Case - SQL Function

Case {Expression} When {ComparisonExpression} Then {ReturnExpression} Else {ElseExpression} End

Case expressions let you use If...Then...Else logic in SQL Statements.

The database searches for the first instance of {Expression} that is equal to {ComparisonExpression}, and returns the {ReturnExpression}. If no instances of {Expression} matching {ComparisonExpression} are found, the {ElseExpression} is returned.

Case function syntax has these named arguments:

Parameter	Description
Expression	Required. The expression to be searched.
ComparisonExpression	Required. Expression to be searched for in Expression.
ReturnExpression	Required. The expression to be returned if ComparisonExpression is found in Expression.
ElseExpression	Required. Required. The expression to be returned if ComparisonExpression is not found in Expression.

For example:

SELECT CustomerCode,
        Case Category1
        When 'GOLD' Then 'High'
        When 'SILVER' Then 'Medium'
        Else 'Low'
        End
FROM ARCUST