使用php PDO从数据库获取所有用户的列表

Question

I am trying to get a list of players from database with specific range of latitude and longitude. The query works fine and give me results. However these results may include more than one player. Current code as shown below gives me JSON Encoded only one player. How can I get all players JSON ENCODED.

function GetPlayersInRange() 
    {
        try {
            $conn = $this->GetDBConnection();

            $long1 = trim($_REQUEST['long1']);
            $long2 = trim($_REQUEST['long2']);
            $lat1  = trim($_REQUEST['lat1']);
            $lat2  = trim($_REQUEST['lat2']);


            $statement = $conn->prepare('SELECT * FROM players WHERE longitude > :long1 AND longitude < :long2 AND latitude > :lat1 AND latitude < :lat2');
            $statement->bindParam(':long1', $long1, PDO::PARAM_STR);
            $statement->bindParam(':long2', $long2, PDO::PARAM_STR);
            $statement->bindParam(':lat1' , $lat1, PDO::PARAM_STR);
            $statement->bindParam(':lat2' , $lat2, PDO::PARAM_STR);
            $statement->execute();

            if(!($row = $statement->fetch(PDO::FETCH_ASSOC))) 
            {
                return "No Players";
            }

            $conn = null;
        } catch(PDOException $e) {
            throw $e;
        }

        return $row;
    }

Answer 1

Change $statement->fetch to $statement->fetchAll . Fetch will only "Fetch the next row from a result set" whereas fetchAll will "Return an array containing all of the result set rows".

Answer 2

You shouldn't be comparing string to int/double in your query. When using PDO::PARAM_STR, it'll wrap your data in single quotes. Try to use PDO::PARAM_INT here.