#1025 - Error on rename (errno: 150) in mysql

Question

I am trying to drop a foreign key(id) in one table(misc) which is the primary key(id) in table(main). db name(xxx)

alter table misc drop FOREIGN KEY id
         


        

Answer 1

In my case, was necessary to make a 3-step process (my table is named "articulos", and the hard-to-remove index is "FK_Departamento_ID")

1. For knowing the name of table, I executed:

   SHOW INDEX FROM articulos;
   

2. This statement resolved the issue (#1025, errno: 150), but the index remained in the table

   ALTER TABLE articulos DROP FOREIGN KEY FK_Departamento_ID;
   

3. The following statement finally wiped out the index

   DROP INDEX FK_Departamento_ID ON articulos;