Retrieve Data From DB using PHP

Question

I created a database (table) in SQL similar to this.

   x   y   z
1  x1  y1  z1
2  x2  y2  z2

This is a table that I created; now I want to do some math on it using PHP. How can I retrieve the data and perform math on it? How to get data from the DB table and save them in PHP variables?

function ans($x1, $y2, $z2)
{
#a = x1 - y2;
#z2 = $z2 -$a;
}

Which DBMS are you using? How did you create the table and load the data? — Jonathan Leffler
– Jonathan Leffler, Commented Jul 20, 2012 at 5:46
i am using www.000webhost.com , first i created db in sql than i use phpmyadmin . — Faheem Ali
– Faheem Ali, Commented Jul 20, 2012 at 7:37

Conrad Lotz · Accepted Answer · 2012-07-20 05:42:38Z

1

The code will look as follow:

<?php

 $con = mysql_connect("localhost","username","password");
 if (!$con)
   {
   die('Could not connect: ' . mysql_error());
   }

mysql_select_db("database", $con);

$xAnswer = 0;
$yAnswer = 0;
$zAnswer = 0;

$result = mysql_query("SELECT x,y,z FROM MathTable");

while($row = mysql_fetch_array($result))
   {
     $xAnswer = Add($row["x"],$row["y"]);
     $yAnswer = Multiply($row["z"],$row["y"]);
     $zAnswer = Subtract($row["z"],$row["x"]);
   }

mysql_close($con);


    function Add($x,$y)
    {
       return $x + $y;
    }

    function Subtract($x,$y)
    {
       return $x-$y;
    }

    function Multiply($x,$y)
    {
       return $x*$y;
    }

    function Divide($x,$y)
    {
       return $x/$y;
        }
 ?>

Alternatively one can handle the math in the sql as well as follow and then just pull the answers into a variable:

SELECT (x+y) AS Add,(x-y) AS Subtract,(z/x) AS Divide FROM MathTable

The the loop through the recordsset will be as follow

while($row = mysql_fetch_array($result))
       {
         $xAnswer = $row["Add"];
         $yAnswer = $row["Subtract"];
         $zAnswer = $row["Divide "];
       }

Remember that the variables will have a different answer everytime the loop increments because of the amount of records in the table so you might want a running total or alternatively you can keep running total inside using the above Add example variables:

$xAnswer = $xAnswer  + $row["Add"];

answered Jul 20, 2012 at 5:42

Conrad Lotz

8,9533 gold badges25 silver badges28 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Conrad Lotz Over a year ago

Please ensure that all the casting of variables are also taken into account. To do math strings must be coverted to int or float, etc

Faheem Ali Over a year ago

thanks for your answer it helped me alot . can you tell me how can i access specific elements in a table from lot of rows . by using . SELECT X_colm FROM MY_TABLE WHERE ID= 2; SELECT Y_colm FROM MY_TABLE WHERE ID=6; i want some thing like this ... You USed while loop it will continue in series .can i access specific row with this .

Faheem Ali Over a year ago

thanks alot i figered it out GUYS $result = mysql_query("SELECT x,y,z FROM MathTable WHERE id =4"); $result2 = mysql_query("SELECT x,y,z FROM MathTable WHERE id=56"); $row = mysql_fetch_array($result); $row2 = mysql_fetch_array($result2); $xAnswer = Add($row["x"],$row2["y"]); $yAnswer = Multiply($row2["z"],$row["y"]); $zAnswer = Subtract($row2["z"],$yAnswer); should i use it

e03050 · Accepted Answer · 2012-07-20 10:48:38Z

0

mysql_connect is going to be deprecate. http://php.net/manual/en/function.mysql-connect.php

use mysqli instead http://www.php.net/manual/en/book.mysqli.php

answered Jul 20, 2012 at 10:48

e03050

1,59216 silver badges13 bronze badges

Collectives™ on Stack Overflow

Retrieve Data From DB using PHP

2 Answers 2

3 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related