Thanks for your replies
I chose SQLite because it seemed easy to setup ! I found several samples using it in the forum. In my personal case, nomber of users will be 2 (my wife and me) with 1 phone and 1 tablet each, plus sometimes my children...
Later, Hamied says : SQLite does not support concurrent accesses. This is surprising me.
Is SQLite really a bad choice ???
@Magma :
Now using websocket.. you want to make it, more web-app, with no need of client-app (desktop or android) ... need only html5 browser ? What is your scope ?
This is not really a web app but more a client-server. My scope : the phone (or tablet) are used to send B4A "commands" to the B4J server which pilots at the beginning the home cinema system (a Raspberry replaces 6 IR remote boxes). Then, I added a hard disk and the SQLite database for managing adresses of videos, mp3, photos.. and return them to the phones or tablets (but also to the central HomeCinema).
I want now to add controls of home systems which need to "recall" the user(s). For example : somebody is ringing at the door. I understood that WebSocket was appropriate for managing these non continuous dialogs.
To be honest, for the moment, there is only one user. So, i did not verify concurrent accesses.
@aeric
I think the purpose of this example is for beginner to understand the basic without needing knowledge of database.
It was also my feeling, but with a few lines, it makes the job ! my need is similar : to sort/filter/show titles/parameters of videos/MP3/Photos (there was a huge work before in order to "normalize" and attach these parameters to the files). The videos/MP3/photos files are NOT in the database (only the disk adress of the file)