how to form select query by range

bonny

hello i have a search engine for my site. i have two selection fields. i would like to give an example:

input_a: 3
input_b: 5

so the queries should look like:

if ( ($input_a == true) && ($input_b == false) ){
        $filter_orders[] = " `col` LIKE '%$input_a%' ";
    } 
    if ( ($input_a == false) && ($input_b == true) ){
        $filter_orders[] = " `col` LIKE '%$input_b%' ";
    } 
    if ( ($input_a == true) && ($input_b == true) ){
        $filter_orders[] = " `col`= `col`>='%$input_a%' AND `col` = `col`<='%$input_b%' ";

now the problem is, that i dont know, if the last query is incorrect or not. the logic behind that will be that in case of my example the range between 3 and 5 should be found.

so 1,2 [3,4,5] 6,7,8…

if there is someone who could help me out i really would appreciate.

thanks a lot.