[SOLVED] Problem using SUM

[woodsonoversoul]

Can anyone please explain why this doesn't return the sum of the values stored in "price"...

 

// Compute total spent
  $sql = "SELECT SUM(price) AS total FROM purchase";
  if ($result = $mysqli->query($sql)) {
    if ($mysqli->num_rows()) {
      $row = $result->fetch_assoc();
      echo $row['total'];
    }
  } else {
    echo $mysqli->error;

[woodsonoversoul]

When I use that code I get:

 

Fatal error: Call to undefined method mysqli::num_rows()

 

All help is greatly appreciated. Thanks in advance

[teng84]

try
// Compute total spent
  $sql = "SELECT SUM(price) AS total FROM purchase";
  if ($result = $mysqli->query($sql)) {
    if ($result->num_rows) {
      $row = $result->fetch_assoc();
      echo $row['total'];
    }
  } else {
    echo $mysqli->error;

[woodsonoversoul]

Thanks so much! That totally fixed it. Could you you go one step further and explain why that code works and mine didn't? I mean I see the parenthesis were removed but could you go into a little more detail? Thanks again

[teng84]

u use $mysqli but i use $result

if ($result->num_rows)

 

because its already passed by that and remove ()

ok hope that helps mark this as solved

[woodsonoversoul]

It does. Thanks again