PhpStorm无法识别类中的PDO方法

Question

Not sure exactly how to ask this question. But I'm using PhpStorm as my IDE.

I created a class that will handle my database retrieval and manipulation. In it I have this connect method:

private function connect() {

        $dsn = 'mysql:host=' . $this->host . ';dbname=' . $this->db;
        $options = [
            PDO::ATTR_PERSISTENT => true,
            PDO::ATTR_ERRMODE    => PDO::ERRMODE_EXCEPTION
        ];
        try {
            $this->conn = new PDO($dsn, $this->user, $this->pass, $options);
        } catch(PDOException $e) {
            $this->error = $e->getMessage();
        }

    }

The method works fine, but when I go to use $this->conn in other methods PhpStorm does not recognize $this->conn as a PDO object.

Using this method:

private function insert() {
        $insert = $this->conn->prepare($sql);
        $insert->execute();
    }

PhpStorm says that it can't find the method prepare or execute.

If I pass $this->conn into the method and use a PHPDoc block on the parameter it works fine:

/**
 * @param $conn pdo
 */
private function insert($conn) {
    $insert = $conn->prepare($sql);
    $insert->execute();
}

I'm curious as to why it won't let me use $this->conn? While it's not that much more code to pass $this->conn to the method, just seems a bit redundant.

Any ideas on what I need to do differently?

Answer 1

Use @var before the definition of the property:

/**
 * @var PDO
 */
private $conn;

That way you tell PhpStorm, that the following variable (property) is of type PDO. Note that private here depends on your code, this is here just an example.

Take a look at this to learn more about PHP Documentation Comments in PhpStorm.