Convert CASE expression in SQL to derived column in SSIS [closed]

Answer 1

This is just to show how the expression should be constructed in the derived transformation. I wouldn't suggest doing it this way since it is very hard to maintain.

Refer @billinkc answer to this question Convert CASE expression in SQL to derived column in SSIS

Here is how the expression should be written in Derived transformation.

(FINDSTRING(FixedARMRateReductionLimit,"%",1) > 1) ? ((DT_NUMERIC,5,2)SUBSTRING(FixedARMRateReductionLimit,1,FINDSTRING(FixedARMRateReductionLimit,"%",1) - 1)) : (FixedARMRateReductionLimit == "Weekly PMMS Rate" ? (0.35) : (0.02))

Formatted version of the expression.

(FINDSTRING(FixedARMRateReductionLimit,"%",1) > 1) 
    ?   (
            (DT_NUMERIC,5,2) 
                SUBSTRING(  FixedARMRateReductionLimit, 
                            1, 
                            FINDSTRING(FixedARMRateReductionLimit, "%", 1) - 1
                          )
        ) 
    :   FixedARMRateReductionLimit == "Weekly PMMS Rate" 
            ? (0.35) 
            : (0.02))

Sample data used:

SELECT c1 AS FixedARMRateReductionLimit
FROM
(
            SELECT '2.00%'              AS c1 
    UNION   SELECT '13.95%'             AS c1 
    UNION   SELECT '%52.00%'            AS c1 
    UNION   SELECT '%%'                 AS c1 
    UNION   SELECT '85.%42%'            AS c1 
    UNION   SELECT 'Weekly PMMS Rate'   AS c1 
    UNION   SELECT 'Monthly PMMS Rate' 
) T1

Output of derived transformation when viewed in data viewer: