sql mistakes

 UPDATE tbl_WorkFlowMembers

SET Approver_Sequence =

    CASE User_ID

        WHEN 'mtrotter'    THEN 1

        WHEN 'SMIRZA'      THEN 2

        WHEN 'ASAPRA'      THEN 3

        WHEN 'EDIRIX'      THEN 4

        WHEN 'jhoy'        THEN 5

        WHEN 'cwoodhouse'  THEN 6

        WHEN 'SBOISSINOT'  THEN 7

        ELSE Approver_Sequence

    END,

    ModifiedBy = 'pkadma',

    ModifiedOn = GETDATE()

WHERE WorkFlow_ID = 'MSVBH74000027';

here i missed the else condition then remaining record it is updated null in total 13 records.

UPDATE tbl_WorkFlowMembers

SET Approver_Sequence =

    --Approver_Sequence AS CurrentSequence,

    CASE User_ID

        WHEN 'mtrotter'    THEN 1

        WHEN 'SMIRZA'      THEN 2

        WHEN 'ASAPRA'      THEN 3

        WHEN 'EDIRIX'      THEN 4

        WHEN 'jhoy'        THEN 5

        WHEN 'cwoodhouse'  THEN 6

        WHEN 'SBOISSINOT'  THEN 7

        ELSE Approver_Sequence

    END,

  ModifiedBy = 'pkadma',

    ModifiedOn = GETDATE()

WHERE WorkFlow_ID = 'MSVBHSALT027';

COMMIT TRANSACTION;