php - 从 mysql 编写正确的 JSON 结构

Question

我正在尝试从 mysql 检索数据，然后将其显示在 android listview 上。我试过一些教程，但我不知道如何编写可以将数据从 mysql 发送到 android 的正确代码。

这是我一直在做的用于测试的 JSON 结构。

{
"users": [
    {
            "id": "001",
            "name": "John",
            "email": "john@gmail.com",
            "gender" : "male"
    },
    {
            "id": "002",
            "name": "Mary",
            "email": "mary@gmail.com",
            "gender" : "female"
    } 
]}

如果所有这些数据都在 mysql 数据库中，具有表“USERS”并且由“ID”、“NAME”、“EMAIL”、“GENDER”组成怎么办？
如何编写 JSON用 mysql？？

这是 Android 中显示数据的代码。

// JSON Node names
private static final String TAG_USERS = "users";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_GENDER = "gender";
JSONArray users = null;
.
.
.
try {
        // Getting Array of Users
        contacts = json.getJSONArray(TAG_USERS);

        // looping through All Users
        for(int i = 0; i < users.length(); i++){
            JSONObject c = users.getJSONObject(i);

            // Storing each json item in variable
            String id = c.getString(TAG_ID);
            String name = c.getString(TAG_NAME);
            String email = c.getString(TAG_EMAIL);
            String gender = c.getString(TAG_GENDER);

Answer 1

你必须使用 json_encode() 功能。

// MySQL query, maybe you already have something similar
$query = 'SELECT * FROM users LIMIT 5';
$res = mysql_query($query);

// Push all records from the database into a single array
$users = array();
$users['users'] = array(); // Your "users" key for JSON
while ($user = mysql_fetch_assoc($res)) {
    $users['users'][] = $user;
}

// Encode and output that array as JSON, then end the script
echo json_encode($users);
exit();