How to use Case Statement

Question

Using C#.Net and MYSQL

I want to use a CASE Statement like SQL

Query

SELECT vehicleno, 
       brandname, 
       CASE 
         WHEN inexpire < 0 THEN 'Expired' 
         ELSE inexpire 
       END AS inexpire 
FROM   (SELECT Concat(plateno, vehicleno)   AS vehicleno, 
               brandname, 
               Datediff(inedate, Curdate()) AS inexpire 
        FROM   tb_car 
        WHERE  inedate < DATE_ADD(Curdate(), INTERVAL 30 DAY) 
        GROUP  BY vehicleno) AS tab1 

When I run the Query it is showing a output as

System.Byte[] instead of Expired

In the above query inexpire is column values

How to solve this issue.....

Need Query Help

Answer 1

IF(inexpire < 0, 'Expired',inexpire) AS inexpire

Answer 2

I think you would need to use the same datatype for both cases

e.g.

case when inexpire < 0 then 'Expired' else 'inexpired' end as inexpire

or

 case when inexpire < 0 then 1 else inexpire end as inexpire

Edit

Actually I just did a quick test on my machine this mixing of datatypes doesn't cause an error but the result just shows as Blob in MySQL Workbench

SELECT  
cast( CASE  WHEN inexpire < 0 THEN 'Expired' ELSE inexpire END as char) as inexpire

stops this issue as suggested here. This should thus avoid the Byte[] issue