在Android sq-lite数据库中添加新列

Question

我的逻辑是：

只需在按钮点击时将数据插入sqlite数据库。我已创建并且工作正常。

我的要求是：

我想再向现有的Sqlite添加一列，所以我手动添加。

我做的是我删除了模拟器中的现有表并运行我的代码，我有查询来创建一个新表。执行代码表没有得到创建

这是我的代码：

此处User_Id是我的新列在sq-lite DB

中

MainActivity.java

    @Override
    public void onClick(View v) {
            Flag="I";
        if (valid_JobNo != null 
        && valid_Status != null
        && valid_Date_Time != null 
        && valid_User_Id != null

        &&valid_JobNo.length() != 0
        && valid_Status.length() != 0
        && valid_Date_Time.length() != 0
       &&valid_User_Id.length() != 0
        && Flag.length()!=0)
        {

        flagL = "T";
        dbHandler.Add_Tracking(new Tracking(valid_JobNo,
        valid_Status, valid_Date_Time,valid_User_Id,flagL));
        Toast_msg = "Not Connected To Internet.\nData inserted in Sqlite DB successfully";
        Show_Toast(Toast_msg);
        Reset_Text();

        }
        else
        {
            Toast_msg = "Sorry Some Fields are missing.\nPlease Fill up all.";
            Show_Toast(Toast_msg);
        }

DB Handler .java

private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "Cargonet";
private static final String TABLE_Tracking = "CargoTracking";

private static final String KEY_ID = "id";
private static final String KEY_JobNo = "JobNo";
private static final String KEY_Status = "Status";
private static final String KEY_User_Id = "User_Id";
private static final String KEY_Flag = "Flag";
private static final String KEY_Date_Time = "Date_Time";
private final ArrayList<Tracking> Tracking_list = new ArrayList<Tracking>();

public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_Tracking_TABLE = "CREATE TABLE " + TABLE_Tracking + "("
    + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," + KEY_JobNo + " TEXT,"
    + KEY_Status + " TEXT," + KEY_User_Id + " TEXT," + KEY_Date_Time + " TEXT," + KEY_Flag + " TEXT "+ ")";
db.execSQL(CREATE_Tracking_TABLE);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_Tracking);
// Create tables again
onCreate(db);
}

public void Add_Tracking(Tracking Tracking) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_JobNo, Tracking.getJobNo()); // Tracking JobNo
values.put(KEY_Status, Tracking.getStatus());
values.put(KEY_User_Id, Tracking.getUser_Id());
values.put(KEY_Flag, Tracking.getFlag());// Tracking Phone
values.put(KEY_Date_Time, Tracking.getDate_Time());
// Inserting Row
db.insert(TABLE_Tracking, null, values);
db.close(); // Closing database connection
}

Tracking Get_Tracking(int id) {
SQLiteDatabase db = this.getReadableDatabase();

Cursor cursor = db.query(TABLE_Tracking, new String[] { KEY_ID,
    KEY_JobNo, KEY_Status, KEY_Date_Time ,KEY_User_Id, KEY_Flag}, KEY_ID + "=?",
    new String[] { String.valueOf(id) }, null, null, null, null);
if (cursor != null)
    cursor.moveToFirst();

Tracking Tracking = new Tracking(Integer.parseInt(cursor.getString(0)),
    cursor.getString(1), cursor.getString(2), cursor.getString(3), cursor.getString(4),(cursor.getString(5)));
// return Tracking
cursor.close();
db.close();

return Tracking;
}

Tracking Get_TrackingF(String Flag) {
    SQLiteDatabase db = this.getReadableDatabase();

    Cursor cursor = db.query(TABLE_Tracking, new String[] { KEY_ID,
        KEY_JobNo, KEY_Status, KEY_Date_Time ,KEY_User_Id, KEY_Flag}, KEY_Flag + "=?",
        new String[] { String.valueOf(Flag) }, null, null, null, null);
    if (cursor != null)
        cursor.moveToFirst();

    Tracking Tracking = new Tracking(Integer.parseInt(cursor.getString(0)),
        cursor.getString(1), cursor.getString(2), cursor.getString(3), cursor.getString(4), (cursor.getString(5)));
    // return Tracking
    cursor.close();
    db.close();

    return Tracking;
    }

public ArrayList<Tracking> Get_Tracking() {
try {
    Tracking_list.clear();

    String selectQuery = "SELECT  * FROM " + TABLE_Tracking;

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

    if (cursor.moveToFirst()) {
    do {
        Tracking Tracking = new Tracking();
        Tracking.setID(Integer.parseInt(cursor.getString(0)));

