Mysql delete foreign key constraint

Usually there are two related tables, and we will carry out primary and foreign key constraints. But sometimes we may need to remove the primary and foreign key constraints. Below I will tell you how to remove the primary and foreign key constraints.

note is a table with foreign key constraints

show create table note;

After execution, the code similar to the following will appear,

Note_ibfk_1 and note_ibfk_2 here are the foreign key names of constraints.

  CONSTRAINT `note_ibfk_1` FOREIGN KEY (`uid`) REFERENCES `user` (`uid`),
  CONSTRAINT `note_ibfk_2` FOREIGN KEY (`ncid`) REFERENCES `noteclassification` (`ncid`)

Execute the following code, the foreign key is released successfully. (my table name is note)

alter table note drop foreign key note_ibfk_2;