sql multiplication don't show properly total - sql

There is strange multiplication in the script.
SUM(CAST(PurchLine.[Amount Including VAT] AS decimal(10,2)))
OVER(PARTITION BY PurchLine.[Document No_])AS "TotalAmount"
Finding the Total Amount from above.
TotalAmount * TotalAmount * Discount AS PaymentAmount
Finding the discount and final Payment Amount from the above.
For example I have 24.80 * (24.80*0.015) = 24.42
Instead of that I receive 24.30.
Also for the discount 24.80*0.015 = 49.60 This is not correct again. The correct result would be 0.372
But the strange part this is not working only when TotalAmount is lower than 3 digits. When the Total amount is below 100, always the discount is not correct.
I'm not sure what do I have to make so it would work all the time.

The problem was that the this table with column Discount was imported into the sql server from excel file. For some reason the column Discount was not Decimal.
All the column contain numbers like 0.0015, 0.010 and so on...
When I change the column datatype to decimal(10.4) for Discount everything start working fine.
But here is still the question, why this work for number bigger than 100 and for less than 100 don't work?

Related

Correct way to calculate prices including tax in foreign currencies

I'm trying to upgrade an application so that I can sell to multiple countries. I store all of my prices in the database in GBP excluding tax up to 4dp and I need to calculate the prices in the country's currency including tax.
Do I multiply the price by the exchange rate against the price excluding tax (option 1) or do I calculate the amount including tax and then multiple by the exchange rate (option 2)? I have also added an option 3 after looking at how OpenCart calculates it which is similar to option 2 but only ever rounds when displaying it. Here are the formula's for all 3 options:
Option 1:
Round((Price * Exchange Rate) / 100 * (100 + Tax Rate))
Option 2:
Round(Round(Price / 100 * (100 + Tax Rate)) * Exchange Rate)
Option 3:
Round((Price / 100 * (100 + Tax Rate)) * Exchange Rate)
For example say I have a product with a price of 89.99. If I wanted to display that in a currency with an exchange rate of 1.5 and a tax rate of 20%. Would I say:
Option 1:
Round((89.99 * 1.5) / 100 * (100 + 20)) = 161.98
Option 2:
Round(Round(89.99 / 100 * (100 + 20)) * 1.5) = 161.99
Option 3:
Round((89.99 / 100 * (100 + 20)) * 1.5) = 161.98
I've found that OpenCart always multiplies the unrounded figures by the exchange rate at the end. For example their formula for calculating the line total is:
Round((Price / 100 * (100 + Tax Rate)) * Quantity * Exchange Rate)
So if I was to order 3 of my product's it would give:
Round((89.99 / 100 * (100 + 20)) * 3 * 1.5) = 485.95
The problem I find doing it OpenCart's way is the user will see an item price (including tax) of 161.98 and a line total of 485.95. However if I say 161.98 * 3 I get 485.94, so it doesn't sum up correctly.
It's important I get this right as you can see I'll end up with penny issues. I'd appreciate it if someone could let me know which way is correct or suggest an alternative if none are right. Thanks
Since all variables are rounded except Exchange Rate, which I would expect to usually look something like this 1.3462, we can write a test like this:
// I'm guessing you need it in PHP
$price = 89.99;
$quantity = 1;
$tax = 20;
$tax = $tax/100.0 + 1;
// $tax = 1.2
$exchangeRate = 1.5;
$totalPrice = $price*$quantity*$tax; // Test #1
$totalPriceRounded = round($price*$quantity*$tax,2); // Test #2
echo $totalPrice.'<br/>'.$totalPriceRounded;
Which would have this output:
107.988 // Test #1 <--- This is amount that needs to be paid to you and Great Britain
107.99 // Test #2 <--- rounded
Now, it's obvious there is a difference in amount, so which to choose? Since you are charging an item from Great Britain, you expect to get paid the full amount you are asking for, in GBP, so lets rely on that factor. In the end, if I understood correctly, the tax the customer has to pay is tax to Great Britain.
Lets check the final prices in foreign currency:
$totalPrice = round($totalPrice * $exchangeRate,2);
$totalPriceRounded = round($totalPriceRounded * $exchangeRate,2);
echo $totalPrice.'<br/>'.$totalPriceRounded;
Which would have this output:
// Amount in foreign currency
161.98 // Test #1
161.99 // Test #2
With all that said, lets check which one of these would return you a value closest to 107.988 GBP when calculated back to GBP from foreign currency.
// To calculate the totalPrice back to price*tax*quantity in GBP
$totalPrice /= $exchangeRate;
$totalPriceRounded /= $exchangeRate;
echo $totalPrice.'<br/>'.$totalPriceRounded;
Output of which is:
// totalPrice in GBP currency
107.98666666667 // Test #1
107.99333333333 // Test #2
And when we divide by tax:
$totalPrice /= $tax;
$totalPriceRounded /= $tax;
echo $totalPrice.'<br/>'.$totalPriceRounded;
Output is:
// the amount you get in GBP currency
89.988888888889 // End result of Test #1
89.994444444444 // End result of Test #2
So as you can see, in this case, by using the bare amount of round($price*$quantity*$tax*$exchangeRate, 2) you are getting less, but by using round(round($price*$quantity*$tax,2)*$exchangeRate, 2) you get a little more which again, rounded both give the same value. In some other scenario the difference will likely be different from what we got here and might be the other way around.
CONCLUSION
If you have a fixed number of products each with fixed prices then you will be either loosing money (an insignificant amount) or earning more than you should (also an insignificant amount) over time. The outcome depends on the popularity and price of each product (i.e. will the round function round up or down), and on the way of calculation you chose. You could, depending on product popularity, manually adjust the prices of each product to minimize the loss/gain over time.
If you have products with random prices like lets say you are renting web servers and the price is $0.01/second. Then the expectation value for your loss/gain is close to zero. And the more purchases are made the closer to zero it gets. So you are not loosing anything here regardless of the approach. One time you win some one time you loose some.
In my opinion I would standardize it to round everything:
$price = 4.47;
$quantity = 1.2 // lets say liters
// Even round the price before applying tax
$totalPrice = round($price * $quantity, 2);
because if you are forced to show all the different stages of calculation then you will have to round every step.
But the most precise would be to use this as the least information is lost:
// Round once at end
$totalPrice = round($price*$quantity*$tax*$exchangeRate, 2);
In the end it all depends on how you set up your product prices or how your pricing works to be able to choose which method to go with. I'd say it doesn't really matter, I think every company simply chooses what suits them best.
Legally, some countries/cities/etc. have laws on how to calculate this, you should be looking at Great Britain laws to check on the valid procedure for your problem.
I can't tell you what the correct option is or even if there is one correct option. But from experience I can say, if there are multiple options to do one thing, make it configurable in your software. In this case you can easily use the strategy pattern and make the strategy for calculating prices configurable. Customers can choose how they want it calculated.
The correct solution depends on your business. When you sell items in different countries, you most likely have branches in those countries - and you need a net price in those country's currency. This results in the net price per item "translated" to the foreign currency, and this net price is then multiplied with the amount and multiplied with the tax factor/percentage).
The EU MOSS (which is charged when you offer services in other countries, or e.g. software as download) is somehow different. You can sell products with GBP pricing, but have to consider your consumer's local tax factor. See e.g. https://ec.europa.eu/taxation_customs/sites/taxation/files/resources/documents/taxation/vat/how_vat_works/telecom/one-stop-shop-guidelines_en.pdf
For MOSS, I didn't check in detail, but I expect that you then have a different formula, using your local GBP net price per item, multiply with amount, multiply with consumer's tax percentage. This tax amount, still in GBP, should then be multiplied with currency exchange rate, I'd expect.

