如何通过API从Wikidata获取美国各州的名单？

Question

我试图用维基数据API找到美国的州，但没有结果。

例如：http://wdq.wmflabs.org/api?q=claim[150:30]

• P150 - contains administrative territorial entity
• Q30 - United States of America

我做错了什么？

Answer 1

您需要P31值为Q35657的所有维基数据项目：claim[31:35657]

• P31 - instance of
• Q35657 - state of the United States

Answer 2

使用SPARQL，您可以这样做

$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

$city = "Amersfoort";

/* create a prepared statement */
if ($stmt = $mysqli->prepare("SELECT District FROM City WHERE Name=?")) {

    /* bind parameters for markers */
    $stmt->bind_param("s", $city);

    /* execute query */
    $stmt->execute();

    /* bind result variables */
    $stmt->bind_result($district);

    /* fetch value */
    $stmt->fetch();

    printf("%s is in district %s\n", $city, $district);

    /* close statement */
    $stmt->close();
}

/* close connection */
$mysqli->close();
?>

try it here