Mysqli Error for Count (Distinct) Query

[Eric Hilding]

Probably something very simple, but I cannot figure it out. Any help is greatly appreciated !!!

*** I am trying to just get a simple COUNT of all "Unique" Last Names in the 'lastname' column.

(ERROR)

Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given...(in this line of code: $count = mysqli_fetch_array($result);)

(QUERY)

$sql = "SELECT COUNT (DISTINCT lastname) FROM contacts";

$result = mysqli_query($con,$sql);

$count = mysqli_fetch_array($result);

$uniques = $count[0];

echo $uniques . "Total Uniques";

Thank you very much.

-Eric