使用关联数组进行PHP到JSON编码

echo json_encode（$data）只打印（$data）

打印数组，不打印任何内容。如何将数据数组转换为json格式

require "constant.php";
require "database.php";
$sql = "select e.*, b.booth_address, ba.bank_full_name from $app_booth_enrolment e
left join $app_booth_info b on e.booth_id=b.booth_id
left join $app_bank_info ba on e.bank_id=ba.bank_id";
$result = $conn->query($sql);
if($result->num_rows > 0){
    $data = array();
    while($row = $result->fetch_assoc()){
        array_push($data,$row);
    }
    echo $data = json_encode($data);  
    var_dump(json_encode($data));
}else{
    $data['status'] = "No terminal found";
    echo $data = json_encode($data);
}

---

我找到了解决办法

Havelock建议打印

json\u last\u error\u msg（）

，我发现格式错误的UTF-8字符，可能编码不正确

我使用的是

MySQLi

，所以我必须在数据库连接后插入这一行以进行字符格式设置：

MySQLi\u set\u字符集（$conn，“utf8”）

谢谢Havelock。
尝试使用yii2 encode（）函数：您能告诉我们打印（$data）

中有什么吗？

var_转储（json_encode（$data））的确切功能是什么returnvar_dump（json_encode（$data））；返回bool（false），如果是这种情况，那么您应该打电话查看出了什么问题
Array
(
    [0] => Array
        (
            [id] => 1
            [enrolment_id] => 101-1-0001
            [terminal_type_id] => ATM
            [booth_name] => CITY-Bashundhara
            [enrolment_date] => 2015-01-01
            [live_date] => 2015-02-02
            [bank_id] => 101
            [booth_id] => 101-0001
            [terminal_serial] => 5300153835
            [terminal_host] => TCBL-TWO
            [terminal_app] => 
            [note] => 
            [status] => 1
            [insert_by] => 1
            [insert_date] => 
            [booth_address] => Head Office, Jiban Bima Tower, 10, Dilkusha Commercial Area, Dhaka-1000 
            [bank_full_name] => The City Bank Limited
        )

    [1] => Array
        (
            [id] => 2
            [enrolment_id] => 101-1-0002
            [terminal_type_id] => ATM
            [booth_name] => CITY-VIP_Road
            [enrolment_date] => 2015-01-01
            [live_date] => 2015-02-02
            [bank_id] => 101
            [booth_id] => 101-0002
            [terminal_serial] => 5300153831
            [terminal_host] => TCBL-TWO
            [terminal_app] => 
            [note] => 
            [status] => 1
            [insert_by] => 1
            [insert_date] => 
            [booth_address] => Head Office, Jiban Bima Tower, 10, Dilkusha Commercial Area, Dhaka-1000 
            [bank_full_name] => The City Bank Limited
        )

    [2] => Array
        (
            [id] => 3
            [enrolment_id] => 101-2-0003
            [terminal_type_id] => CDM
            [booth_name] => CITY-DSE
            [enrolment_date] => 2015-01-01
            [live_date] => 2015-02-02
            [bank_id] => 101
            [booth_id] => 101-0003
            [terminal_serial] => 5300153832
            [terminal_host] => TCBL-TWO
            [terminal_app] => 
            [note] => 
            [status] => 1
            [insert_by] => 1
            [insert_date] => 
            [booth_address] => Head Office, Jiban Bima Tower, 10, Dilkusha Commercial Area, Dhaka-1000 
            [bank_full_name] => The City Bank Limited
        ) 
)