# A = 1 else 0 if B satisfy two conditions in ms sql server(azure data studio)

## All we need is an easy explanation of the problem, so here it is.

I am trying to get the distinguish column depending on another column’s value.
I was trying to approach with CASE function but could not get exactly what I wanted.

Condition

1. if ColB has only 1 then online
2. if ColB has only 2 then offline
3. if ColB has both 1 and 2 then both
4. if ColB does not have 1 or 2 then none
ColA ColB
A 1
A 2
A 1
B 1
B 1
C 3
D 2
D 2

The result should be like this

ColA distinguish
A both
B online
C none
D offline

Thanks!

## How to solve :

I know you bored from this bug, So we are here to help you! Take a deep breath and look at the explanation of your problem. We have many solutions to this problem, But we recommend you to use the first method because it is tested & true method that will 100% work for you.

### Method 1

Looks like you just need conditional `COUNT`

``````SELECT
t.ColA,
CASE WHEN COUNT(CASE WHEN t.ColB = '1' THEN 1 END) > 0 THEN
CASE WHEN COUNT(CASE WHEN t.ColB = '2' THEN 1 END) > 0 THEN
'both'
ELSE
'online'
END
ELSE
CASE WHEN COUNT(CASE WHEN t.ColB = '2' THEN 1 END) > 0 THEN
'offline'
ELSE
'none'
END
END
FROM YourTable t
GROUP BY
t.ColA;
``````

### Method 2

This is just another way to skin the same cat, using a conditional `COUNT(DISTINCT)` and a conditional `MAX()`:

``````SELECT
ColA
, distinguish =
CASE COUNT(DISTINCT CASE WHEN ColB IN ('1', '2') THEN ColB END)
WHEN 0 THEN 'none'
WHEN 2 THEN 'both'
ELSE
CASE MAX(CASE WHEN ColB IN ('1', '2') THEN ColB END)
WHEN '1' THEN 'online'
ELSE 'offline'
END
END
FROM
dbo.YourTable
GROUP BY
ColA
;
``````

Note: Use and implement method 1 because this method fully tested our system.
Thank you 🙂