Group_Concat in Concat not working with NULL values

Question

I have a table

CREATE TABLE IF NOT EXISTS `dept` (
  `did` int(11) NOT NULL,
  `dname` varchar(50) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

INSE         


        

Answer 1

Hope following query will serve your purpose

SELECT GROUP_CONCAT(
IF(dname IS NOT NULL, CONCAT(did,"','",dname), CONCAT(did,"','NULL")) 
SEPARATOR '),(') AS Result FROM dept