Applying the MIN aggregate function to a BIT field

Question

I want to write the following query:

SELECT   ..., MIN(SomeBitField), ...
FROM     ...
WHERE    ...
GROUP BY ...

The problem is, SQL Ser

Answer 1

Try the following Note: Min represent And aggregate function , Max represent Or aggregate function

SELECT   ..., MIN(case when SomeBitField=1 then 1 else 0 end), MIN(SomeBitField+0)...
FROM     ...
WHERE    ...
GROUP BY ...

same result

Answer 2

This small piece of code has always worked with me like a charm:

CONVERT(BIT, MIN(CONVERT(INT, BitField))) as BitField

Answer 3

This query is the best solution:

SELECT CASE WHEN MIN(BitField+0) = 1 THEN 'True' ELSE 'False' END AS MyColumn
 FROM MyTable

When you add the BitField+0 it would automatically becomes like int

Answer 4

Since there are only two options for BIT, just use a case statement:

SELECT CASE WHEN EXISTS (SELECT 1 FROM ....) THEN 1 ELSE 0 END AS 'MinBit'
FROM ...
WHERE ...

This has the advantage of:

• Not forcing a table scan (indexes on BIT fields pretty much never get used)
• Short circuiting TWICE (once for EXISTS and again for the CASE)

It is a little more code to write but it shouldn't be terrible. If you have multiple values to check you could always encapsulate your larger result set (with all the JOIN and FILTER criteria) in a CTE at the beginning of the query, then reference that in the CASE statements.

Answer 5

select min(convert(int, somebitfield))

or if you want to keep result as bit

select convert(bit, min(convert(int, somebitfield)))

Answer 6

AVG(CAST(boolean_column AS FLOAT)) OVER(...) AS BOOLEAN_AGGREGATE

Give a fuzzy boolean :

• 1 indicate that's all True;

• 0 indicate that's all false;

• a value between ]0..1[ indicate partial matching and can be some percentage of truth.