- drop table if exists t1;
- create table t1 (kill_id int);
- insert into t1 values(connection_id());
- select ((@id := kill_id) - kill_id) from t1;
- ((@id := kill_id) - kill_id)
- 0
- kill @id;
- select 1;
- Got one of the listed errors
- select ((@id := kill_id) - kill_id) from t1;
- ((@id := kill_id) - kill_id)
- 0
- select @id != connection_id();
- @id != connection_id()
- 1
- select 4;
- 4
- 4
- drop table t1;