public DbHelper(Context context, String name, int version){
  this(context, name, null, version);
}

try {
  ver=getVersionName(getApplicationContext());
} catch (Exception e) {
  e.printStackTrace();
}
myDbHelper = new DbHelper(this,DbHelper.DB_NAME,ver);
db= myDbHelper.getWritableDatabase();

getWritableDatabase()

getDatabaseLocked(boolean writable)

final int version = db.getVersion();
if (version != mNewVersion) {
  if (db.isReadOnly()) {
    throw new SQLiteException("Can't upgrade read-only database from version " +
        db.getVersion() + " to " + mNewVersion + ": " + mName);
  }
  db.beginTransaction();
  try {
    if (version == 0) {
      onCreate(db);
    } else {
      if (version > mNewVersion) {
        onDowngrade(db, version, mNewVersion);
      } else {
        onUpgrade(db, version, mNewVersion);
      }
    }
    db.setVersion(mNewVersion);
    db.setTransactionSuccessful();
  } finally {
    db.endTransaction();
  }

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
  if(newVersion>oldVersion)
  {
    db.execSQL("ALTER TABLE local_picc_talk ADD talknumber varchar(20);");
  }
}

select * from sqlite_master where type="table" and name="local_picc_talk";
table|local_picc_talk|local_picc_talk|9|CREATE TABLE local_picc_talk (id integer
 PRIMARY KEY autoincrement,case_no varchar(60),user_no varchar(60),user_name var
char(60),car_no varchar(60),task_work_id varchar(60),talk_content varchar(1000),
time varchar(60),with_talk_no varchar(60),with_talk_name varchar(60), talknumber
 varchar(20), UNIQUE (id))
sqlite> select * from local_picc_talk;