SQL query issue with zero discount

I am using the below query to get total amount after a discount.
My issue is when the discount is equal to zero, the total amount becomes zero.
How can I resolve this issue?
SELECT
CAST(SUM(Quantity * UnitPrice * (Discount / 100)) AS varchar(50))
FROM
Stock_Purchase_Details
simple case construct
unitPrice *
case when discount > 0 then (discount / 100)
else 1 end
That's for the code you posted. Normally, a discounted price is
unitPrice * ((100 - discount) / 100)
If you want final amount after discount, you should use
CAST(SUM(Quantity * UnitPrice * (1-(Discount/100)) AS VARCHAR(50))
This will give you the amount after discount. Your current formula gives you the amount discounted, not the amount after discount
Why not check to see if Discount/0 is 0 before doing that, and if it is zero, then don't include it? This can be done via case statements:
CASE
WHEN (Discount/100) = 0 then (logic)
ELSE (other logic)
END
Just one solution, as I am sure there are others.
Just by looking at your query, Discount means percentage discounted, not percent discount. In other words, per your SQL query, if Discount is 60%, it doesn't mean 60% off, but it's 40% off.
I'm assuming that's not what you want, so the correct query should be:
SELECT Cast(SUM(Quantity * UnitPrice * ((100-Discount)/100)) as varchar(50))
from Stock_Purchase_Details

