在php中显示表中的数据

Question

$sql=" SELECT * from `request_location` where requestid = '".$requestid."' ";
    $result = mysqli_query($con, $sql);
    if(mysqli_num_rows($result)>0)
        {
            echo "(";
            while($row = mysqli_fetch_assoc($result))
                {
                    echo  $row["location_tag"]; 
                    echo ",";
                }
            echo ")";   
        }

I have this above code that displays data in a format where the result is placed within round brackets and each term is separated by a comma

The result that i am getting is like this

(a,b,c,)

Although it seems to be fine but i want that the comma should not appear after c as it is the last term like this

(a,b,c)

Can anyone please tell how to remove comma after the last element

Answer 1

Solution 1:

You can do it using implode() function and array().

Logic behind it:

1) Take a blank array.

2) Fetch the results the same way as existing.

3) Append results to the array.

4) After the loop ends implode() the array with a comma.

5) Add a prepending and post pending ( and ) to the result.

sql=" SELECT * from `request_location` where requestid = '".$requestid."' ";
$result = mysqli_query($con, $sql);
$arr = array();
if(mysqli_num_rows($result)>0) {
  while($row = mysqli_fetch_assoc($result)) {
    $arr[] = ["location_tag"]; 
  }
}
echo ! empty($arr) ? '(' . implode(',', $arr) . ')' : '';

Solution 2:

Use MYSQL's GROUP_CONCAT() (if you want to fetch only one field from database table).

sql=" SELECT GROUP_CONCAT(location_tag) from `request_location` where requestid = '".$requestid."' ";
    $result = mysqli_query($con, $sql);
    $ids = '';
    if(mysqli_num_rows($result)>0) {
      while($row = mysqli_fetch_assoc($result)) {
        $ids = ["location_tag"]; 
      }
    }

echo ! empty($ids) ? '(' . $ids . ')' : '';