GO
ALTER TRIGGER trigger_Checkdate
ON Teacher
AFTER UPDATE
AS
UPDATE Teacher
SET Teacher.FromContract = ins.FromContract,
    Teacher.ToContract = ins.ToContract
    FROM (
    SELECT inserted.TeacherId,
           inserted.FromContract,
           inserted.ToContract
    FROM inserted) ins
    WHERE ins.TeacherId = Teacher.TeacherId AND ins.FromContract = ins.ToContract


UPDATE Teacher
SET FromContract = '12.12.2025',
    ToContract = '12.12.1988'
    Where TeacherId = 26