php change value to 0 from any number

Question

guys

I don't know why but php convert my value into 0 each time.

So, i have video table. Inside i have a row called like and dislike. Lets say i have 10 dislike.

Every time i check previously value like that:

$sql = "SELECT * FROM video WHERE video_id = '$id'";
    $result = mysqli_query($conn, $sql);
    while($row = $result->fetch_assoc()){
        $like=$row['vid_like'];
        $dislike=$row['vid_dislike'];

and i echo dislike i got 10 in return

Just after that i do that for increase dislike:

$dislike1= $dislike +1;
echo "dis = {$dislike1}";
$sqla = "UPDATE video SET vid_dislike='$dislike1' AND vid_like='$like' WHERE video_id = '$id' ";
mysqli_query($conn, $sqla);

my echo result is 11. But when i check table after that query, my dislike value is set to 0...

Just in case you are not aware, these queries are vulnerable to SQL injection. If you want to know more, [this link](https://stackoverflow.com/questions/60174/how-can-i-prevent-sql-injection-in-php) may be useful. — Travis Britz, Mar 10 '19 at 23:17
Your query should be `UPDATE video SET vid_dislike='$dislike1', vid_like='$like' WHERE video_id = '$id' ";` note `,` in place of `AND` — Nick, Mar 10 '19 at 23:57

score 0 · Answer 1 · answered Mar 10 '19 at 23:10

Your update query is not well formatted.

It must look like this :

UPDATE t1 SET col1 = col1 + 1, col2 = col1;

See documentation.

Here you wrote "AND" instead of a comma, which is by the way useless in this case since the second part is vid_like='$like' where $like value didn't change.

php change value to 0 from any number

1 Answers1