CODEWITHSUNDEEP
sqlsql-serverlag
kadocolak
kadocolak

Reputation: 25

sql server lag function where condition

In the database, I have +1000,+2000,+3000..... increasing values according to the previous value. These sometimes do not increase, but decrease, I wrote a listing query to find this out.

select NUMBER-lag(NUMBER) over (ORDER BY DATE_TIME) AS 'DIFF' 
from exampleTable with(nolock) 
WHERE CONDITION1='abcdef' AND DATE_TIME >='20220801'

This works and I export to excel and filter and find the ones less than 0, but should I add them directly to the where part in sql?

I tried HAVING because it is a non-normal field, and it didn't work either.

AND (NUMBER-lag(NUMBER) over (ORDER BY DATE_TIME))<0
ORDER BY DATE_TIME ASC

Upvotes: 0

Views: 1158

Answers (1)

Srinivasan Rajasekaran
Srinivasan Rajasekaran

Reputation: 585

So basically it is like this:

;WITH CTE AS (
    SELECT
        NUMBER - LAG(NUMBER) 
            OVER (ORDER BY DATE_TIME) AS 'DIFF'
    FROM exampleTable WITH(NOLOCK)
    WHERE CONDITION1 = 'abcdef'
        AND DATE_TIME >= '20220801'
)
SELECT *
FROM CTE
WHERE DIFF < 0

Upvotes: 1

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