Question

i can’t add 2 column in my existing db. i read any topic on the web but i can’t fix my problem. may i have a complete personalized answer to my problem?
naturally i don’t wanna lose existing record, just alter it!
i want to add 2 column (phone (integer), automex (text)) to my db created in this way..

package com.ozzem.mybirthdaylite;



import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;

public class dbMyBirthday {

    SQLiteDatabase db;

    private Context mContext;

    private DbHelper mDbHelper;

     private static final String DB_NAME="dbmyBirthday";
     private static final int DB_VERSION=1;

     //costruttore crea anche il DbHelper
     public dbMyBirthday(Context ctx){
         mContext=ctx;
         mDbHelper=new DbHelper(ctx, DB_NAME, null, DB_VERSION);       
 }


     public void open(){  //il database su cui agiamo è leggibile/scrivibile
         db=mDbHelper.getWritableDatabase();

 }

 public void close(){ //chiudiamo il database su cui agiamo
         db.close();
 }



 public void deletePerson(int idDel){ //metodo per inserire i dati

     String where = "id = " + idDel;
     db.delete(Person.PERSON_TABLE, where,null);
//     Log.d("db_call", "Record of id["+idDel+"] deleted");

}


 public void insertPerson(long l,String name,String birthday){ //metodo per inserire i dati
         ContentValues cv=new ContentValues();
         cv.put(Person.UID, l);
         cv.put(Person.NAME, name);
         cv.put(Person.BIRTHDAY, birthday);

         db.insert(Person.PERSON_TABLE, null, cv);
//         Log.d("db_call", "Record of uid["+uid+"] insered");

 }

 public boolean exist(long uid){
     boolean ex = false;

     Cursor c= db.rawQuery("SELECT COUNT(*) FROM " + Person.PERSON_TABLE + " WHERE uid = "+ "'" + uid + "'", null);
        c.moveToFirst();
      int jcount = c.getInt(0);

      if (jcount >0){
        ex=true;            
    }
     return ex;
 }



 public void updatePersonFromId(int id,String name,String birthday){

     ContentValues cv=new ContentValues();
//   cv.put(Person.UID, id);
     cv.put(Person.NAME, name);
     cv.put(Person.BIRTHDAY, birthday);

     String where = "id = " + "'"+id+"'";
     db.update(Person.PERSON_TABLE, cv, where, null);
//     Log.d("db_call", "Record of id["+id+"] updated");

 }

 public void updatePersonFromUid(long l,String name,String birthday){

     ContentValues cv=new ContentValues();
     cv.put(Person.UID, l);
     cv.put(Person.NAME, name);
     cv.put(Person.BIRTHDAY, birthday);

     String where = "uid = " + "'"+l+"'";
     db.update(Person.PERSON_TABLE, cv, where, null);
//     Log.d("db_call", "Record of uid["+uid+"] updated");

 }

 public Cursor fetchAllBirthday(){ //metodo per fare la query di tutti i dati
//   Log.d("db_call", "Fetching all birthdays");    
     return db.query(Person.PERSON_TABLE, null,null,null,null,null,null);               
 }

 public static class Person {  // i metadati della tabella, accessibili ovunque

        static final String PERSON_TABLE = "person";
         static final String ID = "id";
         static final String UID = "uid";
         static final String NAME = "name";
         public static final String BIRTHDAY = "birthday";

 }

 private static final String PERSON_TABLE_CREATE = "CREATE TABLE IF NOT EXISTS "  //codice sql di creazione della tabella

                + Person.PERSON_TABLE + " (" 
                 + Person.ID + " integer primary key autoincrement, "
                 + Person.NAME + " text not null, "
                 + Person.UID + " integer not null, "
                 + Person.BIRTHDAY + " text not null );";



     private class DbHelper extends SQLiteOpenHelper { //classe che ci aiuta nella creazione del db

         public DbHelper(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(PERSON_TABLE_CREATE);


    }

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

    }

}
}

Answer 1

Increase DB_Version to 2 then in your OnUpgrade override of your OpenHelper run your upgrade code

e.g:

    if (oldVersion==1 && newVersion==2) {
      db.execSQL("ALTER TABLE " + TableName + " ADD COLUMN " + ColumnName1);
      db.execSQL("ALTER TABLE " + TableName + " ADD COLUMN " + ColumnName2);
    }

Also modify your inital code so that the new field is created at the same time as the table for those who do not have a version 1 database to upgrade. i.e Those who create a version 2 database first.