Question

I am trying to do rather complex SQL query to produce a report. This is a database used by an inventory and accounting system.

Essentially I need to produce a report with the following columns

• Month / Year (group results by month / year)
• Reseller (order results by reseller with in the month / year group)
• Total sales – Sales – Hardware
• Total sales – Sales – Consumables

The following tables will need to be used in the report:

• Invoice
• Reseller
• Job
• JobStockItem
• Stock

Essentially the query would need to start as:
1. Select all invoices from Invoice
2. Get the reseller name from Reseller.Name (join on Reseller.ID with Invoice.CustomerID)
3. Get the associated job ID from Job table (join on Job.InvoiceID with Invoice.ID)
4. Get each component of the invoice from JobStockItems (join JobStockItem.JobID on Job.ID)
5. Get the stock item in in the job from Stock (join on JobStockItems.StockId on Stock.ID) and see if the category (Stock.Category1) is either Hardware or Consumables
6. If the stock item is hardware or consumables, use the sale price in the JobStockItem (JobStockItem.PriceExTax) and add it towards the total for the month of the resellers purchases

The month and year come from the invoice date (Invoice.InvoiceDate).

Now I could produce this result myself by executing a bunch of queries and processing myself, one each for the above steps, but it’s going to end up slow and I’m sure there’d have to be a query out there that could wrap all those requirements up and do it in one?

I have not attempted to do the query yet as to be honest, I don’t know where to start – it’s a lot more complex than anything I’ve done in the past.

I am just using Management Studio, not using Reporting Services, Crystal Reports or anything. My aim is to dump the output to HTML when I have it working.

Thanks heaps in advance.

Answer 1

It think if you Left Join into the JobStockItems table twice (once for hardware, and once for consumables), you can manage all that in one query. The final query will look something like this (Don’t have my editor up right now, so apologies for any typos)

SELECT DATEPART(m, Invoice.InvoiceDate) month, 
       DATEPART(yy, Invoice.InvoiceDate) year, 
       Reseller.Name, 
       SUM(jobstockitems_hardware.Price) sales_hardware,
       SUM(jobstockitems_consumables.Price) sales_consumables, 
FROM Invoice
INNER JOIN Reseller
ON Invoice.CustomerID = Reseller.ID
INNER JOIN Job
ON Invoice.ID = Job.InvoiceID
LEFT JOIN (SELECT JobID, SUM(PriceExTax) Price 
           FROM JobStockItems 
           INNER JOIN Stock 
           ON JobStockItems.StockID = Stock.StockID
           AND Stock.Category1 = 'Hardware'
           GROUP BY JobID) jobstockitems_hardware
ON Job.ID = jobstockitems_hardware.JobID
LEFT JOIN (SELECT JobID, SUM(PriceExTax) Price 
           FROM JobStockItems 
           INNER JOIN Stock 
           ON JobStockItems.StockID = Stock.StockID
           AND Stock.Category1 = 'Consumables'
           GROUP BY JobID) jobstockitems_consumables
ON Job.ID = jobstockitems_consumables.JobID
GROUP BY DATEPART(m, Invoice.Date), 
         DATEPART(yy, Invoice.Date), 
         Reseller.Name
ORDER BY DATEPART(yy, Invoice.Date) ASC, 
         DATEPART(m, Invoice.Date) ASC, 
         Reseller.Name ASC

I’m assuming that Retailer has a column called Name that you want to return as well, feel free to change that to ID or whatever else you’d rather return.

Edit: Fixed query to remove duplicates