php - json_encode不返回任何内容

我正在尝试将MYSQL表数据转换为JSON。我正在尝试使用json_encode()。但这是行不通的。它不返回任何东西。我已经检查了控制台，甚至没有抛出任何错误。我想念什么？

<?php
    //open connection to mysql db
    $connection = mysqli_connect("localhost","root","","maps") or die("Error " . mysqli_error($connection));

    //fetch table rows from mysql db
    $sql = "select * from locations";
    $result = mysqli_query($connection, $sql) or die("Error in Selecting " . mysqli_error($connection));

    //create an array
    $emparray[] = array();
    while($row =mysqli_fetch_assoc($result))
    {
        $emparray[] = $row;
    }
    echo json_encode($emparray);

    //close the db connection
    mysqli_close($connection);
?>

最佳答案

尝试这个

while ( $row = $result->fetch_assoc() ){
    $emparray[] = json_encode($row);
}
echo json_encode( $emparray );

或者

while($row =mysqli_fetch_assoc($result))
{
   $emparray[] = json_encode($row);
}
echo json_encode($emparray);

或者

$emparray = $result->fetch_all( MYSQLI_ASSOC );
echo json_encode( $emparray );

代替

 while($row =mysqli_fetch_assoc($result))
    {
        $emparray[] = $row;
    }
    echo json_encode($emparray);