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我在android中製作了一個信息系統，首次登錄後，它要求用戶顯示員工列表並添加新員工。所以問題是如何使用不同的表來存儲員工的信息並在列表視圖中顯示在其他活動中。這是我的代碼在SQLite數據庫中使用多個表android
這是數據庫的適配器類。
公共類LoginDataBaseAdapter {
static final String DATABASE_NAME = "login.db";
static final int DATABASE_VERSION = 1;
public static final int NAME_COLUMN = 1;
static final String DATABASE_CREATE = "create table "+"LOGIN"+
"(" +"ID"+" integer primary key autoincrement,"+ "USERNAME text,PASSWORD text); ";
public SQLiteDatabase db;
private final Context context;
private DbHelper dbHelper;
public LoginDataBaseAdapter(Context _context)
{
context = _context;
dbHelper = new DbHelper(context, DATABASE_NAME, null, DATABASE_VERSION);
}
public LoginDataBaseAdapter open() throws SQLException
{
db = dbHelper.getWritableDatabase();
return this;
}
public void close()
{
db.close();
}
public SQLiteDatabase getDatabaseInstance()
{
return db;
}
public void insertEntry(String userName,String password)
{
ContentValues newValues = new ContentValues();
newValues.put("USERNAME", userName);
newValues.put("PASSWORD",password);
db.insert("LOGIN", null, newValues);
}
public int deleteEntry(String UserName)
{
String where="USERNAME=?";
int numberOFEntriesDeleted= db.delete("LOGIN", where, new String[]{UserName}) ;
return numberOFEntriesDeleted;
}
public String getSinlgeEntry(String userName)
{
Cursor cursor=db.query("LOGIN", null, " USERNAME=?", new String[]{userName}, null, null, null);
if(cursor.getCount()<1) // UserName Not Exist
{
cursor.close();
return "NOT EXIST";
}
cursor.moveToFirst();
String password= cursor.getString(cursor.getColumnIndex("PASSWORD"));
cursor.close();
return password;
}
public void updateEntry(String userName,String password)
{
ContentValues updatedValues = new ContentValues();
updatedValues.put("USERNAME", userName);
updatedValues.put("PASSWORD",password);
String where="USERNAME = ?";
db.update("LOGIN",updatedValues, where, new String[]{userName});
}
}
這是輔助類。
公共類DbHelper擴展SQLiteOpenHelper {
public DbHelper(Context context, String name, CursorFactory factory,
int version) {
super(context, name, factory, version);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase _db) {
// TODO Auto-generated method stub
_db.execSQL(LoginDataBaseAdapter.DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase _db, int _oldVersion, int _newVersion) {
// TODO Auto-generated method stub
Log.w("TaskDBAdapter", "Upgrading from version " + _oldVersion + " to " + _newVersion + ", which will destroy all old data");
_db.execSQL("DROP TABLE IF EXISTS " + "TEMPLATE");
onCreate(_db);
}
}