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Editorial Team
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Asked: 2026-06-16T00:56:34+00:00

Is there a viable alternative in T-SQL to a nested IF ELSE for comparisons

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Is there a viable alternative in T-SQL to a nested IF ELSE for comparisons in which different logic must take place based on the result of the comparison? My situation is involves selecting a nvarchar value representing the condition for evaluation, and based on the condition an evaluation takes place. I initially sought to implement this in a CASE statement as follows:

SELECT
            CASE @condition
            WHEN  '<' THEN

                IF (@processing_time < @threshold_value)
                BEGIN
                    SET @condition_met = 1 --compare threshold_value and processing_time
                END

            WHEN '<=' THEN
                    IF (@processing_time <= @threshold_value)
                    BEGIN
                        SET @condition_met = 1 --compare threshold_value and processing_time
                    END
                WHEN '>' THEN
                    IF (@processing_time > @threshold_value)
                    BEGIN
                        SET @condition_met = 1 --compare threshold_value and processing_time
                    END
                WHEN '>=' THEN
                    IF (@processing_time >= @threshold_value)
                    BEGIN
                        SET @condition_met = 1 --compare threshold_value and processing_time
                    END
                WHEN '=' THEN
                    IF (@processing_time = @threshold_value)
                    BEGIN
                        SET @condition_met = 1 --compare threshold_value and processing_time
                    END
            END -- end case statement

However, based on what I have seen elsewhere and the syntax errors I am getting, it seems that the WHEN clause in a case statement can only assign values, not perform evaluation logic. The only alternative I can think of is to perform equivalent logic using nested IF/ELSE statements. IS there a better way? Redesign of tables/data types is an option.

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1 Answer

  1. Editorial Team

    I haven’t got a database here to check this syntax hasn’t got typos in it but this should do it..

    set @condition_met = (SELECT 
                        CASE WHEN (@condition = '<' AND @processing_time < @threshold_value) OR
                                  (@condition = '<=' AND @processing_time <= @threshold_value) OR
                                  (@condition = '>' AND @processing_time > @threshold_value) OR
                                  (@condition = '>=' AND @processing_time >= @threshold_value) OR
                                  (@condition = '=' AND @processing_time = @threshold_value) 
                             THEN 1 ELSE 0 END)

    Alternatively you could simply do a series of IF statements to do the same thing, E.g.

    SET @condition_met = 0;
IF @condition = "<" AND @processing_time < @threshold_value SET @condition_met = 1;
IF @condition = "<=" AND @processing_time <= @threshold_value SET @condition_met = 1;
etc..
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