You need to stop using reserved words (MONTH, INDICATOR, etc) for
column names:

SELECT sales_month,
SUM(CASE WHEN flag = 0 THEN vague_value ELSE NULL END) AS
foo_tot,
SUM(CASE WHEN flag = 1 THEN vague_value ELSE NULL END) AS
bar_tot,
FROM Foobar;

It is also a bad idea to use proprietary BIT data types to fake
assembly language style programming. SQL is a predicate language;
that is, we discover a fact with a predicate rather than set a flag.