One cannot TRUNCATE, MySQL table that has FK constraints applied on it. TRUNCATE is not the same as DELETE. There are 2 possible workarounds for the problem. The good (which does not risk damage to data integrity) and the bad.
- Remove constraints.
- Perform TRUNCATE.
- Delete manually the rows that now have references to nowhere.
- Create constraints.
Option 2: Aka the BAD variant. Very handy during development.
SET FOREIGN_KEY_CHECKS = 0; TRUNCATE table1; TRUNCATE table2; SET FOREIGN_KEY_CHECKS = 1;
Disabling foreign key checks may lead to a damage to the data integrity, for ex. leaving your tables with rows that do not adhere to the FOREIGN KEY constraints.