        Tracking.setJobNo(cursor.getString(1));
        Tracking.setStatus(cursor.getString(2));
        Tracking.setDate_Time(cursor.getString(3));
        Tracking.setUser_Id(cursor.getString(4));
        Tracking.setFlag(cursor.getString(5));
        // Adding Tracking to list
        Tracking_list.add(Tracking);
    } while (cursor.moveToNext());
    }

    cursor.close();
    db.close();
    return Tracking_list;
} catch (Exception e) {
    // TODO: handle exception
    Log.e("all_Tracking", "" + e);
}

return Tracking_list;
}

public int Update_Tracking(Tracking Tracking) {
SQLiteDatabase db = this.getWritableDatabase();

ContentValues values = new ContentValues();
values.put(KEY_JobNo, Tracking.getJobNo());
values.put(KEY_Status, Tracking.getStatus());
values.put(KEY_Date_Time, Tracking.getDate_Time());
values.put(KEY_User_Id, Tracking.getUser_Id());
values.put(KEY_Flag, Tracking.getFlag());

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

public void Delete_Tracking(int id) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_Tracking, KEY_ID + " = ?",
    new String[] { String.valueOf(id) });
db.close();
}

public int Get_Total_Tracking(Tracking Tracking) {
String countQuery = "SELECT  * FROM " + TABLE_Tracking;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
cursor.close();

return cursor.getCount();
}

Tracking Get_Flag(String flag) {
SQLiteDatabase db = this.getReadableDatabase();

Cursor cursor = db.query(TABLE_Tracking, new String[] { KEY_ID,
    KEY_JobNo, KEY_Status, KEY_Date_Time ,KEY_User_Id , KEY_Flag}, KEY_Flag + "=?",
    new String[] { String.valueOf(flag) }, null, null, null, null);
if (cursor != null)
    cursor.moveToFirst();

Tracking Tracking = new Tracking(Integer.parseInt(cursor.getString(0)),
    cursor.getString(1), cursor.getString(2), cursor.getString(3), cursor.getString(4) , (cursor.getString(5)));
    cursor.close();
db.close();

return Tracking;
}
public Cursor getListItem() {
    // TODO Auto-generated method stub
    return null;
}
public void addListItem(ArrayList<String> tracking_data) {
    // TODO Auto-generated method stub
}

}

Tracking.java

public class Tracking {

// private variables
public int _id;
public String _JobNo;
public String _Status;
public String _Flag;
public String _Date_Time;
public String _User_Id;

public Tracking() {
}

public Tracking(int id, String JobNo, String _Status, String _Date_Time,String _User_Id, String _Flag) {
this._id = id;
this._JobNo = JobNo;
this._Status = _Status;
this._Date_Time = _Date_Time;
this._User_Id = _User_Id;
this._Flag = _Flag;
}

public Tracking(String JobNo, String _Status, String _Date_Time,String _User_Id, String _Flag) {
this._JobNo = JobNo;
this._Status = _Status;
this._Date_Time = _Date_Time;
this._User_Id = _User_Id; 
this._Flag = _Flag;
}

public int getID() {
return this._id;
}

public void setID(int id) {
this._id = id;
}

public String getJobNo() {
return this._JobNo;
}

public void setJobNo(String JobNo) {
this._JobNo = JobNo;
}

public String getStatus() {
return this._Status;
}

public void setStatus(String Status) {
this._Status = Status;
}

public String getDate_Time() {
return this._Date_Time;
}

public void setDate_Time(String Date_Time) {
this._Date_Time = Date_Time;
}

public String getUser_Id() {
return this._User_Id;
}

public void setUser_Id(String User_Id) {
this._User_Id = User_Id;
}

public String getFlag() {
    return this._Flag;
    }

public void setFlag(String Flag) {
    this._Flag = Flag;
    }
}

Answer 1

我已经浏览了大部分代码，但我认为你真正要问的是＆＃34;你如何更新数据库？＆＃34;

首先，您将更改public void onCreate(SQLiteDatabase db)函数，以使用要添加的新列创建模型数据库结构。然后将DATABASE_VERSION = 1更改为DATABASE_VERSION = 2。如果新版本大于当前版本，则再次运行删除表和onCreate功能。

此外，关于public void Add_Tracking(Tracking Tracking)的旁注将其更改为public void Add_Tracking(Tracking tracking)，并将对该变量的所有引用也更改为以小写字母开头。我不确定这是否会导致您的代码出现任何问题，但当局部变量和类具有相同的名称和格式时，它会让人感到困惑。

Answer 2

不清楚您的问题是什么或您想要选择添加新列的选项，但通常是添加新列您必须检查数据库版本并升级它并添加新列。你可以在onUpgrade（）：

中完成

     @Override
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

       // If you need to add a new column
        if (newVersion > oldVersion) {
             db.execSQL("ALTER TABLE "+table_name+" ADD COLUMN "+new_column_name + "  INTEGER DEFAULT 0");
         }
     }

而不是整数默认值0，您还可以使用TEXT NOT NULL或任何其他值您想要放入数据库列。