This is a web application that is meant to conduct transaction after being connected to Database. But, it seems i still haven't positioned the BEGIN and COMMIT perfectly. Please drop your input if any!


if(isset($_POST['amount']))
{
if(isset($_POST['ADD']) && $number !=""
{
mysql_query("BEGIN";
$query="UPDATE accounts SET balance='balance+amount' WHERE number='12345'";
mysql_query($query);
}
else
{
$query="UPDATE accounts SET balance='balance-amount' WHERE number='12345'";
mysql_query($query);
}

mysql_query("COMMIT";

what's the error you get obviously we don't have the same table you have. why not throw an exception there and see what you get.

pc guru: what's the error you get obviously we don't have the same table you have. why not throw an exception there and see what you get.

Thanks for the concern.
Acutally, no error is being displayed, but i expect the the balance to have increased or decreased in the database, and which is not happening. I guess the issue is more like a semantic error not syntactic.

mysql_query() commits queries automatically so no need to commit changes, you also want to remove the mysql_query("BEGIN" );

this line

$query="UPDATE accounts SET balance='balance+amount' WHERE number='12345'"; 

does not make sense, even if balance and amount were constants, it still wont work that way
i believe you wanted to do something like this

$query="UPDATE accounts SET balance='$balance+$amount' WHERE number='12345'"; 

which will still not give you the desired result
why not add things up before append the query like this

$finalBalance=$balance+$amount;
$query="UPDATE accounts SET balance='$finalBalance' WHERE number='12345'"; 

remember, if the balance column in your database is of type INT, then you want remove the quote, same with the quote around 12345


I also want to believe you have selected your database before trying that query.

to be on the safe side always prefer to evaluate the expression and save the result to the db its cleaner that way

D-sense:
This is a web application that is meant to conduct transaction after being connected to Database. But, it seems i still haven't positioned the BEGIN and COMMIT perfectly. Please drop your input if any!


if(isset($_POST['amount']))
{
if(isset($_POST['ADD']) && $number !=""
{
mysql_query("BEGIN";
$query="UPDATE accounts SET balance='balance+amount' WHERE number='12345'";
mysql_query($query);
}
else
{
$query="UPDATE accounts SET balance='balance-amount' WHERE number='12345'";
mysql_query($query);
}

mysql_query("COMMIT";

Look at what I have put in bold. That's not correct variable declaration.
What you should have there is

$query="UPDATE accounts SET balance = balance + '$amount' WHERE number='12345'";

AND

$query="UPDATE accounts SET balance = balance - '$amount' WHERE number='12345'";

Assuming the variable holding the amount is $amount.
i.e $amount = $_POST['amount'];



Then again, although the whole MySQL BEGIN thing is not necessary and should be removed its still good to point to you that you have placed it in a wrong place. If it was necessary to use the BEGIN command, it should have been placed outside the IF block checking if the operation is an addition. You have placed yours inside the IF block that will only run if the operation is an addition. So if the operation is not addition, the BEGIN query wont run. Discard the BEGIN and keep the principle in mind for future tasks.

webdezzi: mysql_query() commits queries automatically so no need to commit changes, you also want to remove the mysql_query("BEGIN" );

this line



does not make sense, even if balance and amount were constants, it still wont work that way
i believe you wanted to do something like this



which will still not give you the desired result
why not add things up before append the query like this





remember, if the balance column in your database is of type INT, then you want remove the quote, same with the quote around 12345


I also want to believe you have selected your database before trying that query.

your head is there jare!