Missing Expression Error when I try to convert the currency type

I want to display the output of total price from my table as 'USD 20.00' or 'EURO 40' for US and Euro respectively.
I tired the following code and got the missing expression error.
How to convert it to the specified format?
The data type of the column 'price' is number.
My code goes here..
select convert(varchar(50),convert(money, coalesce(sum(nvl(CASE
WHEN (typ=27 and l.tyt ='USD') THEN 'USD' + PRICE
WHEN (typ=27 and l.tyt='EURO') THEN 'EURO'+ PRICE
END,0)),0)),1) as Total from transactions;
Thanks in advance!
There are several things wrong with the expression. 1) adding string value ('USD'/'EURO') to numeric value (PRICE), 2) NVL() on different data type, 3) SUM() on a string data. Anyone of these could be the cause of the error.
If the table stores differently denominated prices, you cannot sum them into on row - which one do you want to be in the result (EURO or USD). If you want to have both in two rows, the the following should work (note that in your original statement, the alias l is undefined so this is not likely to work):
SELECT 'USD', Sum(price) as Total
FROM transactions
WHERE typ=27 and tyt ='USD'
UNION ALL
SELECT 'EURO', Sum(price) as Total
FROM transactions
WHERE typ=27 and tyt ='EURO'
or simply
SELECT tyt, Sum(price) as Total
FROM transactions
WHERE typ=27
GROUP BY tyt

How to accurately figure percentage of a finite total

I’m in the process of creating a report that will tell end users what percentage of a gridview (the total number of records is a finite number) has been completed in a given month. I have a gridview with records that I’ve imported and users have to go into each record and update a couple of fields. I’m attempting to create a report tell me what percentage of the grand total of records was completed in a given month. All I need is the percentage. The grand total is (for this example) is 2000.
I’m not sure if the actual gridview information/code is needed here but if it does, let me know and I’ll add it.
The problem is that I have been able to calculate the percentage total but when its displayed the percentage total is repeated for every single line in the table. I’m scratching my head on how to make this result appear only once.
Right now here’s what I have for my SQL code (I use nvarchar because we import from many non windows systems and get all sorts of extra characters and added spaces to our information):
Declare #DateCount nvarchar(max);
Declare #DivNumber decimal(5,1);
SET #DivNumber = (.01 * 2541);
SET #DateCount = (SELECT (Count(date_record_entered) FROM dbo.tablename WHERE date_record_entered IS NOT NULL and date_record_entered >= 20131201 AND date_record_entered <= 20131231);
SELECT CAST(ROUND(#DivNumber / #DateCount, 1) AS decimal(5,1) FROM dbo.tablename
Let’s say for this example the total number of records in the date_record_entered for the month of December is 500.
I’ve tried the smaller pieces of code separately with no success. This is the most recent thing I’ve tried.
I know I'm missing something simple here but I'm not sure what.
::edit::
What I'm looking for as the expected result of my query is to have a percentage represented of records modified in a given month. If 500 records were done that would be 25%. I just want to have the 25 (and trainling decimal(s) when it applies) showing once and not 25 showing for every row in this table.
The following query should provide what you are looking for:
Declare #DivNumber decimal(5,1);
SET #DivNumber = (.01 * 2541);
SELECT
CAST(ROUND(#DivNumber / Count(date_record_entered), 1) AS decimal(5,1))
FROM dbo.tablename
WHERE date_record_entered IS NOT NULL
and date_record_entered >= 20131201
AND date_record_entered <= 20131231
Why do you select the constant value cast(round(#divNumber / #DateCount, 1) as decimal(5,1)from the table? That's the cause of your problem.
I'm not too familiar with sql server, but you might try to just select without a from clause.
select emp.Natinality_Id,mstn.Title as Nationality,count(emp.Employee_Id) as Employee_Count,
count(emp.Employee_Id)* 100.0 /nullif(sum(count(*)) over(),0) as Nationality_Percentage
FROM Employee as emp
left join Mst_Natinality as mstn on mstn.Natinality_Id = emp.Natinality_Id
where
emp.Is_Deleted='false'
group by emp.Natinality_Id,mstn.Title

How to calculate new value for field in Access

I've got a few problems with a database I have created.
I want to calculate a Total Price (Sandwich Quantity multiplied by Sandwich Price). I had it working before, but I had to delete Sandwich Price from the OrderDetailsT table of which it was originally in. I'm now having issues with this calculation, as I cannot make a calculation in the OrderDetailsT table (Sandwich Price isn't there).
How can I apply the Discount to the Total Price if the Total Price is more than $50 for instance? After the Discount has been applied to the Total Price field, I would also like to store it in the NewPriceAfterDiscount field.
Here is an image detailing my situation:
You have multiple questions in one:
But, first of all. As the image shows, why do you have a left join between OrderDetails an Sandwich? In a order calculation you don't need not ordered sandwiches.
To total price calculation:
Add a new column to the query grid (assuming discount is a percentaje stored has a number between 0 and 1):
[SandwichT].[SandwichPrice] * [OrderDetailT].[SandwichQuantity] * [OrderDetailT].[Discount]
To store total price: you can use the above formula, but using a update query.
If you plan to show the prices in a form or in a report:
you can do de calculations on the fly (and don't store the total
price)
or you should update the total price un one query and then build another
query as datasource of the form/report.
another posibility (my recomendation) is to store the total in the input form