How to update value of a column as difference between two variables in sql?

Question

Here, update chooses bal(for balance) column of register table whose is to be changed to difference of bal and the value in variable $tax for only the row saisfying the condition. It's not working in following code.How to do it?

$query3 = mysql_query('update table register set  bal=bal-'.$tax.' where name='.$user.')' , $connection);

[Answer is here](http://stackoverflow.com/questions/5383108/update-a-column-by-subtracting-a-value). BTW, you should definitively forget about `mysql` extension and use PDO. — Dan Chaltiel, Oct 20 '15 at 21:27

score 1 · Accepted Answer · edited Oct 21 '15 at 03:12

1

You are using in an incorrect way.

Try this:

$query3 = mysql_query("update table register set  bal=(bal-$tax) where name='$user'" , $connection);

edited Oct 21 '15 at 03:12

o-90

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answered Oct 20 '15 at 21:29

Manish Shukla

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score 0 · Answer 2 · answered Oct 20 '15 at 21:31

0

It seems, there is extra ')' after user, that hasn't '('

answered Oct 20 '15 at 21:31

Val K

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How to update value of a column as difference between two variables in sql?

2 Answers2