DbSync

Small library for sync android SqlLite database to cloud storage (for now only GDrive)

Motivation

There is not solution to sync SqLite database between device without the of custom server application or use of paid online cloud service. My solution it's base a json file on GDrive cloud account of user with no server involved, so all data are private to user e non saved on server.

How work

The library write a file on GDrive called cloud file like:

{
  "name" : "db2.db",
  "formatVersion" : 1,
  "schemaVersion" : 1,
  "tableCount" : 2,
  "tables" : [ {
    "name" : "name",
    "recordsCount" : 1,
    "records" : [ {
      "NAME" : "myname",
      "SEND_TIME" : 1487887189513,
      "CLOUD_ID" : "c2bd71ee-3f1b-4dca-b478-ebecaaa1f835"
    } ]
  }, {
    "name" : "category",
    "recordsCount" : 2,
    "records" : [ {
      "NAME" : "cat1",
      "SEND_TIME" : 1488038770858,
      "CLOUD_ID" : "6f2a8bcc-f1ee-4f14-8987-9f4275205793"
    }, {
      "NAME" : "musica",
      "SEND_TIME" : 1487887376113,
      "CLOUD_ID" : "52a292b5-8f38-4f30-b13f-7f86bbff49a6"
    } ]
  } ]
}

The library download the file from cloud storage and update the local database using the cloud id used to connect a record in 2 different device and and the send time use to understand is the record it's to update. The solution try to update only the record who are been update from last sync time, for performance reason don't update all database, after the sync process it generates the cloud id (uuid) and rewrite the json cloud file and upload to file storage.

Note: with GDrive you can share between more user

Your table need to have two columns for syn SEND_TIME long and CLOUD_ID TEXT unique

Features

The library support:

• Sync of 1 o more table
• Sync join table (updating the correct id)
• Support more match rule (default use CLOUD_ID counted with uiid faction)
• Support for ignore selected column
• Support for filter on what to sync (usefull for multi account application but different sync file)

Not supported yet

• Other cloud storage
• Support for images and file
• Delete elements (to solve use a state column or column whit deleted flag)

Usage

Simple example usage of library

1 Table

CloudProvider gDriveProvider = new GDriveCloudProvider.Builder(this.getBaseContext())
        .setSyncFileByDriveId(mDriveId)
        .setGoogleApiClient(mGoogleApiClient)
        .build();

DBSync  dbSync = new DBSync.Builder(this.getBaseContext())
        .setCloudProvider(gDriveProvider)
        .setSQLiteDatabase(mDB)
        .setDataBaseName("db1")
        .addTable(new TableToSync.Builder("name").build())
        .build();

2 Table

CloudProvider gDriveProvider = new GDriveCloudProvider.Builder(this.getBaseContext())
        .setSyncFileByDriveId(mDriveId)
        .setGoogleApiClient(mGoogleApiClient)
        .build();

DBSync dbSync = new DBSync.Builder(this.getBaseContext())
        .setCloudProvider(gDriveProvider)
        .setSQLiteDatabase(mDb)
        .setDataBaseName("db2")
        .addTable(new TableToSync.Builder("name").build())
        .addTable(new TableToSync.Builder("category").build())
        .build();

1 Table whit filter

CloudProvider gDriveProvider = new GDriveCloudProvider.Builder(this.getBaseContext())
        .setSyncFileByDriveId(mDriveId)
        .setGoogleApiClient(mGoogleApiClient)
        .build();

TableToSync tableName = new TableToSync.Builder("name")
        .setFilter("FILTER = 0") // send data with apply FILTER = 0 before send
        .build();

DBSync dbSync = new DBSync.Builder(this.getBaseContext())
        .setCloudProvider(gDriveProvider)
        .setSQLiteDatabase(mDB)
        .setDataBaseName("db3")
        .addTable(tableName)
        .build();

2 Table whit join

CloudProvider gDriveProvider = new GDriveCloudProvider.Builder(this.getBaseContext())
        .setSyncFileByDriveId(mDriveId)
        .setGoogleApiClient(mGoogleApiClient)
        .build();

// Keep the order
TableToSync tableCategory = new TableToSync.Builder("CATEGORY")
        .build();

TableToSync tableArticle = new TableToSync.Builder("ARTICLE")
        .addJoinTable(tableCategory, "CATEGORY_ID")
        .build();

DBSync dbSync = new DBSync.Builder(this.getBaseContext())
        .setCloudProvider(gDriveProvider)
        .setSQLiteDatabase(mDB)
        .setDataBaseName("db4")
        .addTable(tableCategory)
        .addTable(tableArticle)
        .build();

How sync

To start sync process

dbSync.sync();

How Insert/Update Data

Every time you insert or update a record simple set SEND_TIME to null

Installation

Add the dependencies to your gradle file:

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}
dependencies {
        compile 'com.github.claudiodegio:dbsync:X.Y.Z'
}

License

Copyright 2020 Claudio Degioanni

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.