案例选择另一列AS400查询

Question

I have simple query which is not working:

SELECT BATCH_0002.CREATOR, BATCH_0002.GLEXR,
case when BATCH_0002.GLIVD >'0' THEN BATCH_0002.GLIVD ELSE BATCH_0002.date end 
as tarih FROM BATCH_0002

Error is:

ERROR: [IBM][System i Access ODBC Driver][DB2 for i5/OS]SQL0581 - The results in a CASE expression are not compatible. Error Code: -581

but when I change column name to something different than GLIVD , it is working.

SELECT BATCH_0002.CREATOR, BATCH_0002.GLEXR,
case when BATCH_0002.GLIVD >'0' THEN BATCH_0002.GLEXR ELSE BATCH_0002.date end 
as tarih FROM BATCH_0002

Is there something wrong with my case statement?

Answer 1

In Case statement result datatype should be same. Here Using int and date as result in case that's why error showing for incompatible data

you should cast one datatype to another

SELECT BATCH_0002.CREATOR, BATCH_0002.GLEXR, case when BATCH_0002.GLIVD >'0' THEN cast(BATCH_0002.GLIVD as char) ELSE cast(BATCH_0002.date as char) end as tarih FROM BATCH_0002

Answer 2

thank you for all answers regarding data types. worked on this information and now solved, this works very well:

    SELECT BATCH_0002.CREATOR, BATCH_0002.GLEXR, 
    case when BATCH_0002.GLIVD >'0' THEN 
    DATE(CHAR(1900000 + BATCH_0002.GLIVD)) 
    ELSE BATCH_0002.date end as tarih FROM BATCH_0002