if() else function doesn't work in a loop

Question

I have this table

cityreportcomment :
-----------------
reportID (fK)
cityID (fK)
comment

EDIT: if city has no comment, there is no row in the table: a row (for a city) exists only if that city has a comment.

for every report, I print 13 cities (that are in another table). I would like to check if city has a comment, then echo comment, if not, echo 'different'; but my code doesn't work.

for ($i = 0; $i < 13; ++$i) {

    $stmt = $conn->prepare("SELECT * FROM cityreportcomment WHERE reportID=? AND cityID=?");
    if (!$stmt) {
        die(printf("Error: %s.\n", mysqli_stmt_error($stmt)));
    } else if (!$stmt->bind_param('ii', $reportID, $selectcityID_array_unique[$i])) {
        die(printf("Error: %s.\n", mysqli_stmt_error($stmt)));
    } else if (!$stmt->execute()) {
        die(printf("Error execute from ereportcomment table: %s.\n", mysqli_stmt_error($stmt)));
    } else {
        $result = $stmt->get_result();
        while ($row = $result->fetch_assoc()) {
            if (isset($row['cityID']) && $row['cityID'] == $selectcityID_array_unique[$i]) {
                $selectcomment2[] = 'same' . $row['cityID'] . (isset($row['comment']) ? $row['comment'] : "");
            } elseif (!isset($row['cityID']) || $row['cityID'] != $selectcityID_array_unique[$i]) {
                $selectcomment2[] = 'different';
            }
        }
    }
    /* end else */

    $stmt->close();

    echo $i . ' ' . $selectcomment2[$i] . '<br>';

} //end for

PROBLEM:

if $i=1 has comment, $i=2 no comment, $i=3 has comment, $i=4 no comment, my echo results is

1 comment1

2 comment3

3

4

5

.....

It should be


1 comment1

2 different

3 comment3

4 different

5 different

.....

SOLUTION:

Thanks to everybody for your help: after reading every answer and every comment, this is what I did (very important is to unset $comment2 at the beginning of the loop):

for ($i = 0; $i < 13; ++$i) {
    unset( $selectcomment2 ); //veeeery important
    $stmt = $conn->prepare("SELECT * FROM cityreportcomment WHERE reportID=? AND cityID=?");
    if (!$stmt) {
        die(printf("Error: %s.\n", mysqli_stmt_error($stmt)));
    } else if (!$stmt->bind_param('ii', $reportID, $selectcityID_array_unique[$i])) {
        die(printf("Error: %s.\n", mysqli_stmt_error($stmt)));
    } else if (!$stmt->execute()) {
        die(printf("Error execute from ereportcomment table: %s.\n", mysqli_stmt_error($stmt)));
    } else {
        $result = $stmt->get_result();
        while ($row = $result->fetch_assoc()) {
                     $selectcomment2 = $row['comment'];
            }         
  }
    /* end else */

    $stmt->close();

  if ( !isset($selectcomment2 ) ){
          $selectcomment2 = 'different';
  }

    echo $i . ' ' . $selectcomment2[$i] . '<br>';

} //end for

Thanks again (please don't edit this line, I really appreciate all the help I received)

Answer 1

Use this instead:

if (child.name == "MapContainer") {
    continue;
}

Your if/else doesn't work because you are checking if while ($row = $result->fetch_assoc()) { if (!empty($row['cityID']) && $row['cityID'] == $selectcityID_array_unique[$i]) { $selectcomment2[] = 'same' . $row['cityID'] . (!empty($row['comment']) ? $row['comment'] : ""); } elseif (empty($row['cityID']) || $row['cityID'] != $selectcityID_array_unique[$i]) { $selectcomment2[] = 'different'; } else { continue; # do nothing } } "is set", in other words, if it exists or not... However, because you are using it on a mysql loop where you are returning those fields, they will always be set (exist). I suspect that what you want to check is, if $row['cityID'] is empty or not, which in that case you could use $row['cityID'] instead.

!empty()

Answer 2

You have this SQL:

public class MyResource extends AbstractResource {
        private Manager manager;

        @Inject
        public MyResource(@Named("authorization") Authorization auth,
                          @Named("helper") Helper helper) {
            super(auth, helper);
            this.manager = new Manager();
        }
...

You are binding "SELECT * FROM cityreportcomment WHERE reportID=? AND cityID=?" to the $selectcityID_array_unique[$i] placeholder, so every record returned will have a cityID equal to cityID.

Then you are checking this:

$selectcityID_array_unique[$i]

Naturally, it will always be true. If no records are returned from the query, you will not see if (isset($row['cityID']) && $row['cityID'] == $selectcityID_array_unique[$i]) { , because the while loop will execute zero times.

You can fix it like this:

different

Answer 3

If the comment is empty, it won't be !isset.

This code should do what you want:

I would like to check if city has a comment, then echo comment, if not, echo 'different'

string input;
int num;
cout << "Enter a series of number, then type Q to process: ";
while(true)
{
 cin >> input;
 if(input == "q" || input == "Q")
    break;
 num = strtol(input.c_str());
 .....
}