MySQL DELETE FROM WHERE出现的问题

输入DELETE FROM employees WHERE officeCode = 4;时出现的问题

问题一：
Error Code: 1175. You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column. Cannot use range access on index ‘officeCode’ due to type or collation conversion on field ‘officeCode’ To disable safe mode, toggle the option in Preferences -> SQL Editor and reconnect.

解决一：输入set SQL_SAFE_UPDATES = 0;

问题二：
Error Code: 1451. Cannot delete or update a parent row: a foreign key constraint fails (yiibaidb.employees, CONSTRAINT employees_ibfk_1 FOREIGN KEY (reportsTo) REFERENCES employees (employeeNumber))

解决二：输入set FOREIGN_KEY_CHECKS = 0;