CREATE TABLE Rota (
    RotaId INT NOT NULL IDENTITY(1, 1) PRIMARY KEY,
    EmployeeId INT NOT NULL FOREIGN KEY REFERENCES Employee(Employee),
    -- Other columns
)

CREATE TABLE EmployeeOvertime (
    EmployeeOvertimeId INT NOT NULL IDENTITY(1, 1) PRIMARY KEY,
    EmployeeId INT NOT NULL FOREIGN KEY REFERENCES Employee(Employee),
    -- Other columns
)

CREATE TABLE RotaOvertime (
    RotaId INT NOT NULL FOREIGN KEY REFERENCES Rota(RotaId),
    EmployeeOvertimeId INT NOT NULL FOREIGN KEY REFERENCES EmployeeOvertime(EmployeeOvertimeId),
    UNIQUE (RotaId, EmployeeOvertimeId)
)