问题
Here's a print of my error:
mysql> ALTER TABLE Price DROP FOREIGN KEY Id
ERROR 1025 (HY000): Error on rename of '.\testdb\Price' to '.\t
estdb\#sql2-bcc-16' (errno: 152)
I've read this page which suggests that the problem may be due to a left-over table from some earlier alter table error, and recommends you snoop around in your data directory and delete any table with a name such as 'B-xxx.frm'.
My error is similar to this, but there is no '#sql2-bcc-16' in my data directory. And there wouldn't be any artifacts of a previous failed alter table, anyway, because this is just a small test database and I haven't actually altered any tables previously.
EDIT: More info below.
What I really want to do is change an Id (primary key) in another table to be a SMALLINT (instead of a TINYINT). However, THIS Phone table's Id is a foreign key, referencing Id in the other table. So, I believe I need to drop the foreign key of this table before proceeding with the type-change in the primary table. I hope this is clear.
EDIT 2: Tables.
Sale - has Id TINYINT NOT NULL, PRIMARY KEY (Id)
Phone - has Id TINYINT NOT NULL, FOREIGN KEY (Id) REFERENCES Sale (Id)
I would like all Ids in my database to be SMALLINT and not TINYINT. That's my current situation.
回答1:
try with mysql> ALTER TABLE Price DROP Id
Hope it works... Good Luck
I tried with you query mysql> ALTER TABLE Price DROP FOREIGN KEY Id
It executes, but didn't worked!!!
Update:
Use below queries...
mysql> ALTER TABLE Price MODIFY Id SMALLINT
mysql> ALTER TABLE Sale MODIFY Id SMALLINT
mysql> ALTER TABLE Phone MODIFY Id SMALLINT
来源：https://stackoverflow.com/questions/8905856/mysql-alter-table-generating-error-on-rename