I am looking for some experienced advice when it comes to functions and query statements.

I am writing code that I am constantly having to query a db, does it make sense to create a function that I call every time and return result or is it better to just make the calls in the main body of the code. It just seems that I am forever just typing the same six or so lines over and over.

I have attached a sample of what I currently have and a proposed function. I know the idea of functions it reuse what you have already done but I am not sure if this also applies to db queries as it may cause confusion??

I guess part of my question also lies in the fact that I really do not understand what is being returned in the result, is is a pointer to the db or an array of values. In which case, is it better to open the db, query and close the db all in a very neat package.

Looking for some worldly advice?

<?php
// start session
session_start();
// set up some global variables
@include 'salutations.php';
@include 'globalcfg.php';
@include 'db_connect.php';
$sql='SELECT quote, image, quoted FROM tbl_list_quotes ORDER BY RAND() LIMIT 1';
$result = mysql_query($sql, $link);
if (!$result) {
echo 'DB Error, could not query the database MySQL Error: '.mysql_error();
exit;
}
$row = mysql_fetch_assoc($result);
$quote=$row['quote'].'<br /><br />-- '.$row['quoted'].' --';
echo $_GET["project_id"];
if(isset($_GET["project_id"])) $_SESSION["project_id"]=$_GET["project_id"];
if(isset($_GET["tab"])) $_SESSION["tab"]=$_GET["tab"];
if(empty($_SESSION["tab"])) $_SESSION["tab"]=2;
echo $_SESSION["tab"].'PID'.$_SESSION["project_id"];
?>

or should I just call a function like

function query($sql){
@include 'globalcfg.php';
@include 'db_connect.php';
$result=mysql_query($sql, $link);
if (!$result) {
echo 'DB Error, could not query the database MySQL Error: '.mysql_error();
exit;
}
return $result;
// dispose of result set
mysql_free_result($result);
// close connection to database server
mysql_close($link);
}

If you find you are doing things over and over again writing a function is probably a good idea.

Looking at your proposed function, however, I see some potential problems: If you plan on calling your query function multiple times in a single execution you'll want to move your includes outside of the function (or if you must, use include_once instead of include). The same thing applies to connecting to and closing your database connection; if you're calling query more than once it is wasteful to connect and close your connection every time it is called.

Its always better to have Database related function (ie for CURD operation) in a separate file and as functions. Respective functions shall be called where ever necessary.

The benefits are
1. Its very easy to debug , when ever something goes wrong.

2. The code will be neat

Thanks for your advice.

A question regarding the includes, what I found was that the function did not seem to be aware of the db connection so I moved it inside of the function, is this something that needs to be passed to the function or should it be available globally?

You need to declare your variable as 'global' inside your function..

For example, if $db is your database connection object..then inside your function..

function functionname
{
global $db;

// your function definition here
}

and need to include the file inside the function, also its not a good practice to do this, since PHP will include the file every time you call the function.

Instead if you include it outside, it will be included once..