Consulting about inventory database design

Question

0.00/5 (No votes)

See more:

I have a question about inventory project database design

Instead of creating a [ProductBalance] column in products table, I left the balance undefined and created another table [Log]
Log_ID || Product_ID || OperationType_ID   || Input || Output
1            29           1 (Purchases)         5        0
2            24           4 (Sales)             0        2
3            24           5 (SaleReturn)        1        0

* OperationType_ID is related to another table[OperationTypes]

Now when user select some product the query will SUM(Input) - SUM(Output) for this product to get the current balance.

What I have tried:

This worked well till now, but i want to know is this design is bad?
For example when i wanted to get total sales and saleReturn for products i tried this:
SELECT SUM(A.Output) AS Sales, SUM(B.Input) AS SaleReturn
FROM
(SELECT * from Log WHERE Log.OperationType_ID = 2) A
FULL JOIN
(SELECT * FROM Log WHERE Log.OperationType_ID = 5) B ON A.Stock_ID = B.Stock_ID

Posted 17-Nov-18 7:07am

XRushdy

Updated 17-Nov-18 9:24am

v2

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

MadMyche · Accepted Answer · 2018-11-17T09:25:00

First thing is that the definition you give in the "content" section does not match the condition you give in the query

OperationTypeID = 4 (Sales)

SUM(A.Output) AS Sales = (SELECT * from Log WHERE Log.OperationType_ID = 2)

Second thing was that your query seems quite wordy. You could replace that with something a lot simpler

SQL

SELECT Sales = Sum(Output), SalesReturn = Sum(Input)
FROM @log
WHERE OperationTypeID IN (4, 5)

As for the log table design, I would have additional columns for items such as LogDateTime & TransactionID. I also have an aversion to column names that are either keywords or reserved words; notice that Output is blue in the query, so I would probably rename to something like InventoryRemoved and then change the input column to be similarly named like InventoryAdded