Postgres 10

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CREATE TABLE salary
(
  employee_id integer NOT NULL,
  salary_data integer NOT NULL,
  salary_date date NOT NULL
);

CREATE TABLE EMPLOYEE
(
  employee_id integer NOT NULL UNIQUE
);
ALTER TABLE salary ALTER COLUMN salary_date SET DEFAULT current_date;
ALTER TABLE salary
ADD CONSTRAINT FK_Salary_Employee_ID FOREIGN KEY(employee_id)
REFERENCES EMPLOYEE(employee_id)
ON UPDATE CASCADE
ON DELETE CASCADE
;