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I need suggestion about send data between remote db server and android local sqlite data

I am working in android app project in which I am storing data into a local db which is sqlite for store data offline.Data size is minimal which is basically like name,mobile no etc.I store those data into sqlite because i consider that app client don't have internet connection or he store multiple data so he can store data locally,and the next part is send data into a sql server with a button click.I can't work with synchronization because of sql server (Central remote server) have lot's of table and lot's data,i don't want to rush my local android app db.I am tryed to fetch data with while loop and then fetch data from sqlite and then send data sql server directly(i don't use api because security is not a concern here)
enter code here
package com.ohnnu.myofficetool;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
/**
* Created by joy on 11/4/2016.
*/
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME="myofficetool.db";
public static final String TABLE_NAME="orderChalan_table";
public static final String COL_1="ID";
public static final String COL_2="ProdNo";
public static final String COL_3="Qtn";
public static final String COL_4="CusID";
public String delete;
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, 1);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table "+TABLE_NAME+"(ID INTEGER PRIMARY KEY AUTOINCREMENT,ProdNo TEXT,Qtn TEXT,CusID TEXT)");
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS "+TABLE_NAME);
onCreate(db);
}
}
public Cursor getAllData(){
SQLiteDatabase db=this.getWritableDatabase();
Cursor res=db.rawQuery("select * from "+TABLE_NAME,null);
return res;
}
}
What i am trying now to fetch information in asynctask after that send the fetch data into sql server.Please suggest me how to fetch information in aynctask,

you need to use webservices to send data to webserver.

Reference generated code in Java

I'm creating an android application. I'm using schematic to generate a content provider.
I understand that the actual code used by the application is generated out of the classes I create. Based on that, I'd like to know what problems I will face if I reference the generated code in the source code.
The code I'm using is the following:
package com.example.movies.data;
#Database(
version = MovieDatabase.VERSION,
packageName = "com.example.movies.provider"
)
public class MovieDatabase {
public static final int VERSION = 1;
#Table(MovieColumns.class)
public static final String MOVIE = "movie";
// Some more tables here
#OnUpgrade
public static void onUpgrade(Context context, SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("drop table if exists " + MOVIE);
// The next SQL statement is generated out of the current class
db.execSQL(com.example.movies.provider.MovieDatabase.MOVIE);
}
}
The generated code is next:
package com.example.movies.provider;
public class MovieDatabase extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
// The next statement is the one I use in the source code
public static final String MOVIE = "CREATE TABLE movie ("
+ MovieColumns._ID + " INTEGER PRIMARY KEY,"
+ MovieColumns.TITLE + " TEXT NOT NULL,"
+ MovieColumns.SYNOPSIS + " TEXT,"
+ MovieColumns.POSTER_URL + " TEXT NOT NULL,"
+ MovieColumns.RELEASE_DATE + " INTEGER NOT NULL,"
+ MovieColumns.RATING + " REAL)";
// Some other SQL statements and functions
// The next function is generated out of onUpgrade
// in the source class MovieDatabase
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
com.example.movies.data.MovieDatabase.onUpgrade(context, db, oldVersion, newVersion);
}
}
As you can see, I need the SQL statements generated by the source code, and the idea of using the mentioned library is to avoid all the boilerplate code.
Are there other alternatives?

Slightly better approach would be:
#OnUpgrade
public static void onUpgrade(Context context, SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("drop table if exists " + MOVIE);
// The next SQL statement is generated out of the current class
com.example.movies.provider.MovieDatabase.getInstance(context).onCreate(db);
}
At least you do not need to specify each table.
Based on that, I'd like to know what problems I will face if I reference the generated code in the source code.
I would say no real problems.
The only noticeable thing is that Android Studio will highlight this as compilation error until class is generated (during the first build).

