Question

i have a variable and an user_name i want to search on a string(function_description) of the user_name for it

whats wrong with this :

$function_keywords = mysql_real_escape_string($_POST['function_keywords']);
if($function_keywords=="" || empty($function_keywords)){
    redirect("show.php?functions=PHP");
}
//trim whitespace from the stored variable
$trimmed = trim($function_keywords);
//separate key-phrases into keywords
$trimmed_keywords = explode(" ",$trimmed);
// Build SQL Query for each keyword entered
foreach ($trimmed_keywords as $trimm){
// MySQL "MATCH" is used for full-text searching.
//this code is ebv weird , should check out soon!
$query = "SELECT * 
          FROM functions
          WHERE isEnabled=1 AND isPrivate=0
          AND function_description LIKE '{$trimm}' 
          AND user_name='{$user_name}'   
          ";
 // Execute the query to  get number of rows that contain search kewords
 $results=mysql_query ($query,$connection);

Answer 1

That’s highly inefficient. If someone puts in 5 keywords, you’d be running the search 5 times and getting 5 sets of results. Try something more along these lines:

$words = $_POST['function_keywords'];
if ($words == '') {
    ... abort ...
}

$parts = trim(explode(' ', $words));
$clauses = array();
foreach($parts as $part) {
    $clauses[] = "function_description LIKE '%" . mysql_real_escape_string($part) . "%'";
}

$clause = implode(' OR ' , $clauses);

$sql = "SELECT .... WHERE (isEnabled=1) AND (isPrivate=1) AND (user_name='$user_name') AND ($clause)";
$result = mysql_query($sql) or die(mysql_error());

This’ll build up a long series of or statements for each keyword specified, and run the whole thing as a single query.