Hi everyone. I need to drop a foreign key constraint from a table (or
add an "ON DELETE SET DEFAULT") but the constraint is unnamed. Is
there anyway to do that? I looked online but didn't find anything.
-Brandon
Brandon wrote:
> Hi everyone. I need to drop a foreign key constraint from a table (or
> add an "ON DELETE SET DEFAULT") but the constraint is unnamed. Is
> there anyway to do that? I looked online but didn't find anything.
Use "SHOW CREATE TABLE tablename". It'll show you the constraint name,
which was generated automatically by MySQL when you declared the foreign
key.
Example:
create table prim (i int primary key);
create table fore (i int, foreign key (i) references prim(i));
show create table fore;
CREATE TABLE `fore` (
`i` int(11) default NULL,
KEY `i` (`i`),
CONSTRAINT `fore_ibfk_1` FOREIGN KEY (`i`) REFERENCES `prim` (`i`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1
Regards,
Bill K.
> > Hi everyone. I need to drop a foreign key constraint from a table (or
> > add an "ON DELETE SET DEFAULT") but the constraint is unnamed. Is
> > there anyway to do that? I looked online but didn't find anything.
>
> Use "SHOW CREATE TABLE tablename". It'll show you the constraint name,
> which was generated automatically by MySQL when you declared the foreign
> key.
>
>
Actually, I tried that and it still didn't show an identifier.
Brandon wrote:
>> Use "SHOW CREATE TABLE tablename". It'll show you the constraint name,
>
> Actually, I tried that and it still didn't show an identifier.
This may be dependent on the version of MySQL you use. I tested the
example I gave, using MySQL 5.0.24. What version are you using?
Regards,
Bill K.