--purge-with-truncate option fails

[Gawel1]

When i try to purge data with purge-with-truncate option before insert fixtures, i have a SQL error :

[Doctrine\DBAL\DBALException]                                                                                                                                                                                                             
  An exception occurred while executing 'TRUNCATE table':                                                                                                                                                                      

  SQLSTATE[42000]: Syntax error or access violation: 1701 Cannot truncate a table referenced in a foreign key constraint (`database`.`table`, CONSTRAINT `FK_E75F52F596D36FD` FOREIGN KEY (`foreign_key`) REFE  
  RENCES `database`.`table2` (`id`))                  

[Ocramius]

This is pretty much normal if you didn't correctly setup cascade operations.

[Gawel1]

Are you sure? My DB is mysql 5.5 and it appears it can't truncate tables with foreign keys...
I made a cascade "all" in my entity for my relation and the error still exist.

This is the mySQL documentation : TRUNCATE TABLE fails for an InnoDB table if there are any FOREIGN KEY constraints from other tables that reference the table. Foreign key constraints between columns of the same table are permitted.

[Ocramius]

Did you also set onDelete? Seems also like a MySQL bug to me, why the heck would they implement it like that?

[Gawel1]

Yes, i tried to add onDelete="CASCADE" on my entity property and i had the same issue.
It appears this is a new security since mysql 5.5 which can be disabled with the following workaround :

SET FOREIGN_KEY_CHECKS=0; TRUNCATE table1; SET FOREIGN_KEY_CHECKS=1;

Do you think that could be used?

[Ocramius]

@Gawel1 that is a quite bad idea and can lead to FK constraint inconsistencies.

I'll redirect you to doctrine/data-fixtures#17, since the module here simply pushes the flags one level down to data-fixtures