从 SQLite (Android) 对列项进行分组

Question

我有一系列列表视图，这些列表视图是根据手机上 SQLite 数据库中存储的数据生成的。假设表格如下所示：

__________________________________________
|   ID   |     X    |    Y    |     Z    | 
|________|__________|_________|__________| 
|   1    |   ABC    |   123   |   B94    | 
|   2    |   ABC    |   234   |   C33    | 
|   3    |   DEF    |   567   |   N72    | 
|   4    |   DEF    |   789   |   K12    |  
|________|__________|_________|__________|...

我想从“X”列创建一个列表视图，单击时会在“Y”列中打开与新列表视图中的行相关联的数据。棘手的部分是我想在他们的列表视图中将每列中的相同项目组合在一起。在此示例中，第一个列表视图将只有两个项目“ABC;DEF”，当单击“ABC”时，它将在下一个列表视图中显示“123;234”项目。

这是我的代码（是的，我在教程中修改了大部分代码！）：

listviewactivity.java

public class listviewactivity extends Activity {    
private SQLiteAdapter mySQLiteAdapter;
 ListView listContent;   
 SimpleCursorAdapter cursorAdapter;
 Cursor cursor;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.expenses);
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

    listContent = (ListView)findViewById(R.id.contentlist);
    mySQLiteAdapter = new SQLiteAdapter(this);
    mySQLiteAdapter.openToWrite();        

    cursor = mySQLiteAdapter.queueAll();
    String[] from = new String[]{SQLiteAdapter.KEY_ID, SQLiteAdapter.KEY_CONTENT1, SQLiteAdapter.KEY_CONTENT2};
    int[] to = new int[]{R.id.id, R.id.text1, R.id.text2};
    cursorAdapter =
     new SimpleCursorAdapter(this, R.layout.row, cursor, from, to);
    listContent.setAdapter(cursorAdapter);    


}

 @Override
 protected void onDestroy() {
  // TODO Auto-generated method stub
  super.onDestroy();
  mySQLiteAdapter.close();
 }
}

SQLiteAdapter.java

public class SQLiteAdapter {
public static final String MYDATABASE_NAME = "MY_DATABASE";
public static final String MYDATABASE_TABLE = "MY_TABLE";
public static final int MYDATABASE_VERSION = 1;
public static final String KEY_ID = "_id";
public static final String KEY_CONTENT1 = "Content1";
public static final String KEY_CONTENT2 = "Content2";
public static final String KEY_CONTENT3 = "Content3"; 
public static final String KEY_CONTENT4 = "Content4"; 
public static final String KEY_CONTENT5 = "Content5"; 
public static final String KEY_CONTENT6 = "Content6"; 
public static final String KEY_CONTENT7 = "Content7"; 
public static final String KEY_CONTENT8 = "Content8";

private static final String SCRIPT_CREATE_DATABASE =
 "create table " + MYDATABASE_TABLE + " ("
 + KEY_ID + " integer primary key autoincrement, "
 + KEY_CONTENT1 + " text not null, "
 + KEY_CONTENT2 + " text not null,"  
 + KEY_CONTENT3 + " text not null, "
 + KEY_CONTENT4 + " text not null,"   
 + KEY_CONTENT5 + " text not null, "
 + KEY_CONTENT6 + " text not null,"   
 + KEY_CONTENT7 + " text not null,"  
 + KEY_CONTENT8 + " text not null);"; 

private SQLiteHelper sqLiteHelper;
private SQLiteDatabase sqLiteDatabase;
private Context context;
public SQLiteAdapter(Context c){

 context = c;

} 

public SQLiteAdapter openToRead() throws android.database.SQLException {
 sqLiteHelper = new SQLiteHelper(context, MYDATABASE_NAME, null, MYDATABASE_VERSION);
 sqLiteDatabase = sqLiteHelper.getReadableDatabase();
 return this; 

} 

public SQLiteAdapter openToWrite() throws android.database.SQLException {
 sqLiteHelper = new SQLiteHelper(context, MYDATABASE_NAME, null, MYDATABASE_VERSION);
 sqLiteDatabase = sqLiteHelper.getWritableDatabase();
 return this; 

}

public void close(){
sqLiteHelper.close();
} 

public long insert(String content1, String content2, String content3,
                String content4, String content5, String content6, 
                           String content7, String content8){

 ContentValues contentValues = new ContentValues();
 contentValues.put(KEY_CONTENT1, content1);
 contentValues.put(KEY_CONTENT2, content2);  
 contentValues.put(KEY_CONTENT3, content3);  
 contentValues.put(KEY_CONTENT4, content4);  
 contentValues.put(KEY_CONTENT5, content5);  
 contentValues.put(KEY_CONTENT6, content6);  
 contentValues.put(KEY_CONTENT7, content7);
 contentValues.put(KEY_CONTENT8, content8);

 return sqLiteDatabase.insert(MYDATABASE_TABLE, null, contentValues);
} 

public int deleteAll(){
 return sqLiteDatabase.delete(MYDATABASE_TABLE, null, null);
}
public Cursor queueAll(){
 String[] columns = new String[]{KEY_ID, KEY_CONTENT1, KEY_CONTENT2, KEY_CONTENT3,
                              KEY_CONTENT4, KEY_CONTENT5, KEY_CONTENT6, 
                                        KEY_CONTENT7, KEY_CONTENT8};

 Cursor cursor = sqLiteDatabase.query(MYDATABASE_TABLE, columns,
 null, null, null, null, null, null);
   return cursor;

} 

 public class SQLiteHelper extends SQLiteOpenHelper {
public SQLiteHelper(Context context, String name,
CursorFactory factory, int version) {
super(context, name, factory, version);

}

@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL(SCRIPT_CREATE_DATABASE);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
 // TODO Auto-generated method stub   
    }

  } 

}

所以这基本上只是将一堆信息存储在一个表中，该表通过光标加载到列表视图中。如果有人可以帮助我处理我的 OnItemClickListener 或将列项分组在一起，那就太棒了！

Answer 1

您必须设置一个新的 listadaper，将结果限制为 ABC 的所有内容

例如：

Cursor c = sqlLiteDatabase.query(MYDATABASE_TABLE,
new String[] {KEY_ID,COLUMN_Y},
COLUMN_X + "=" + ITEM_IN_COLUMN_X_CLICKED,
null,null,null);

关键是查询中的where，你想查询所有被点击的项目，即。 COLUMN_X + "=" + ITEM_IN_COLUMN_X_CLICKED。

因此，如果您单击ABC，新列表将显示column y 中的所有内容以及ABC 中的ABCcolumn x