079 Assignment 13 Answer

SQL

CREATE FUNCTION GetTotalSalesAmount(@productId int)
RETURNS Decimal(18,2)
AS
BEGIN
    DECLARE @totalSales Decimal(18,2)

    select @totalSales = 
    sum(p.Price * ol.Quantity)
    from 
        Products p
        join OrderLines ol on p.ProductId = ol.ProductId
    where p.ProductId = @productId

    RETURN @totalSales
END


select dbo.GetTotalSalesAmount(2)

--manual calc to validate the function
select p.ProductId, p.Price, ol.Quantity
    from 
        Products p
        join OrderLines ol on p.ProductId = ol.ProductId
    where p.ProductId = 2


SELECT 
    p.Name as 'Product Name',
    p.Price,
    c.Name as 'Category Name',
    dbo.GetTotalSalesAmount(p.productId) as 'Total Sales'
FROM
    Products p
    join Categories c on c.CategoryId = p.CategoryId

CREATE PROCEDURE sp_GetProductInfo
    @productId int
AS
BEGIN
    
    SET NOCOUNT ON

    SELECT 
        p.Name as 'Product Name',
        p.Price,
        c.Name as 'Category Name',
        dbo.GetTotalSalesAmount(p.productId) as 'Total Sales'
    FROM
        Products p
        join Categories c on c.CategoryId = p.CategoryId
    WHERE p.ProductId = @productId
END

EXEC sp_GetProductInfo 1
EXEC sp_GetProductInfo @productId = 5