timestamp is not updated on foreign key update

[Hemant Shah]

I am using MYSQL 5.1.38 and I have following tables:

create table table1 (
col1 varchar(50) primary key not null,
ts1 timestamp not null default current_timestamp on update current_timestamp
)engine=innodb;

create table table2 (
col1 varchar(50) not null,
ts2 timestamp not null default current_timestamp on update current_timestamp,
foreign key (col1) references table1 (col1) on update cascade on delete cascade
)engine=innodb;


When I update col1 in table1, the ts1 in table1 and col1 in table2 are updated but ts2 in table2 does not get updated.

Here is the output:


mysql> insert into table1 (col1) values ('test');
Query OK, 1 row affected (0.00 sec)

mysql> insert into table2 (col1) values ('test');
Query OK, 1 row affected (0.00 sec)

mysql> select * from table1;
+------+---------------------+
| col1 | ts1 |
+------+---------------------+
| test | 2013-05-17 09:37:56 |
+------+---------------------+
1 row in set (0.00 sec)

mysql> select * from table2;
+------+---------------------+
| col1 | ts2 |
+------+---------------------+
| test | 2013-05-17 09:38:03 |
+------+---------------------+
1 row in set (0.01 sec)

mysql> update table1 set col1='test1' where col1 = 'test';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0

mysql> select * from table1;
+-------+---------------------+
| col1 | ts1 |
+-------+---------------------+
| test1 | 2013-05-17 09:44:28 |
+-------+---------------------+
1 row in set (0.00 sec)

mysql> select * from table2;
+-------+---------------------+
| col1 | ts2 |
+-------+---------------------+
| test1 | 2013-05-17 09:38:03 |
+-------+---------------------+
1 row in set (0.00 sec)


I would expect ts2 to be updated as well. Is this expected behaviour?