从几个计数获得总计

Question

我只需要下面添加每个计数的总计，这对我不起作用，我得到＆＃34;关键字附近的语法错误＆＃39; SELECT＆＃39;。＆＃34;：

DECLARE @total int

SET @total = Count(some select statement)

@total = @total + Count(some select statement)
@total = @total + Count(some select statement)
@total = @total + Count(some select statement)
.. and so on

-- now return the grand total
select @total

或者如果您认为有更简单或更有效的方式来做到这一点，我也是全心全意。

Answer 1

declare @total int = 0

select @total += count(*) from (select 1 col1) a
select @total += count(*) from (select 1 col1) a
select @total += count(*) from (select 1 col1) a

select @total