Skip to content

Instantly share code, notes, and snippets.

What would you like to do?
Truncate tables with foreign key constraints in a Laravel seed file.

For the scenario, imagine posts has a foreign key user_id referencing

public function up()
	Schema::create('posts', function(Blueprint $table) {

running seeds with truncate() will trigger a constraint violation if foreign key checks is not disabled.

	Syntax error or access violation: 1701 Cannot truncate a table referenced in a foreign key constraint ...

The fix:


class DatabaseSeeder extends Seeder {

	 * Run the database seeds.
	 * @return void
	public function run()

		//disable foreign key check for this connection before running seeders
		DB::statement('SET FOREIGN_KEY_CHECKS=0;');

		// supposed to only apply to a single connection and reset it's self
		// but I like to explicitly undo what I've done for clarity
		DB::statement('SET FOREIGN_KEY_CHECKS=1;');


fix from here

As pointed out in the comments at SO you wouldn't want to disable foreign key checks on a production app but you really don't want to run seed files in production either so obviously this is not intended for production but helpful in development.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment