I have this PHP code that runs a query. The result from "count" is 0, hence, it should enter "else". However, even if it does, what I get is the error "Undefined offset: 0" and "Trying to get property 'num_rows' of non-object" on $sql14, because the array is empty and doesn't have the index provided. This part of the code shouldn't run, however it is running.

What can I do to prevent this? I've added the else part to return that there's no values in the database but, since there's an error on $sql14, it doesn't get printed out.

$sql12 = "SELECT COUNT(idItem) as count 
            FROM items, type 
            WHERE type_description = 'jacket' 
            AND items.type = type.idType;";

$fetched12 = $conn -> query($sql12);

if($fetched12 -> num_rows > 0){

    while($row12 = $fetched12 -> fetch_assoc()){

        $jacket_count = $row12['count'];
        $random = rand(1, $jacket_count-1);

        $sql13 = "SELECT * FROM items, type WHERE type_description = 'jacket' AND items.type = type.idType;";

        $fetched13 = $conn -> query($sql13);

        if($fetched13 -> num_rows > 0){

            while($row13 = $fetched13 -> fetch_assoc()){

                array_push($all_jackets, $row13['idItem']);
            }
        }
    }

    $sql14 = "SELECT * FROM items WHERE idItem = ".$all_jackets[$random].";";

    $fetched14 = $conn -> query($sql14);

    if($fetched14 -> num_rows > 0){

        while($row14 = $fetched14 -> fetch_assoc()){

            $id_jacket = $row14['idItem'];
            $jacket = $row14['item_description'];
        }
    }
} else {
    $jacket = "no jackets on database";
}

CodePudding user response：

$fetched12 -> num_rows is a number of fetched rows

And in your case number of fetched rows is 1. Ands this row is

You should use value of count but not number of rows