CODEWITHSUNDEEP
phpmysqlshopping-cart
ravi404
ravi404

Reputation: 7309

Changing Default Currency in shopping cart

If this question seems like a possible duplicate, I'm sorry. please link me to the original.

I am developing a shopping cart with php and mysql.

In the admin panel, multiple currency types can be set, and new currency types can be added. It will have a default currency and a coversion rate. My problem is when changing the default currency type.

This is what my tables look like

**Currency**
------------------------------------------------------------------------------
ID    CurrencyType        ConversionRate           IsDefault
------------------------------------------------------------------------------
1       type1                 -                      y
2       type2                 2.0                    n
3       type3                 3.0                    n
------------------------------------------------------------------------------

**Product**
------------------------------------------------------------------------------
ID     Rate        
------------------------------------------------------------------------------
1      100
2      200      
------------------------------------------------------------------------------

Here for the price for product 1 will be 

(100) for currency type1
(100 * 2.0) for currency type2
(100 * 3.0) for currency type3

In the admin panel, the conversion rates will added with respect to the default currency type.

Here while changing the default type, I can update the conversion rates in the currency table. But I am having to update the rate in the product table. Changing the rates for all products in the product table, made me feel that I am wrong.

Is there any other better way to do.? please advice.

Upvotes: 2

Views: 1322

Answers (2)

ravi404
ravi404

Reputation: 7309

I found a solution with which i need not update the product table.. I am gonna have a HIDDEN currency type which will be the default for the calculations.. The rate in the product table will be always be *1 to this currency type

Can make the necessary calculations in the admin panel so that the admin can still enter the rate of the new product in his default currency type..

Upvotes: 0

Alex Kalicki
Alex Kalicki

Reputation: 1533

Now that I understand your question I am relatively sure that you'll have to update both tables. If you simply wanted to display the table to the user in a different conversion rate but keep the underlying cost the same, then you could always store the value in CurrencyType type1 but convert it to type2 or type3 in php when displaying it to the user. But if you want the actual values in the Product table to update when you update the default CurrencyType, and not just the way that they are displayed to the user, then you'll have to update both tables.

Luckily, SQL makes this very easy since all you're effectively doing is multiplying the current Rate value by the ConversionRate you're changing it to. So if you have a php variable storing the ConversionRate of the new CurrencyType before you make it default:

UPDATE Product
SET Rate = Rate * oldConversionRate

should update all rows in the Product table with the new Product rates. Let me know if that was confusingly worded or you'd like more clarification.

Upvotes: 1

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