-- Migration: Add sub_department_id and activity columns to contractor_rates table
-- Run this if you have an existing database

-- Add sub_department_id column if it doesn't exist
ALTER TABLE contractor_rates 
ADD COLUMN IF NOT EXISTS sub_department_id INT NULL,
ADD COLUMN IF NOT EXISTS activity VARCHAR(200) NULL;

-- Add foreign key constraint for sub_department_id
-- Note: This may fail if the constraint already exists
ALTER TABLE contractor_rates 
ADD CONSTRAINT fk_contractor_rates_sub_department 
FOREIGN KEY (sub_department_id) REFERENCES sub_departments(id) ON DELETE SET NULL;