Android SQlite

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.provider.BaseColumns;

public class UserDbHelper extends SQLiteOpenHelper{
private static final String DATABASE_NAME = "database";
private static final int USER_DATABASE_VISION = 1;
public UserDbHelper(Context context) {
super(context, DATABASE_NAME, null, USER_DATABASE_VISION);
}

@Override
public void onCreate(SQLiteDatabase db) {
String create_table = "create table "+UserColumns.USER_TABLE_NAME+" ("+UserColumns._ID+" integer primary key,"
+UserColumns.IP+" text not null,"+UserColumns.PORT+" text not null,"+UserColumns.NAME+" text not null,"
+UserColumns.IMG+" text not null,"+UserColumns.FALG+" integer not null)";
db.execSQL(create_table);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS "+UserColumns.USER_TABLE_NAME);
onCreate(db);
}

public static final class UserColumns implements BaseColumns{
public UserColumns() {}
public static final String USER_TABLE_NAME = "user";
public static final String IP = "ip";
public static final String PORT = "port";
public static final String NAME = "name";
public static final String IMG = "img";
public static final String FALG = "flag";
}
}

private UserDbHelper userDbHelpser;
private SQLiteDatabase db;
userDbHelpser = new UserDbHelper(this.context);

db = userDbHelpser.getWritableDatabase();
File fileDir;
if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
fileDir = new File(Environment.getExternalStorageDirectory()+"/userImage");
}else{
fileDir = new File(context.getFilesDir()+"/userImage");
}
if(!fileDir.exists()) fileDir.mkdirs();
String fileName = System.currentTimeMillis()+".png";
File imageFile = new File(fileDir.getAbsoluteFile()+"/"+fileName);
OutputStream output = new FileOutputStream(imageFile);
Bitmap bitmap = user.getBitmap();
bitmap.compress(Bitmap.CompressFormat.PNG, 60, output);
ContentValues values = new ContentValues();
values.put(UserColumns._ID, user.getId());
values.put(UserColumns.IP, user.getIp());
values.put(UserColumns.PORT, user.getPort());
values.put(UserColumns.NAME, user.getName());
values.put(UserColumns.IMG, imageFile.getAbsolutePath());
values.put(UserColumns.FALG, user.getFlag());
db.beginTransaction();
long rowId = 0;
try {
db.execSQL("update "+UserColumns.USER_TABLE_NAME+" set "+UserColumns.FALG+"='0'");
rowId = db.insert(UserColumns.USER_TABLE_NAME, null, values);
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}
db.close();