Content Comparison

Mach> create volatile table vtable (id integer primary key, direction varchar(10), refcnt integer);
Created successfully.
Mach> insert into vtable values(1, 'west', 0);
1 row(s) inserted.
Mach> insert into vtable values(2, 'east', 0);
1 row(s) inserted.
Mach> select * from vtable;
ID          DIRECTION   REFCNT      
----------------------------------------
1           west        0           
2           east        0           
[2] row(s) selected.

Mach> insert into vtable values(1, 'west', 0) on duplicate key update set refcnt = 1;

1 row(s) inserted.

Mach> select * from vtable;
ID          DIRECTION   REFCNT      
----------------------------------------
1           west        1           
2           east        0           
[2] row(s) selected.