Pass a variable to query on home page

jamjam

I am new to PHP development.

I am building a dynamic website that will pull data from Mysql database.

I know the easiest way to retieve data from a database in php is to pass variables with a query string.

How can I do this on default page that does not contain a query string.

For example if my homepage was www.example.com and I wanted to pull data from the database to populate the homepage. How would I do this?

I could add a query string to the end of the page and link to it that way but this will be no good if someone typed just the homepage and not the full string.

Am sure there is easy solution to do this but as I am new to this,
I am stomped.

Will appreciate any assistance.

dabaR

Something like this in your PHP:

if(empty($_GET['param'])) {
  $db_parameter = 'default';
} else {
$db_parameter = $_GET['param'];
}
db_query("SELECT FROM table WHERE thing = " . db_quote($db_parameter));

You could rewrite the if...else with a ternary, optionally (don't use it if you are unfamiliar with the ternary operator):

$db_parameter = empty($_GET['param']) ? 'default' : $_GET['param'];

db_quote() and db_query() do not really exist, they are meant to be replaced with actual DB functions. Those for mysql can be found here: http://php.net/manual/en/book.mysql.php , or you can use PDO, which provides database-agnostic set of functions: http://ca.php.net/manual/en/book.pdo.php

Hope that helps!

Dan Bernardic
http://dan.bernardic.ca

laserlight

The use of the query string is to provide some data that the script that process accordingly, e.g., a page number such that it can compute the desired rows to retrieve from the database.

But here you do not want to provide such data. The script corresponding to this page will simply do its job, retrieving whatever is desired from the database.

jamjam

Thanks for the reply.

I understand that corresponding script on the page should retrieve data from the database.
But how does it do this without specifying the varibles in the query string.

I was looking for some way of auto redirecting to a query string.

So for example if someone typed www.example.com they will automatically go to www.example.com?date=01-06

I will not be able to add html redirct code to my homepage because the query string will change daily.

I think a solution that redirects the page to a query string that is dynamically retreived from the database is what I am looking for.

laserlight

You can do that by sending an appropriate location [man]header[/man], but why not just display the same information as would be displayed when the query string is set to that?

jamjam

Can the location header information be stored on the database and retrieved dynamically? Also will this slow down the time takes to load the page, for example will this solution involve "please wait you are been redirected"?

On the second point, I thought the only way to retrieve data from the database is to specify the relavant variables on url string.

jamjam

dabaR.

I somehow did not see your reply.

Your solution looks interesting and maybe what I am looking for.

Will look into it. Thanks

laserlight

jamjam wrote:
On the second point, I thought the only way to retrieve data from the database is to specify the relavant variables on url string.

No, it is not. The query string has nothing to do with the database, other than what your script does with it. You are probably confusing "query string" with "database query".

jamjam

Let me explain my current setup.

I am working on localhost with PHP and Mysql.

When I type http://localhost/home/?date=01-06 into my browser,
I can retrieve results from my database that match the dated specified in the query string.

I want to setup a default page where I do not need to add the query string but still returns a result for the current day.

I could use html redirects but this will involve updating that address everyday, not ideal.
I want some dynamic way of doing this.

dabaR

Ya, my posts are put in a moderation queue to be approved since I just joined.

Show the line of PHP that goes to the database currently, please.

jamjam

Not sure about which line you mean so i decided to provide the whole script.
This PHP will eventually will inserted into a html template.

I created this with Dreamweaver CS4 by the way.

<?php require_once('Connections/date.php'); ?>
<?php require_once('../Connections/search_db.php'); ?>
<?php
if (!function_exists("GetSQLValueString")) {
function GetSQLValueString($theValue, $theType, $theDefinedValue = "", $theNotDefinedValue = "")
{
if (PHP_VERSION < 6) {
$theValue = get_magic_quotes_gpc() ? stripslashes($theValue) : $theValue;
}

$theValue = function_exists("mysql_real_escape_string") ? mysql_real_escape_string($theValue) : mysql_escape_string($theValue);

switch ($theType) {
case "text":
$theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
break;

case "long":
case "int":
$theValue = ($theValue != "") ? intval($theValue) : "NULL";
break;
case "double":
$theValue = ($theValue != "") ? doubleval($theValue) : "NULL";
break;
case "date":
$theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
break;
case "defined":
$theValue = ($theValue != "") ? $theDefinedValue : $theNotDefinedValue;
break;
}
return $theValue;
}
}

if (!function_exists("GetSQLValueString")) {
function GetSQLValueString($theValue, $theType, $theDefinedValue = "", $theNotDefinedValue = "")
{
if (PHP_VERSION < 6) {
$theValue = get_magic_quotes_gpc() ? stripslashes($theValue) : $theValue;
}

$theValue = function_exists("mysql_real_escape_string") ? mysql_real_escape_string($theValue) : mysql_escape_string($theValue);

mysql_select_db($database_date, $date);
$query_rs84 = "SELECT Date, String FROM search";
$rs84 = mysql_query($query_rs84, $listings) or die(mysql_error());
$row_rs84 = mysql_fetch_assoc($rs84);
$totalRows_rs84 = mysql_num_rows($rs84);

$coldate_rs83 = "=1";
if (isset($GET['date'])) {
$coldate_rs83 = $GET['date'];
}
mysql_select_db($database_search_db, $search_db);
$query_rs83 = sprintf("SELECT * FROM search WHERE Date = GetSQLValueString($coldate_rs83, "text"));
$rs83 = mysql_query($query_rs83, $search_db) or die(mysql_error());
$row_rs83 = mysql_fetch_assoc($rs83);
$totalRows_rs83 = mysql_num_rows($rs83);
?>

dabaR

jamjam;10954070 wrote:

$coldate_rs83 = "=1";
if (isset($_GET['date'])) {
  $coldate_rs83 = $_GET['date'];
}
mysql_select_db($database_search_db, $search_db);
$query_rs83 = sprintf("SELECT * FROM search WHERE Date = GetSQLValueString($coldate_rs83, "text"));

That's the relevant piece. Even if you just change:

$coldate_rs83 = "=1";

$coldate_rs83 = date('Y-m-d');

That will probably do what you want. That will make the default date be today, whatever today is at the time the script runs.

dabaR

$query_rs83 = sprintf("SELECT * FROM search WHERE Date = GetSQLValueString($coldate_rs83, "text"));

That has an uneven number of double quotes, so it likely does not compile. You will probably need

$query_rs83 = sprintf("SELECT * FROM search WHERE Date = " .  GetSQLValueString($coldate_rs83, "text"));

jamjam

WOW. Thats cool.

I edited the code when I pasted into the browser so properly deleted something that was already there. For you to spot something so small you must know what you are doing.

I will try out your solution and report back

Thanks again

dabaR

jamjam;10954073 wrote:
WOW. Thats cool.
I edited the code when I pasted into the browser so properly deleted something that was already there. For you to spot something so small you must know what you are doing.

I'm a human compiler :-)

jamjam

YES YES YES!!!!

It works.

I can't believe it. Such a simple solution yet so perfect.

The only thing I changed was the date format to dd-mm with no year specified.

Thanks man

I owe you bigtime .

dabaR

:-)

Do you plan to run the site only for one year? You better incorporate the year if you intend to run it for longer than a year.

jamjam

The site will contain TV Listings data after one year the data will be old and get overwritten with new data.
I could add the year but this will increase the data entry task so have decided to ommit it.