relationship tables

st.linux.ily

Now we meet a problem, when we use one of the below:

alter table services
add foreign key (`Customer ID`) references `customer`.`Customer ID` on delete cascade
or
alter table services
add foreign key (`Customer ID`) references customer(`Customer ID`) on delete cascade

we get the error message:

Error Code : 1005
Can't create table '.\pc\#sql-15b0_1.frm' (errno: 150)
(0 ms taken)

any ideas ?

the two tables are:
create table `customer` (
`Customer ID` int(10) not null default `0`,
`Company` varchar(50) default null,
`Email` varchar(50) default null,
primary key (`Customer ID`)
)type=innodb

create table `services` (
`Services ID` int(10) not null default `0`,
`Customer ID` int(10) default null,
`Services Date` timestamp(14) not null,
`Problem` blob,
primary key (`Services ID`),
key `Customer` (`Customer ID`)
)type=innodb