ALTER TABLE admissions
    ADD COLUMN bank_payment_method VARCHAR(20) NOT NULL DEFAULT 'bank' AFTER salary_type,
    ADD COLUMN pix_key VARCHAR(190) NULL AFTER bank_account;

UPDATE admissions
SET bank_payment_method = CASE
    WHEN pix_key IS NOT NULL AND TRIM(pix_key) <> '' THEN 'pix'
    ELSE 'bank'
END
WHERE bank_payment_method IS NULL OR bank_payment_method = '';
