I want to two-way sync my Android app's sqlite database to a web app backed by a MySQL database. The web app is RESTful. Now I see two possible ways:
1. Sync directly to MySQL database
This seems easiest, but it seems like the storage mechanism of the web service should be abstracted from the synching. Also it feels like a potential security leak, as the MySQL server will need to listen globally instead of on just one IP (that of the web server). Just a gut feeling...
2. Sync indirectly using web service's API
I could also sync indirectly by PUTing/POSTing/DELETEing to the web service's URIs. This would nicely abstract the data storage mechanism from the sync and the database server would only need to listen on the web server's IP address.
But I wouldn't be able to use transactions anymore when synching (the db schema has bunch of foreign key relationships), and I can't see any way to deal with failed inserts from primary key collisions this way.
So both have advantages and drawbacks. Which is the way to go? How do professional products do this? Or is there another way that I haven't thought of?
Any thoughts would be greatly appreciated :)
Related
I have a project in vb.net and another in android studio I want to link them with one database (real time connection) what is the best way to do that (sql server-my sql ....other?)
Sql server is pretty easy to link to vb.net. you simply create a connection string with the server name and password, although I am not sure about android, but the process would probably be similar
It looks like you want to communicate between the two applications via SQL server, is that correct? While it is possible to do this it is highly ill-advised as the communication cannot be realtime (you would have to poll a table by selecting from it every ## seconds or use triggers MSSQL / MySQL in a very strange way) and it is likely to be unnecessary.
My suggestion is to consider what data you need to go back and forth and why. It is unusual for an Android app to directly connect to a database across the Internet because of the security risks in exposing a database publicly. Most developers opt to use a web application of some kind that provides an API for the Android app to consume. This prevents direct access to the database and provides you a place to add in all your business/game/other logic.
I have been looking and searching for this whole day, so i want to create a database which can be accessed by both computer and smartphone, is there a way to do it, and how ?
Sorry For Beginner Question, Thanks in Advance
Ok, the first thing you should do is to define the type of database
that you want. You can build SQL or No-SQL database. For the most
part I would suggest no-sql so something like MongoDB could do, but you can always do mySQL. As
for accessing that db with anything actually, you need application
layer around it. You see, database acts as just a huge data
container thus it should not be used for any other logic.
Now, lets talk about application layer. To be more precise - about posting/updating/retrieving data from db. You should research something about RESTApi or GraphQL concepts as they are used to make communication between your app and your db which is hosted on a server (I deliberately did not talk about how you can build an app because I assumed you already know this one).
THE POINT: The most important concept to wrap your head around is how you can access the db you make not the type or tech used to build it. (Even though this is important too)
Good luck!
The better way to do this its creating a web service, so your app will talk to this web service, the web service will talk to your database and retrieve the results to your app (this can be done using HTTP protocol's APIs like Volley for android) and its a secure way to do it.
You can connect your application direct to your database granting external access, but this is a specif configuration according to your database (mysql, ms sql, etc.) and its not recommended.
You can think in the same way to the computer(s) that will access your database, except if this computer(s) is in the same network which the computer that your database is hosted in, in this last case, the program in this computer (which will access the database) can access it directly (you need to setup the database to permit this and this setting is diferent according to your database).
I am developing an android application. I want to update the local SQLite database with MySQL database on server. I am not able to figure out that what is the most appropriate and standardized way to do so?
Create a webservice (REST is probably best) and serialize your SQLite/MySQL data and PUT/POST/GET it to/from your web service. This will give you a nice layer of abstraction in case you decide to switch from MySQL to something else server side.
You may want to take a look at fyrecloud.com/amsler This is source code for a demonstration Android application that implements MySQL replication between a MySQL server and the SQLite db on an Android device.
Amsler rests on two pillars:
It communicates with the MySQL server using the MySQL Client/Server protocol in order to connect to the server for authentication and for receiving replication events as they occur.
It uses the Antlr lex and parse software in order to lex and parse incoming replication events and then to translate the MySQL commands into equivalent SQLite commands.
This is great for one-way replication. You can simulate two-way replication by modifying the MySQL server indirectly via RESTful type methods and then watching while MySQL sends a new replication event back.
Accessing a server via REST is easy enough. However, modifying an existing MySQL installation in order to support serialization presents too many headaches to enumerate here. Amsler takes advantage of pre-existing replication services. REST also depends upon some polling strategy in order to keep the local device reasonably up-to-date. Again, many problems with this approach. Amsler maintains a TCP/IP connection to the server which enables server-push notification of updates.
The most difficult part of Amsler is in figuring out the lexing/parsing. The Syntax between MySQL, SQLite, and the various versions of the same have many subtle differences. So many differences that it's impractical to provide a shrink-wrap translator and instead you must resort to modifying the grammar yourself.
Nevertheless, good, bad, or ugly, here it is. Take a look and maybe the glove fits.
This is probably going to be helpful: sync databases Mysql SQLite
The real answer is that there is no standard or built in magic way to just copy a MySQL database that lives on a server somewhere to a device. You will have to implement either a webservice or somehow convert the MySQL db on the server to the android sqlite implementation and download that file into your app's data directory (not a route I'd recommend taking).
Late to the party, but http://www.symmetricds.org/ is a good solution.
Java, runs on Android too.
LGPL.
Can handle 10,000's of clients.
There is no standard way. Depending on your needs you can e.g. use webservices in REST or SOAP protocols or more binary data exchange.
i was trying to build an app which takes the data from server database and use it in android app ( in may case for reading the gprs coordinates available on database).
after a lot of search, i came across RESTfull services for implementing this. but there is a simpler way also, that is accessing the server database directly from android app by using a driver (jtds) and running mysql on server side.
i am actually confused which one to use. Why restful service which is highly platform independent and have a wide range or directly accessing the mysql database from server. which is most extensively used and why? giving below examples of both scenarios.
through restful service - http://avilyne.com/?p=105 and directly by accessing sql server database- http://amitku.wordpress.com/2011/08/03/how-to-connect-and-access-sql-database-server-from-android-app/
please let me know which is better and mostly used and why?
I would strongly encourage using the REST approach, and although there are many reasons, two or three come immediately to mind:
1.) Security. By using a REST approach, any data on the server side can only be accessed by server-side code, which can provide a protective layer between the data and the outside world.
2.) Scalability. A direct connection, such as the example at your link, hooks into a particular instance of a database. If that database already has a large number of connections, there will be performance issues or worse.
3.) Server side flexibility. If the underlying database structure or technology needs to change, a REST approach will allow for that. All the client side cares about is posting or requesting to a server that will respond via REST protocol.
I would think that a REST approach is much more widely used than a direct client-server approach.
I've done a lot of search about this but I don't found anything really useful.
I just want to know if it is possible to sync a remote database with an android sqlite database using SyncAdapter and content providers.
I don't want to use another solution like webservices or sending the database file to server, and if possible I need to implement rules to resolve conflicts.
Thanks.
You'll still have to use something like web services to wire them together, there is no automatic mechanism to do that like sql replication or anything. All the SyncAdapter provides is a system managed periodically run service that's intended to be used for syncing data. You have to write all the code to talk to the local database and the remote database and manage moving the data between them.