I've created three tables.

```
CREATE TABLE Clients
(
    ClientID INT IDENTITY(1,1) PRIMARY KEY,
    First_Name VARCHAR(50) NOT NULL,
    Last_Name VARCHAR(50) NOT NULL,
)
CREATE TABLE Reservation
(
    ReservationID INT IDENTITY(1,1) PRIMARY KEY,
    ClientID INT FOREIGN KEY (ClientID) REFERENCES Clients(ClientID),
    Reservation_paid VARCHAR(3) DEFAULT 'NO',
)
CREATE TABLE Payment
(
    Payment_ID INT IDENTITY(1,1) PRIMARY KEY,
    ClientID INT FOREIGN KEY (ClientID) REFERENCES Clients(ClientID),
    ReservationID INT FOREIGN KEY (ReservationID) REFERENCES Reservation(ReservationID),
)

```

I would like to change the value of the column Reservation\_paid to YES at the Reservation table whenever the Client does pay the reservation, and i want to do it automatically with trigger.

Example: If the `ClientID` at the Reservation table exists at the Payment table automatically the value of the Reservation\_paid will set to YES.
Thank you in advance.