我想要只有一个条件的案例陈述的替代

Question

SELECT
    SUBSTR(A.RECORD_KEY,1,10) AS "PRODUCER_TAX_ID",
    CASE 
        WHEN B.SEX_CODE = 'E' THEN TRIM(B.CORPORATE_NAME) 
        ELSE TRIM(B.FIRST_NAME) || TRIM(B.MIDDLE_NAME) || TRIM(B.LAST_NAME) 
    END AS "PRODUCER_NAME",
    SUBSTR(A.RECORD_KEY,11,2) AS "STATE_CODE",  
    CHAR(C.APPT_LOB_EFF_DT) AS "APPOINTMENT_EFFECTIVE_DATE", 
    A.ORIGINATOR_CD AS "USER_ID",
    CASE A.FILE_MAINT_TRX_CD  
        WHEN 'LOBC' THEN 'UPDATE' 
    END AS "TRANSACTION_TYPE"

Answer 1

您可以使用

UNION ALL

如下：

select *, 'UPDATE' AS TRANSACTION_TYPE
from mytable
where FILE_MAINT_TRX_CD = 'LOBC'
UNION ALL
select *, '' AS TRANSACTION_TYPE
from mytable
where FILE_MAINT_TRX_CD <> 'LOBC'