Question

我在sqlite中有一个数据库我试图在textview或listiew中显示登录表的名称列。

在 databeaseHAndler 类中，我使用HashMap从表中选择所有用户，但我不知道如何在textview中显示该查询的结果（如果可以使用ashmap ）或Listview。

理想情况下，它们应该只是表中的一条记录，这就是为什么我希望它显示在textview中，基本上显示登录到我的应用程序的用户。有谁知道怎么做？

我的 Databasehandler 类：

 public class DatabaseHandler extends SQLiteOpenHelper {


    // All Static variables
    // Database Version
    private static final int DATABASE_VERSION = 1;

    // Database Name
    private static final String DATABASE_NAME = "u168512214_barzd";

    // Login table name
    private static final String TABLE_LOGIN = "login";

    // Login Table Columns names
    private static final String KEY_ID = "id";
    private static final String KEY_NAME = "name";
    private static final String KEY_EMAIL = "email";
    private static final String KEY_UID = "uid";
    private static final String KEY_CREATED_AT = "created_at";

    public DatabaseHandler(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    // Creating Tables
    @Override
    public void onCreate(SQLiteDatabase db) {
        String CREATE_LOGIN_TABLE = "CREATE TABLE " + TABLE_LOGIN + "("
                + KEY_ID + " INTEGER PRIMARY KEY,"
                + KEY_NAME + " TEXT,"
                + KEY_EMAIL + " TEXT UNIQUE,"
                + KEY_UID + " TEXT,"
                + KEY_CREATED_AT + " TEXT" + ")";
        db.execSQL(CREATE_LOGIN_TABLE);
    }

    // Upgrading database
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // Drop older table if existed
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_LOGIN);

        // Create tables again
        onCreate(db);
    }

    /**
     * Storing user details in database
     * */
    public void addUser(String name, String email, String uid, String created_at) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KEY_NAME, name); // Name
        values.put(KEY_EMAIL, email); // Email
        values.put(KEY_UID, uid); // Email
        values.put(KEY_CREATED_AT, created_at); // Created At

        // Inserting Row
        db.insert(TABLE_LOGIN, null, values);
        db.close(); // Closing database connection
    }





 /**
     * Getting user data from database
     * */
        public HashMap<String, String> getUserDetails(){
            HashMap<String,String> user = new HashMap<String,String>();
            String selectQuery = "SELECT  * FROM " + TABLE_LOGIN;

        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(selectQuery, null);
        // Move to first row
        cursor.moveToFirst();
        if(cursor.getCount() > 0){
            user.put("name", cursor.getString(1));
            user.put("email", cursor.getString(2));
            user.put("uid", cursor.getString(3));
            user.put("created_at", cursor.getString(4));
        }
        cursor.close();
        db.close();
        // return user
        return user;
    }


    /**
     * Getting user login status
     * return true if rows are there in table
     * */
    public int getRowCount() {
        String countQuery = "SELECT  * FROM " + TABLE_LOGIN;
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(countQuery, null);
        int rowCount = cursor.getCount();
        db.close();
        cursor.close();

        // return row count
        return rowCount;
    }

HomeFragment类我要在哪里显示名称：

public class HomeFragment extends ListFragment {
TextView username;
UserFunctions userFunctions;
Button btnViewBars;
Button btnNewBar;
private DatabaseHandler userDetails;

AlertDialogManager alert = new AlertDialogManager();
ArrayList<HashMap<String, String>> nameList;

//会话管理器类 // SessionManager会话;

public HomeFragment(){}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_home, container, false);
                   btnViewBars = (Button)rootView.findViewById(R.id.btnViewBars);
          btnNewBar = (Button)rootView.findViewById(R.id.btnCreateBar);


          nameList = new ArrayList<HashMap<String, String>>();

            HashMap<String, String> user = userDetails.getUserDetails();

编辑：

    /**
     * Getting user data from database
     * */
    public HashMap<String, String> getUserDetails(){
        HashMap<String,String> user = new HashMap<String,String>();
        String selectQuery = "SELECT  * FROM " + TABLE_LOGIN;

        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(selectQuery, null);
        // Move to first row
        cursor.moveToFirst();
        if(cursor.getCount() > 0){
         Log.i("key_ID","value is: " + cursor.getString(0));

             Log.i("key_name","value is: " + cursor.getString(1));

             Log.i("key_email","value is: " + cursor.getString(2));
             Log.i("key_uid","value is: " + cursor.getString(3));
             Log.i("key_created_at","value is: " + cursor.getString(4));
           //user.put("name", cursor.getString(1));

//            user.put("email", cursor.getString(2));
//            user.put("uid", cursor.getString(3));
//            user.put("created_at", cursor.getString(4));
        }
        cursor.close();
        db.close();
        // return user
        return user;
    }

Answer 1

创建databaseHandler类的对象

DatabaseHandler db = new DatabaseHandler(MainActivity.this);

现在，获取哈希映射中的用户列表

HashMap<String, String> user=db.getUserDetails();

noe遍历hashmap大小，即使用循环条件并从哈希映射中获取值并在文本视图中设置

user.get(i).get("name")

从sqlite检索数据，在textview中显示名称列

1 个答案: