具有相同結構的多個表 - Sqlite

Question

我有一個名爲Messages.But的表，我想爲單獨的用戶創建一個單獨的表。 例如： 如果我的用戶名是Ciddarth 我想要一個名爲Ciddarth具有相同的結構，消息

public class DbHandler extends SQLiteOpenHelper { 

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

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

// Contacts table name 
private String TABLE_MESSAGES = "Messages"; 

// Contacts Table Columns names 
private static final String KEY_ID = "id"; 
private static final String KEY_MESSAGE = "message"; 
private static final String KEY_SEND = "send"; 
private static final String KEY_STATUS = "status"; 
private static final String KEY_TIME = "time"; 

public DbHandler(Context context) { 
    super(context, DATABASE_NAME, null, DATABASE_VERSION); 
    //TABLE_MESSAGES=name; 
} 

// Creating Tables 
@Override 
public void onCreate(SQLiteDatabase db) { 
    this.db=db; 
    String CREATE_MESSAGE_TABLE = "CREATE TABLE " + TABLE_MESSAGES + "(" 
      + KEY_ID + " INTEGER PRIMARY KEY," + KEY_MESSAGE + " MEDIUMTEXT," 
      + KEY_SEND + " TEXT," + KEY_STATUS + " INTEGER,"+KEY_TIME+" DATETIME DEFAULT (DATETIME(CURRENT_TIMESTAMP, 'LOCALTIME'))"+")"; 
    db.execSQL(CREATE_MESSAGE_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_MESSAGES); 

    // Create tables again 
    onCreate(db); 
} 

/** 
* All CRUD(Create, Read, Update, Delete) Operations 
*/ 

// Adding new contact 
void addMessage(Message message) { 
    SQLiteDatabase db = this.getWritableDatabase(); 

    ContentValues values = new ContentValues(); 
    values.put(KEY_MESSAGE, message.getMessage()); 
    values.put(KEY_SEND, message.getSend()); 
    values.put(KEY_STATUS, message.getStatus()); 

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

// Getting single contact 
Message getMessage(int id) { 
    SQLiteDatabase db = this.getReadableDatabase(); 

    Cursor cursor = db.query(TABLE_MESSAGES, new String[] { KEY_ID, 
        KEY_MESSAGE, KEY_SEND }, KEY_ID + "=?", 
      new String[] { String.valueOf(id) }, null, null, null, null); 
    if (cursor != null) 
     cursor.moveToFirst(); 

    Message message = new Message(Integer.parseInt(cursor.getString(0)), 
      cursor.getString(1), cursor.getString(2),cursor.getString(4),Integer.parseInt(cursor.getString(3))); 
    return message; 

} 

// Getting All Contacts 
public List<Message> getAllContacts() { 
    List<Message> msgList = new ArrayList<Message>(); 
    // Select All Query 
    String selectQuery = "SELECT * FROM " + TABLE_MESSAGES; 

    SQLiteDatabase db = this.getWritableDatabase(); 
    Cursor cursor = db.rawQuery(selectQuery, null); 

    // looping through all rows and adding to list 
    if (cursor.moveToFirst()) { 
     do { 
      Message message = new Message(); 
      message.setID(Integer.parseInt(cursor.getString(0))); 
      message.setMessage(cursor.getString(1)); 
      message.setSend(cursor.getString(2)); 
      message.setStatus(cursor.getInt(3)); 
      message.setTime(cursor.getString(4)); 
      // Adding contact to list 
      msgList.add(message); 
     } while (cursor.moveToNext()); 
    } 

    // return contact list 
    return msgList; 
} 

// Updating single contact 
public int updateMessage(Message message) { 
    SQLiteDatabase db = this.getWritableDatabase(); 

    ContentValues values = new ContentValues(); 
    values.put(KEY_MESSAGE, message.getMessage()); 
    values.put(KEY_SEND, message.getSend()); 

    // updating row 
    return db.update(TABLE_MESSAGES, values, KEY_ID + " = ?", 
      new String[] { String.valueOf(message.getID()) }); 
} 

// Deleting single contact 
public void deleteMessage(int id) { 
    SQLiteDatabase db = this.getWritableDatabase(); 
    db.delete(TABLE_MESSAGES, KEY_ID + " = ?", 
      new String[] { String.valueOf(id) }); 
    db.close(); 
} 


// Getting contacts Count 
public int getMessageCount() { 
    String countQuery = "SELECT * FROM " + TABLE_MESSAGES; 
    SQLiteDatabase db = this.getReadableDatabase(); 
    Cursor cursor = db.rawQuery(countQuery, null); 
    cursor.close(); 

    // return count 
    return cursor.getCount(); 
} 

public void deleteAll() 
{ 
    SQLiteDatabase db = this.getWritableDatabase(); 
    db.execSQL("delete from "+ TABLE_MESSAGES); 
    db.close(); 
} 

public void deleteTable() 
{ 
    SQLiteDatabase db = this.getReadableDatabase(); 
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_MESSAGES); 
    db.close(); 
} 

public void changeStatus(int status,int id) 
{ 
    SQLiteDatabase db = this.getWritableDatabase(); 
    ContentValues cv = new ContentValues(); 
    cv.put(KEY_STATUS,status); 
    db.update(TABLE_MESSAGES, cv, "id="+id, null); 
    db.close(); 
} 
} 

現在我想改變與用戶如何我這樣做的TABLES_MESSAGES表？ 如果我將TABLE_MESSAGES的值更改爲Ciddarth，它仍然不起作用。

Answer 1

做一個單獨的方法...

`createNewTable(String tablename){ 
    SqliteOpenDatabase db = this.getWriteableDatabase(); 
    String CREATE_MESSAGE_TABLE = "CREATE TABLE " + tablename + "(" 
     + KEY_ID + " INTEGER PRIMARY KEY," + KEY_MESSAGE + " MEDIUMTEXT," 
     + KEY_SEND + " TEXT," + KEY_STATUS + " INTEGER,"+KEY_TIME+ 
     "DATETIME DEFAULT (DATETIME(CURRENT_TIMESTAMP, 'LOCALTIME'))"+")"; 
db.execSQL(CREATE_MESSAGE_TABLE);` 

，並添加String tablename到其他CRUD方法。

編輯：忘了this.getWritableDatabase（）;