Android SQLite onUpgrade not called

I have my database created in event onCreate, in which I have a lot of tables, but I need add 1 more table, and I can't lose any data, So I need to use the event onUpgrade, So I hope you guys help me because I don't know how to use it.
Example :
public void onCreate(SQLiteDatabase db) {
sql = "CREATE TABLE IF NOT EXISTS funcionarios"
+"(codigo INTEGER PRIMARY KEY, funcionario TEXT, apelido TEXT , functionTEXT, cartao TEXT , foto TEXT , tipo_foto TEXT);";
db.execSQL(sql);
}
what i need is
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if(oldVersion < 2){
db.execSQL("CREATE TABLE IF NOT EXISTS calibrar_aceleracao"+
"(limiteMaximo INTEGER, limiteMinimo INTEGER);");
}
}
but it doesn't work.
thanks.

You do not need to change you applications version to update your database - not saying it is incorrect but there is a more efficient way of doing it. And that is through the use of the super's constructor of your helper it would look something like the following:
public class MyDatabaseHelper extends SQLiteOpenHelper {
public MyDatabaseHelper(Context context) {
super(context, "My.db", null, 1 /* This is the version of the database*/);
}
#Override
public void onCreate(SQLiteDatabase database) {
sql = "CREATE TABLE IF NOT EXISTS funcionarios (codigo INTEGER PRIMARY KEY, funcionario TEXT, apelido TEXT , functionTEXT, cartao TEXT , foto TEXT , tipo_foto TEXT);";
db.execSQL(sql);
}
#Override
public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) {
if(oldVersion < 2){
db.execSQL("CREATE TABLE IF NOT EXISTS calibrar_aceleracao (limiteMaximo INTEGER, limiteMinimo INTEGER);");
}
}
}

The method onUpgrade is called when your version database is incremented. Verify in your class where you define your database version and increment this value.
Run application. Your method onUpgrade is called.

For onUpgrade to get called you must increase the database version that you supply to the SqliteOpenHelper implementation constructor.
Use a field in your class to store the same and increment it when you change your database schema.

This is not the way onUpgrade works.This is a method which will be called when you release some new version of your application and make it available for download in google play(and which may be requiring some updations to the database of the application already installed on users' devices').For your problem's solution
Just add the query of CREATE TABLE IF NOT EXISTS in your onCreate() as you did for the creation of the other table in your onCreate() method already
public void onCreate(SQLiteDatabase db) {
sql = "CREATE TABLE IF NOT EXISTS funcionarios"
+"(codigo INTEGER PRIMARY KEY, funcionario TEXT, apelido TEXT , functionTEXT, cartao TEXT , foto TEXT , tipo_foto TEXT);";
///HERE YOUR Create Table QUERY and call db.execSQL
db.execSQL(sql);
}

The method is onUpgrade is not being called probably because there are errors in the sql code, for example in the onCreate:
functionTEXT
is missing a space before TEXT.
Also after,
calibrar_aceleracao"+ "(limiteMaximo
is missing a space before the bracket.
I had the same problem, I was caching the SQLiteException so I didn't see the error was there.
Put some logcat at the beginning and at the end of the method body and you'll see where the error is.
EDIT: another thing, why did you put that if?
if (oldVersion < 2)
It's not necessary at all.

Android - Why am I getting NullPointerException in SQLiteOpenHelper onCreate?

