PHP explode and MySQL query to search in multiple columns - mysql

Question

I have a form where I want a user to enter one or more words. These words should then match mutiple columns in a MySQL database.
I have started to build some code but I'm stuck.
<?php
$term = $_SESSION['session_searchstring']; //Let's say that session is John Doe
$searchterm = explode(' ',$term);
$searchFieldName = "name";
$searchCondition = "$searchFieldName LIKE '%" . implode("%' OR $searchFieldName LIKE '%", $searchterm) . "%'";
$sql = "SELECT * FROM students WHERE $searchCondition;";
echo $sql; //Echo to test what mysql_query would look like
?>
The above code will output:
SELECT * FROM students WHERE name LIKE '%John%' OR name LIKE '%Doe%';
The problem is that I want to search in multiple columns ($searchFieldName). I have for example
customer_firstname
customer_lastname
And I want to match my searchstring against the content of both columns.. How would I continue?

Answer 1

Perhaps
$term = $_SESSION['session_searchstring']; //Let's say that session is John Doe
$searchterm = explode(' ',$term);
$searchColumns = array("customer_firstname","customer_lastname");
for($i = 0; $i < count($searchColumns); $i++)
{
$searchFieldName = $searchColumns[$i];
$searchCondition .= "($searchFieldName LIKE '%" . implode("%' OR $searchFieldName LIKE '%", $searchterm) . "%')";
if($i+1 < count($searchColumns)) $searchCondition .= " OR ";
}
$sql = "SELECT * FROM students WHERE $searchCondition;";
echo $sql; //Echo to test what mysql_query would look like
Produces
SELECT * FROM students WHERE (customer_firstname LIKE '%John%' OR customer_firstname LIKE '%Doe%') OR (customer_lastname LIKE '%John%' OR customer_lastname LIKE '%Doe%');

Answer 2

If your table is of MyIsam type or you can convert it to MyIsam, use MySQL Fulltext Search. if not, anyway, you can build a long query like
SELECT * FROM students WHERE name LIKE '%John%' OR name LIKE '%Doe%' OR lastname LIKE "%John%" OR lastname LIKE "%Doe%"
or union your columns into one another just for search (but this both are not prefered).
Also a good approach is to use fulltext search engines like Sphinx.

Answer 3

In my case I needed all search phrases/terms to match at least one column, no search phrase/term could be a no-match.
I ended up tweaking the example from Kermit in the following way:
public function getRawWhereFilterForColumns($filter, $search_columns)
{
$search_terms = explode(' ', $filter);
$search_condition = "";
for ($i = 0; $i < count($search_terms); $i++) {
$term = $search_terms[$i];
for ($j = 0; $j < count($search_columns); $j++) {
if ($j == 0) $search_condition .= "(";
$search_field_name = $search_columns[$j];
$search_condition .= "$search_field_name LIKE '%" . $term . "%'";
if ($j + 1 < count($search_columns)) $search_condition .= " OR ";
if ($j + 1 == count($search_columns)) $search_condition .= ")";
}
if ($i + 1 < count($search_terms)) $search_condition .= " AND ";
}
return $search_condition;
}
I only needed the contents of the Where-clause since I'm using Laravel and could put that into the rawWhere-method.
usage:
$search_condition = $this->getRawWhereFilterForColumns
("John Doe", array("column1", "column2"));
which produces
(column1 LIKE '%John%' OR column2 LIKE '%John%')
AND (column1 LIKE '%Doe%' OR column2 LIKE '%Doe%')
And finally you use this $search_condition in whatever way suits you, for example:
$sql = "SELECT * FROM students WHERE $search_condition;";
Or in my Laravel-case:
$modelInstances = Model::whereRaw
($search_condition)->paginate(self::ITEMS_PER_PAGE);
Perhaps this is an improved solution for either David or anybody else visiting this thread, like me, even if it's almost two years after the original post.