T-SQL 2005:计算符合条件的所有行和行

下面是场景:

我有一个3列的表:“键列”、“子键列”和“布尔列”,其中前两个是表的主键。

For my query, I'd like to count the number of rows there are for any given value in 'KeyColumn', and I'd also like to know which ones have a value of true for 'BooleanColumn'. My initial thought was to create a query like this:

SELECT
   COUNT(*)
   ,COUNT(CASE WHEN BooleanColumn = 1 THEN 1 ELSE 0 END)
FROM
   MyTable
GROUP BY
   KeyColumn

However, the 2nd part does not work (I'm not entirely sure why I thought it would to begin with). Is it possible to do something like this in one query? Or am I going to need to do multiple queries to make this happen?