I have used LogCat to determine the problem line.
The SQL String I am trying to execute in onCreate is..
CREATE TABLE Routines(_id integer primary key autoincrement, json TEXT);
When it tries to execute this, the problem occurs.
This may well be whats causing the NullPointerException. If you can't see anything wrong with that, please read on for a bit more background.
This database has not been created yet, I keep getting a NullpointerException, I have compared this to previous SQLite code and the problem is proving evasive.
However, I mention this as it still has to go through the onCreate method. I create a new DatabaseOpenHelper (extending SQliteOpenHelper) in my main code and call the helper's open() method as seen below.
public void open() throws SQLException
{
ssDatabase = databaseOpenHelper.getWritableDatabase();
}
If I am not mistaken, as my database has not been created (I made sure of that through uninstalling it prior). The onCreate SQLiteHelper is invoked when that open() method is called.
This is the code where I call that open method.
try
{
dbConnector = new DatabaseConnector (this);
debug = "2 ";
// This on first start will invoke the database onCreate method - throws SQLException
dbConnector.open(); /* PROBLEM LINE */
debug = "3 ";
}
catch (Exception e)
{
textView1.setText(debug + e.toString());
}
And this is the code containing my DatabaseOpenHelper and onCreate method
private class DatabaseOpenHelper extends SQLiteOpenHelper
{
public DatabaseOpenHelper(Context context, String name, CursorFactory factory, int version)
{
super(context, name, factory, version);
Log.i(TAG, "Constructor");
}
// On initial creation of database
#Override
public void onCreate(SQLiteDatabase db)
{
Log.i(TAG, "Before SQL command");
String sqlCreateCommand = "CREATE TABLE Routines"
+ "(_id integer primary key autoincrement, "
+ "json TEXT);";
Log.i(TAG, sqlCreateCommand);
// I believe this to be the PROBLEM LINE
ssDatabase.execSQL(sqlCreateCommand);
Log.i(TAG, "Jab done");
}
// On upgrade - currently do nothing
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{}
}
Thanks for the help!

seems like i dont have the prvilege to just post a comment. One question: ssDatabase.execSQL(sqlCreateCommand); --> shouldn't this be db.execSQL(sqlCreateCommand);
since the parameter is SQLiteDatabase db. Secondly you use _id. is this index not created by default ? Nevermind if this has nothing to do with it. This were just my thoghts about it. :)

How do I know when to update the database - Android

Hey
I'm building an Android app that contains a database.
My question is how can I know whether the app was updated?
I mean, I know the onUpgrade method is called when the DATABASE_VERSION from -
public DataBaseHelper(Context context) {
super(context, DB_NAME, null, DATABASE_VERSION);
this.myContext = context;
}
is lower than the version of the app, but how do I increment it after the update, so the app won't update itself all the time?

You don't need to take care of keeping track of the version number. After onUpgrade() has been called, android takes care of all this stuff automatically. onUpgrade() will automatically be called when the next update is due (i.e. you increased DATABASE_VERSION once again).
To be even more clear: Just keep a static final int DATABASE_VERSION field, which you increase at development time, everytime you change something essential on the database structure.
You create a class that extends SQLLiteOpenHelper which basically looks like this:
public class ContentDatabase extends SQLiteOpenHelper {
// Whenever you change the DB structure, increment DATABASE_VERSION (it starts from 1, so your first upgrade should be 2)
// - note it's only used for upgrades; if it's a new install, onUpgrade won't be called and everything is done by onCreate instead
private static final int DATABASE_VERSION = 6;
public ContentDatabase(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
public void onCreate(SQLiteDatabase db) {
// Code to create the most recent version of your database
// i.e. CREATE TABLE xxx (....)
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Code to update an existing database structure to the most recent
// version.
if (oldVersion < 2) {
// do something to upgrade the DB to version 2
}
if (oldVersion < 3) {
// do something to upgrade the DB to version 3
}
if (oldVersion < 6) {
// Let's assume you added a new table in v4, and then added a field to that new table in v6
if (oldVersion < 4) {
// add the v6 version of the new table to the DB
}
else {
// add the new field to the existing v4 table in the DB
}
}
}
}
Everytime you need to change the structure of the table (i.e. add aditional columns or tables) you increase the DATABASE_VERSION variable by one and write code accordingly for the onCreate() and onUpdate() methods. These methods are called automatically by android.

Consider using SharedPreferences in the application context, you can keep track of lastVersion in there and your application will check it onCreate() to see if lastVersion matches the version of this application.
It is persistent between updates but not between installs.
you can make it so version 0 equates to not having it which you require you to setup the new database. By using SharedPreference mPref = getSharedPreference(String,int)
You can then have code like
if(mPref.getInt("DB_VERSION", 0) == 0 ) {
no db yet so create one
} else { db is there,
if (mPref.getInt("DB_VERSION",0) != DATABASE_VERSION) {
do some special update stuff here
}
}