mysqli PHP search and filter by two databases/tables in MySQL

Question

I am trying to search and filter by two different databases.

DATABASE1.table1  |   DATABASE2.table1
id | col2         |   id | ref_col2 | ref_col3
1  | 2            |   1  | thing    | thing
2  | 500          |   2  | other    | other

I know you can use the following if its on the same database:

$search = explode(" ", mysqli_real_escape_string($connection, $_POST["search_string"]));
$search_string = " AND (";
for($i=0;$i<count($search);$i++){
    $search_string .= "(t2.ref_col2 LIKE '%".$search[$i]."%' OR t2.ref_col3 LIKE '%".$search[$i]."%') AND ";}
$search_string = substr($search_string,0,strlen($search_string)-4);
$search_string .= ")";  


$query = mysqli_query($connection, "SELECT t1.*, t2.* AS row_count FROM table1 AS t1 LEFT JOIN  table2 AS t2 ON t1.id = t2.id WHERE t1.id>0".$search_string)or die();

My question is: What if they are on two different databases? is there a specific way to select one database.table results by searching another database.table's list the above?

Answer 1

if they are on the same server then

database1.table1 AS t1 LEFT JOIN  database2.table2 AS t2 

should be fine