CREATE TABLE operaciya (
	id INT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
	kategoriya_id INT NOT NULL,
	dengohran_izt_id INT NOT NULL,
	dengohran_nazn_id INT,
	summa FLOAT NOT NULL,
	kolichestvo FLOAT,
	polzovatel_id INT NOT NULL,
	data DATE NOT NULL,
	opisanie VARCHAR( 40 ),
	CONSTRAINT fk_operaciya_kategoriya FOREIGN KEY (kategoriya_id)
		REFERENCES kategoriya_operacii (id),
	CONSTRAINT fk_operaciya_dengohran_izt FOREIGN KEY (dengohran_izt_id)
		REFERENCES dengohranilische (id),
	CONSTRAINT fk_operaciya_dengohran_nazn FOREIGN KEY (dengohran_nazn_id)
		REFERENCES dengohranilische (id),
	CONSTRAINT fk_operaciya_polzovatel FOREIGN KEY (polzovatel_id)
		REFERENCES polzovatel (id),
	CONSTRAINT chk_nazn CHECK (
		(((SELECT MAX(deystvie_id) FROM kategoriya_operacii ko WHERE ko.id = kategoriya_id) =  2 ) AND (dengohranilische_nazn_id NOT NULL)) 
		OR
		((SELECT MAX(deystvie_id) FROM kategoriya_operacii ko WHERE ko.id = kategoriya_id) <>  2 )
))

CREATE TRIGGER tg_val BEFORE INSERT ON valuta
	REFERENCING NEW ROW AS new
	FOR EACH ROW WHEN (new.simvol IS NULL)
	SIGNAL SQL_STATE '45000'