How can I use SUM for bit columns?

Question

How can use the function SUM() for bit columns in T-SQL?

When I try do it as below:

SELECT SUM(bitColumn) FROM MyTable;

I get the e

Answer 1

You could use SIGN function:

CREATE TABLE tab_x(b BIT);
INSERT INTO tab_x(b) VALUES(1),(0),(0),(NULL),(0),(1);

SELECT SUM(SIGN(b))
FROM tab_x;
-- 2

DBFiddle Demo