MySQL外键约束

Question

I can't figure out this error:

Cannot add or update a child row: a foreign key constraint fails ( freight . rates_detail , CONSTRAINT rates_detail_ibfk_2 FOREIGN KEY ( component_id ) REFERENCES computation ( id ) ON UPDATE CASCADE)

Here's what I'm trying to do(from the log):

INSERT INTO freight.rates_detail(rate_id,component_id,uom,rate,inc_or) values(0821,01,00,011.00,'Y')

I repeatedly looked and looked and reviewed the values of id in table computation and the value in that case: 01 exists.

What's the problem with this?

Answer 1

i just found out that the reference table is MyISAM not InnoDB will it affect?

Yes. As documented under Using FOREIGN KEY Constraints :

The parent and child tables must use the same storage engine.

It goes on to say:

For storage engines that do not support foreign keys (such as MyISAM ), MySQL Server parses and ignores foreign key specifications.