Comments on: MySQL’s ERROR 1025 explained

By: Monalisa

Monalisa — Tue, 12 Feb 2008 06:05:50 +0000

Hi All,
Can anybody help me out please?
Can I drop the foreign key and column in separate clauses of one SQL statement?
for example:
ALTER TABLE party
DROP FOREIGN KEY FK_party_advertiser_id,
DROP COLUMN advertiser_id;

Do help please……..
:)

By: Fuvito

Fuvito — Tue, 22 Jan 2008 20:20:21 +0000

Hi All,

I was having the same problem, I was trying to drop a column,

Thanks to Karuna, after reading his reply I noticed: I was trying to drop the index before dropping the foreign key,

Now it works fine with the following order:

SET FOREIGN_KEY_CHECKS = 0;

ALTER TABLE tableX DROP FOREIGN KEY fkId;

ALTER TABLE tableX DROP INDEX idxId;

ALTER TABLE tableX DROP COLUMN columnX;

SET FOREIGN_KEY_CHECKS = 1;

in my case fkId and idxId were same,

Thanks all,

By: Carlos Seo

Carlos Seo — Fri, 04 Jan 2008 12:09:29 +0000

A great solution. I was thinking on delete some tables, change the data column type and create the same tables. I think this is a better solution.

By: Karuna (kgx)

Karuna (kgx) — Mon, 01 Oct 2007 23:19:17 +0000

For those of you still looking for a solution, do this:
> SHOW CREATE TABLE table_name;

That will show the actual constraint name, which may differ from the column name.

Then simply do something like:
> ALTER TABLE table_name DROP FOREIGN KEY xxx_ibfk_d;

Replace ‘xxx_ibfk_d’ with the constraint name that you got above.

HTH :)

By: Xaprb

Xaprb — Wed, 19 Sep 2007 21:49:40 +0000

Ah yes, that’s another gotcha. There’s also another case where it won’t give you more information — in fact, it won’t give you any information — in SHOW INNODB STATUS. You can’t ALTER either the parent or child table to a different storage engine without first dropping the constraint, which as you point out has to be done by constraint name, not index name.

By: Trenton

Trenton — Wed, 19 Sep 2007 21:38:37 +0000

I had a variant of this problem when trying to drop a foreign key column. In my scenario, customer is many-to-one with master_customer, and I wanted to remove master_customer.

This bug/thread http://bugs.mysql.com/bug.php?id=14347 has some info. The short of it is:

1) alter table customer drop foreign key customer_ibfk_1;
2) alter table customer drop column master_customer_id;
3) drop table master_customer;

works for me.

By: nimrod-

nimrod- — Mon, 23 Jul 2007 22:45:58 +0000

i solved this problem by doing it at hand, it is, with other name i create a copy of the table that doesn’t have the definition of the foreign key, then copy all the data in this new table, then delete the old table, and so i couldn’t find a way to rename the new table, create again a table with the original name and place the data in the correct one. then delete the temporal table

By: Xaprb

Xaprb — Tue, 17 Jul 2007 01:50:11 +0000

I’m not sure what Anon meant. If it was a comment about a GUI program, I’m not the one to ask; I do everything from the command-line.

By: Rohitesh

Rohitesh — Mon, 16 Jul 2007 18:50:19 +0000

Anon’s comment helped. Is this a bug???

Cheers,
Rohitesh.

By: Alnoor

Alnoor — Wed, 23 May 2007 18:00:14 +0000

Very Very Informative!