ERROR 1833 (HY000) - Can't alter a column in MySQL
·Oct 13, 2022·
1 min read
So you came across that error when trying to change the column type in a table because it's used in a foreign key constraint on another MySQL table.
Here's the way to fix it.
set foreign_key_checks=0; ALTER TABLE tablename MODIFY column_name datatype; set foreign_key_checks=1;
Basically, what we are doing here is disabling the foreign key constraint and then re-enabling it once we are done with our alteration.