// 获取可读数据库
SQLiteDatabase db = dbHelper.getReadableDatabase();

// 定义查询参数
String table = "users";
String[] columns = {"id", "name", "age"};
String selection = "age > ? AND name = ?"; // WHERE条件
String[] selectionArgs = {"18", "John"};   // 替换?的参数值
String groupBy = null;
String having = null;
String orderBy = "name ASC";
String limit = "10";

// 执行查询
Cursor cursor = db.query(
    table, 
    columns, 
    selection, 
    selectionArgs, 
    groupBy, 
    having, 
    orderBy, 
    limit
);

// 处理结果
while (cursor.moveToNext()) {
    int id = cursor.getInt(cursor.getColumnIndex("id"));
    String name = cursor.getString(cursor.getColumnIndex("name"));
    int age = cursor.getInt(cursor.getColumnIndex("age"));
    // 使用数据...
}

// 关闭cursor和db
cursor.close();
db.close();

// 定义DAO接口
@Dao
public interface UserDao {
    @Query("SELECT * FROM users WHERE age > :minAge AND name = :name")
    List<User> getUsersOlderThanByName(int minAge, String name);
    
    // 动态查询
    @Query("SELECT * FROM users WHERE name LIKE :search OR age > :minAge")
    List<User> findUsers(String search, int minAge);
}

// 使用DAO
UserDao userDao = db.userDao();
List<User> users = userDao.getUsersOlderThanByName(18, "John");