---

-- Таблица 1: t1
CREATE TABLE t1 (
    id SERIAL PRIMARY KEY,
    name VARCHAR(10) UNIQUE,
    val INT CHECK (val > 10 AND val < 20)
);

-- Таблица 2: t2
CREATE TABLE t2 (
    id SERIAL PRIMARY KEY,
    name VARCHAR(10),
    val INT,
    FOREIGN KEY (val) REFERENCES t1(id)
);