*) ELSE NULL END as conditionalcountall
FROM TABLE

Answer 1

我倾向于总和()

SELECT
SUM(CASE WHEN <conditions> THEN 1 ELSE 0 END) as conditionalcountall
FROM TABLE