USE tpch1;
DROP TABLE IF EXISTS cs1;
DROP TABLE IF EXISTS cs2;
CREATE TABLE `cs1` (
`t` varchar(2) DEFAULT NULL,
`i` int(11) DEFAULT NULL
) ENGINE=Columnstore;
CREATE TABLE `cs2` (
`t` varchar(2) DEFAULT NULL,
`i` int(11) DEFAULT NULL
) ENGINE=Columnstore;
insert into cs1 values ('MO', 2);
insert into cs1 values (NULL, 2);
select * from cs1 inner join cs2 on (cs1.t = case cs2.t when NULL then 'MO' else cs2.t end);
t	i	t	i
DROP TABLE IF EXISTS cs1;
DROP TABLE IF EXISTS cs2;