PHP MySQL counter/loop query - php

Question

I'm doing a MySQL query to search for items in a database. I've pulled variables out of the search form but I'm having some problems with my WHERE clause. As I don't want to search on fields that haven't been input in the form. The code I have at the minute is:
$query = " SELECT RequestID, clients.ClientName, clients.Username, RequestAssignee, requests.StatusID, requests.PriorityID, StatusName, PriorityName
FROM requests
INNER JOIN clients ON requests.ClientID = clients.ClientID
INNER JOIN statuses ON requests.StatusID = statuses.StatusID
INNER JOIN priorities ON requests.PriorityID = priorities.PriorityID
WHERE ";
if(!empty($RequestID))
{
$query2 .= "RequestID = '" . $RequestID . "' OR ";
}
if(!empty($ClientName))
{
$query2 .= "clients.ClientName = '" . $ClientName ."' OR ";
}
if(!empty($Username))
{
$query2 .= "clients.Username = '" . $Username . "' OR ";
}
if(!empty($RequestAssignee))
{
$query2 .= "RequestAssignee = '" . $RequestAssignee . "' OR ";
}
if(!empty($Status))
{
$query2 .= "statuses.StatusName = '" . $Status ."' OR ";
}
if(!empty($Priority))
{
$query2 .= "priorities.PriorityName = '" . $Priority ."'";
}
However you can see an issue whereby if someone only searches one field, the query adds an 'OR' to the end, resulting in an error:
SELECT RequestID, clients.ClientName, clients.Username, RequestAssignee, requests.StatusID, requests.PriorityID, StatusName, PriorityName FROM requests INNER JOIN clients ON requests.ClientID = clients.ClientID INNER JOIN statuses ON requests.StatusID = statuses.StatusID INNER JOIN priorities ON requests.PriorityID = priorities.PriorityID WHERE RequestID = '3' OR
Im guessing I'm going to have to put some sort of loop or counter in but unsure how to approach it. Any ideas?
Thanks, Matt.

Answer 1

$parts = array();
if(!empty($RequestID))
{
$parts[] = "RequestID = '" . $RequestID . "' ";
}
if(!empty($ClientName))
{
$parts[] = "clients.ClientName = '" . $ClientName ."' ";
}
if(!empty($Username))
{
$parts[] = "clients.Username = '" . $Username . "' ";
}
if(!empty($RequestAssignee))
{
$parts[] = "RequestAssignee = '" . $RequestAssignee . "' ";
}
if(!empty($Status))
{
$parts[] = "statuses.StatusName = '" . $Status ."' ";
}
if(!empty($Priority))
{
$parts[] = "priorities.PriorityName = '" . $Priority ."' ";
}
$query2 .= implode(' OR ', $parts);

Answer 2

Ok so the way i would approach this is to build the variables that will form your where clause separatley:
This could be done in an array:
FIELD1=>'Value1';
FIELD2=>'Value2';
I would then loop over this array, for the first element, i=1 i would build in a WHERE, for i+n -> i+(n-1) i would pre-pend an OR, for the last array value i wouldn't do anything.
I can then use the string i build in this loop - to stick into my query string.
Have a go at something like this and give us a shout if you need more help. Doing it this way is slightly more maintainable also.