I'm pretty new in PHP and MYSQL. I've got this form that I use to enter data into a database I created. I add up values from two fields in separate columns and insert the value into a third column (TOTAL_IN). Then I subtract another value (VALUE3) that's in another field from the value in a field in the third column (TOTAL_IN) and put that value in a different column. All these are in the same table. It works just fine, but the problem is that when I open up my database I see that the data has been inserted 20 or 100 times! How can I stop the data from being inserted so many times?
Please note that the submit button was clicked only once.
Here is what I use:
$sql="INSERT INTO $tbl_name (id, date, value1, value2, total_in, value3, value4)
SELECT '','$date','$value1','$value2',('$value1'+'$value2') AS SUM,
'$value3',(('$value1'+'$value2')-$value3) AS SUM
FROM $tbl_name";
$result=mysql_query($sql);
any help?
Thanks in advance!
EDIT::: Here is what my code looks like now after your suggestions:
//From Ruddy's post
$total_in=$value1+$value2;
$value4=($value1+$value2)-$value3;
//From Amit's post
$sql="INSERT INTO $tbl_name(id, date, value1, value2, total_in, value3, value4) VALUES ('', '.$date.', '.$value1.', '.$value2.', '.$total_in.', '.$value3.', '.$value4.')";
$result=mysqli_query($sql);
it works but it still enters the data many times.