I have formulas for each deduction code so they display as columns.
And the deductions codes are "hard-coded". The end-user needs the ability to select other deduction codes.

NOTE: it needs to display NULL deduction no matter what the user selects.

Not sure how to handle that and still display selected options as columns?

SELECT "PR_PayrollHistoryHeader"."CheckDate", "PR_PayrollHistoryHeader"."CheckNo", "PR_PayrollHistoryHeader"."TotalRegularHours", "PR_PayrollHistoryHeader"."TotalRegularEarnings", "PR_PayrollHistoryDetail"."DeductionCode", "PR_PayrollHistoryDetail"."PayAmt", "PR_PayrollHistoryHeader"."EmployeeKey"

 FROM   "PR_PayrollHistoryDetail" "PR_PayrollHistoryDetail", "PR_PayrollHistoryHeader" "PR_PayrollHistoryHeader"

 WHERE  ((("PR_PayrollHistoryDetail"."EmployeeKey"="PR_PayrollHistoryHeader"."EmployeeKey") AND ("PR_PayrollHistoryDetail"."CheckNo"="PR_PayrollHistoryHeader"."CheckNo")) AND ("PR_PayrollHistoryDetail"."HeaderSeqNo"="PR_PayrollHistoryHeader"."HeaderSeqNo")) AND (("PR_PayrollHistoryDetail"."DeductionCode" IS  NULL ) OR (("PR_PayrollHistoryDetail"."DeductionCode"='000004' OR "PR_PayrollHistoryDetail"."DeductionCode"='000013' OR "PR_PayrollHistoryDetail"."DeductionCode"='000020' OR "PR_PayrollHistoryDetail"."DeductionCode"='000023' OR "PR_PayrollHistoryDetail"."DeductionCode"='KU' OR "PR_PayrollHistoryDetail"."DeductionCode"='RU'))) AND ("PR_PayrollHistoryHeader"."CheckDate">={d '2018-01-01'} AND "PR_PayrollHistoryHeader"."CheckDate"<={d '2018-01-31'})

 ORDER BY "PR_PayrollHistoryHeader"."EmployeeKey", "PR_PayrollHistoryHeader"."CheckDate", "PR_PayrollHistoryHeader"."CheckNo"