SELECT
    ps.WeekIncluded AS PaidWeeks,
    PayD.PayDate AS PayDates,
    ps.PayYear AS PYear,
    months.PMonth,
    (SELECT sum(DayPay) FROM Shifts GROUP BY WeekNumber)
FROM dbo.PayStructure ps
JOIN dbo.Months Months
ON ps.MonthID = months.ID
JOIN dbo.PayDates PayD ON ps.MonthID = PayD.MonthID
Group BY ps.MonthID

SELECT
    ps.WeekIncluded AS PaidWeeks,
    PayD.PayDate AS PayDates,
    ps.PayYear AS PYear,
    months.PMonth,
    (SELECT sum(DayPay) FROM Shifts)
FROM dbo.PayStructure ps
JOIN dbo.Months Months
ON ps.MonthID = months.ID
JOIN dbo.PayDates PayD ON ps.MonthID = PayD.MonthID