java - 尝试将从图形 API 调用的字符串放入数据库 sq-lite，但数据库中的值为 null

Question

我和我的团队已经这样做很多天了，但仍然不明白我想要做的是使用 Graph API Facebook 调用用户 ID(已经完成并通过使用日志检查它是否工作)并将该值放入 sq-lite 数据库中，但当我检查该值时它是 NULL。抱歉英语能力不好。这是一些代码

String userId, userName; //Global values
loginButton.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
        @Override
        public void onSuccess(LoginResult loginResult) {
            data = new Data(getApplicationContext());
            SQLiteDatabase db = data.getWritableDatabase();
            GraphRequest request = GraphRequest.newMeRequest(
                    AccessToken.getCurrentAccessToken(),
                    new GraphRequest.GraphJSONObjectCallback() {
                        @Override
                        public void onCompleted(JSONObject object,
                                                GraphResponse response) {

                            userId = object.optString("id");
                            Log.d("id", userId); 
                        }
                    });
            request.executeAsync();
            db.execSQL("INSERT INTO Information (userId) VALUES ('" + userId +"');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('First exercise', 'Exercise', '10');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Stronger', 'Exercise', '50');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Body builder', 'Exercise', '100');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('First check-in', 'Check-in', '1');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Go around', 'Check-in', '10');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Become tourist', 'Check-in', '50');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Traveller', 'Check-in','100');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Wait! Is this the same place?', 'Check-in', '1');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('First time here', 'Todo', '1');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('So busy', 'Todo', '10');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Business man', 'Todo', '50');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('What todo first', 'Todo', '100');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('First times Saving', 'Saving', '1');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Money kids style', 'Saving', '10');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Way to rich', 'Saving', '200');");
            db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Rich boy', 'Saving', '2000');");
            db.close();
            data.close();
            loginState();
        }

Answer 1

当数据库 userId 值尚未初始化时，您尝试写入该值。 GraphRequest.newMeRequest 在其他线程中执行，需要等待 onCompleted 被调用，然后写入 db。

  GraphRequest request = GraphRequest.newMeRequest(
                AccessToken.getCurrentAccessToken(),
                new GraphRequest.GraphJSONObjectCallback() {
                    @Override
                    public void onCompleted(JSONObject object,
                                            GraphResponse response) {

                        userId = object.optString("id");
                        Log.d("id", userId); 
        db.execSQL("INSERT INTO Information (userId) VALUES ('" + userId +"');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('First exercise', 'Exercise', '10');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Stronger', 'Exercise', '50');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Body builder', 'Exercise', '100');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('First check-in', 'Check-in', '1');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Go around', 'Check-in', '10');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Become tourist', 'Check-in', '50');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Traveller', 'Check-in','100');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Wait! Is this the same place?', 'Check-in', '1');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('First time here', 'Todo', '1');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('So busy', 'Todo', '10');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Business man', 'Todo', '50');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('What todo first', 'Todo', '100');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('First times Saving', 'Saving', '1');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Money kids style', 'Saving', '10');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Way to rich', 'Saving', '200');");
        db.execSQL("INSERT INTO Achievement (AName, AType, AScore) VALUES ('Rich boy', 'Saving', '2000');");
        db.close();
        data.close();
        loginState();
                    }
                });
        request.executeAsync();