SQL — Assigning a bit variable in select statement

Question

For example:

declare @bitHaveRows bit
 select @bitHaveRows = count(*)
   from table
  where (predicate)

Are there any functions I can call on this line:

select @bitHaveRows = count(*)

to assign this bit a value of 0 if there are no rows, or 1 if there are one or more rows?

Answer 1

declare @bRowsExist
SELECT @bRowsExist = CAST(count(*) as bit)
FROM yourtable

...not sure if it's a better query than the other suggestions

Answer 2

According to the c onversion chart , there's an implicit conversion from int to bit. But if for some reason that doesn't work:

CASE WHEN COUNT(*) > 0 THEN 1 ELSE 0 END

Answer 3

If your database supports it, you can use a CASE statement:

declare @bitHaveRows
select @bitHaveRows = case when count(*) > 0 then 1 else 0 end
from yourtable