how to modify the foreign key column name and how to drop foreign key in Mysql

Question

how to modify the foreign key column name and how to drop foreign key in Mysql when we drop than Error 150 comes and when modify or rename than error 152 comes

Answer 1

while trying to drop a foreign key, use the constraint name rather than the column name of the foreign key

ALTER TABLE `table_name` DROP FOREIGN KEY `id_name_fk`

and

ALTER TABLE `thetable`
  DROP KEY `oldkey`, 
  ADD KEY `newkey` (`tablefield`);

or

ALTER TABLE table_name
DROP FOREIGN KEY 'table_name_consraint',
ADD CONSTRAINT `fk_table_name_consraint` FOREIGN KEY (`column`) REFERENCES `table_name` (`column`);