cannot truncate a table referenced in a foreign key constraint code example

Example 1: cannot truncate a table referenced in a foreign key constraint

SET FOREIGN_KEY_CHECKS = 0; 
TRUNCATE table $table_name; 
SET FOREIGN_KEY_CHECKS = 1;

Example 2: how to force truncate a table in mysql

DELETE FROM mytest.instance;
ALTER TABLE mytest.instance AUTO_INCREMENT = 1;

Example 3: Syntax error or access violation: 1701 Cannot truncate a table referenced in a foreign key constraint

As the error says, you can not truncate tables referenced by foreign keys. 
Delete should work though...

DB::table('some_table')->delete();