-- Add taxable flag to salary scale components (like allowance_types).
-- When taxable = 0, the component is still paid but not included in the PAYE chargeable income.
USE university_payroll;

ALTER TABLE salary_scale_components
ADD COLUMN taxable TINYINT(1) NOT NULL DEFAULT 1
COMMENT '1 = include in tax base, 0 = non-taxable (like some allowances)'
AFTER amount;
