SQLDataMangement-notPrepared

<?php
    // Inputted filters' values
    $ItemNumber = $_POST["ItemSearch"];

    $MinWT = $_POST["minimum_wt"];
    $MaxWT = $_POST["maximum_wt"];

    $Shape = $_POST["shape"];

    $Color = $_POST["color"];

    $Enhancement = $_POST["enhancement"];

    $Matching = $_POST["matching"];

    /* SELECT ALL (with the alias of 'inv' [to not mix up the following request])
    FROM the 'stones' table WHERE 'wt' is greater than or equal to 2.5,
    then COUNT ALL and use the window function; OVER() to partition the COUNT AS a column
    called 'totalrows' */
    $SQL = "

        SELECT inv.*, COUNT(*) OVER() AS totalrows FROM stones inv WHERE wt >= 2.5

    ";

    // Filters
    if(isset($ItemNumber)) {

        $SQL .= "

            AND number LIKE '".$ItemNumber."%'

        ";

    }

    if(isset($MinWT, $MaxWT) && !empty($MinWT) && !empty($MaxWT)) {

        $SQL .= "

            AND wt BETWEEN '".$MinWT."' AND '".$MaxWT."'

        ";

    }

    if(isset($Shape)) {

        $ShapeFilter = implode("','", $Shape);

        $SQL .= "

            AND stoneshape IN('".$ShapeFilter."')

        ";
    }

    if(isset($Color)) {

        $ColorFilter = implode("','", $Color);

        $SQL .= "

            AND stonecolor IN('".$ColorFilter."')

        ";

    }

    if(isset($Enhancement)) {

        $EnhancementFilter = implode("','", $Enhancement);

        $SQL .= "

            AND enhcode IN('".$EnhancementFilter."')

        ";

    }

    if(isset($Matching)) {

        $MatchingFilter = implode("','", $Matching);

        $SQL .= "

            AND pair IN('".$MatchingFilter."')

        ";

    }

    // Pagination
    $PageNo = $_REQUEST['PageNo']; // Get page number

    $Limit = 25; // Maximum iterations per page
    $Offset = ($PageNo - 1) * $Limit; // Current page times the amount per page

    // $Offset and $Limit are declared in their respective variables
    $SQL .= "

        ORDER BY wt ASC LIMIT $Offset, $Limit;

    ";

?>