要动态决定要搜索哪些表,可以使用Android Room的查询构建器(Query Builder)来构建动态查询。以下是一个示例代码,演示了如何根据条件动态决定要搜索哪些表:
@Dao
public interface MyDao {
@Query("SELECT * FROM table1")
List getTable1Data();
@Query("SELECT * FROM table2")
List getTable2Data();
}
public class DatabaseManager {
private MyDao myDao;
private boolean searchTable1;
private boolean searchTable2;
public DatabaseManager(MyDao myDao) {
this.myDao = myDao;
}
public void setSearchTables(boolean searchTable1, boolean searchTable2) {
this.searchTable1 = searchTable1;
this.searchTable2 = searchTable2;
}
public List
public class MyActivity extends AppCompatActivity {
private DatabaseManager databaseManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my);
// 初始化数据库管理器
AppDatabase appDatabase = Room.databaseBuilder(getApplicationContext(), AppDatabase.class, "my-database").build();
MyDao myDao = appDatabase.myDao();
databaseManager = new DatabaseManager(myDao);
}
private void performSearch(boolean searchTable1, boolean searchTable2) {
// 设置要搜索的表
databaseManager.setSearchTables(searchTable1, searchTable2);
// 执行查询
List searchData = databaseManager.getData();
// 处理查询结果
// ...
}
}
使用上述代码,你可以根据需要动态决定要搜索哪些表。调用performSearch()
方法时,传入相应的参数来指示是否搜索table1和table2。然后,DatabaseManager
类根据这些参数来执行相应的查询,并返回合并的结果。