I want to build a query form my database depending my checkboxes list.

My checkboxes:

<input type="checkbox" id="searchName" checked> Name
<input type="checkbox" id="searchAddress"> Address
<input type="checkbox" id="searchCompany"> Company
<input type="checkbox" id="searchComments"> Comments

My PHP:

$subQuery='';
if($_POST['searchName']=='true')     { $subQuery .= " AND KDX_Name LIKE :KDX_SearchTerm"; }
if($_POST['searchAddress']=='true')  { $subQuery .= " OR KDX_PostalAddress LIKE :KDX_SearchTerm"; }
if($_POST['searchCompany']=='true')  { $subQuery .= " OR KDX_Company LIKE :KDX_SearchTerm"; }
if($_POST['searchComments']=='true') { $subQuery .= " OR KDX_Comments LIKE :KDX_SearchTerm"; }

My problem:

If the first checkbox is not checked, my query is not working cause it works with OR whereas it must start with AND.

Could you please help ?

Thanks.

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You have many mistakes in your code in HTML and in PHP ... I'll not mention everything here, but this is how I would do this.

<input type="checkbox" name="searchName" checked="checked" />Name
<input type="checkbox" name="searchAddress" />Address
<input type="checkbox" name="searchCompany" />Company
<input type="checkbox" name="searchComments" />Comments

<?php
$fields = array(
    'searchName'    => 'KDX_Name',
    'searchAddress' => 'KDX_PostalAddress',
    'searchCompany' => 'KDX_Company',
    'searchComments'=> 'KDX_Comments',
);

$cond = array();
foreach ($fields as $form_field => $db_field) {
    if (isset($_POST[$form_field])) {
        $cond[] = "$db_field LIKE '%'" . mysql_escape($_POST[$form_field]) . "%'";
    }
}

$subQuery = implode(' OR ', $cond);
?>

More important are these things:

• correct HTML form (not id, but name),
• easy to extend PHP (use array for field names),
• don't check for $_POST[foo]=='true' which is absolutely wrong,
• add conditions in array and at the end use implode to easily concatenate everything together,
• escape user input variables to avoid SQL injection attacks.