Hi @Omar AbdElhadi ,

check this post for SQL where clause-

https://stackoverflow.com/questions/13469558/case-when-condition-in-where-clause

you can use case in where condition.

Hope this will help you.

regards

Rahul

Hello @Omar AbdElhadi ,

In SQL SERVER – How to use ‘if… else’ in ‘where’ clause 

You can follow this 

https://raresql.com/2013/06/28/sql-server-how-to-use-if-else-in-where-clause/

Hope this link will help you.

Thanks & Regards

Navneet Sharma

Hi Omar,

There's no IF/ELSE in SQL (there is in TSQL, but it can't be used inside SQL statements). For conditions in SELECT output, WHERE clauses etc., you use CASE. There are two variants:

The first:

CASE
  WHEN condition1
    value1
  WHEN condition2
    value2
  ELSE
    value3
  END

So each condition is a full condition like "{MyEntity}.[SomeAttribute] = 'A'". The values are whatever value you need to return.

The second:

CASE variable
  WHEN casevalue1
    value1
  WHEN casevalue2
    value2
  ELSE
    value3
  END

The second variant has a variable/attribute name after the CASE, like "{MyEntity}.[SomeAttribute]" and the value after the WHEN checks the value of that variable/attribute (so like "'A'"). This variant looks more like a traditional case statement in C# etc.

In both cases the number of WHEN statements are variable (at least one, no upper limit), and the ELSE part is optional. Don't forget the END!

A final warning: depending on where you put the CASE statement, the query can become very slow. Especially when you use it in join conditions, or when you add it to a WHEN and the result set isn't already limited a lot, SQL may need to perform full table scans (or full intermediate result set scans), which can hog performance.