我已经尝试查看有关此主题的几个已经提出的问题,但我仍然无法让我的文件正常工作。我想也许一些直接的直接帮助可能正是我所需要的,所以我谦虚地向社区寻求帮助。感谢您的时间
public class RemindersDbAdapter {
//
// Database Related Constants
//
private static final String DATABASE_NAME = "data";
private static final String DATABASE_TABLE = "reminders";
private static final int DATABASE_VERSION = 3;
public static final String KEY_TITLE = "title";
public static final String KEY_CUSTOMER = "body";
public static final String KEY_DATE_TIME = "reminder_date_time";
public static final String KEY_END_TIME = "reminder_end_time";
public static final String KEY_ROWID = "_id";
private static final String TAG = "ReminderDbAdapter";
private DatabaseHelper mDbHelper;
private static SQLiteDatabase mDb;
/**
* Database creation SQL statement
*/
private static final String DATABASE_CREATE =
"create table " + DATABASE_TABLE + " ("
+ KEY_ROWID + " integer primary key autoincrement, "
+ KEY_TITLE + " text not null, "
+ KEY_CUSTOMER + " text not null, "
+ KEY_DATE_TIME + " text not null);" ;
private final Context mCtx;
private static class DatabaseHelper extends SQLiteOpenHelper
{
DatabaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db)
{
db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
//Adding a Column
// If you need to add a column
if (newVersion > oldVersion)
{
//example I tried pulling from the internet
db.execSQL(
"ALTER TABLE foo ADD COLUMN new_column INTEGER DEFAULT 0");
}
onCreate(db);
}
}