HTML/PHP code to add numbers to a whole sum

Question

Lets just say I am keeping track of money. So I have my balance in a mysql database. My balance would be $100

I want to create a html script so when I enter say 50 and hit submit it will change the database value to 150.

I know the basics of how to connect to a mysql and insert and get data from a database, thats no problem I done that many times but instead of hitting submit and having the value change to just 50 how can I code it so it just adds on to the value so it will be 150?

You can first fetch the value present in the database and simply add the new value with the same — Riken Shah, Apr 23 '16 at 19:49

score 1 · Answer 1 · answered Apr 23 '16 at 19:52

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To change balance for specific user your mysql query must be like:

UPDATE users SET balance = balance + 50 WHERE id = 1

answered Apr 23 '16 at 19:52

f0rtis

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Thank you! Can't believe I never knew that loi – NeedtoKnow Basis Apr 23 '16 at 20:48

score 1 · Accepted Answer · edited May 23 '17 at 12:31

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Assuming $value contains the number you want to add to the amount.

$sql = "UPDATE table_name SET current_balance = current_balance + $value`;

Running the query will add $value to whatever you had as current_balance. You can read up on prepared statements, SQL injection etc to make the query I've written more secure.

edited May 23 '17 at 12:31

Community

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answered Apr 23 '16 at 19:57

Iro

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Thank you! Can't believe I never knew that loi – NeedtoKnow Basis Apr 23 '16 at 20:48

HTML/PHP code to add numbers to a whole sum

2 Answers2