Cross-Language SQLite access at the file level?

General
1

Suppose that I have a SQLite database file created using XOJO. Can that same file be accessed or maybe even modified from a python program? I would take care, of course, that the file is open by one server at a time; at the moment I am not sure how to assure that but the first question is whether or not it can be done!

Many thanks
Jim Wagner, Oregon Research Electronics

2

It can be done by a python program running on the same machine. SQLite files are not meant to be accessed across the network.

3

Thanks, Tim -

I was thinking of same machine or maybe (big maybe) duplicate files propagated by DropBox.

Here is the situation. I use KiCad, which is a circuit board layout “IDE”. It maintains a component data base which can be accessed via python helper apps. The code for those helper apps IS available so all of the necessary hooks seem to be laid out. I would like to write a helper app that copies particular data from the KiCad database to a more elaborate inventory management database that I am creating in XOJO. Now, there is an alternative route of having KiCad output its component information as a comma-separated-value text file, then parsing that file using XOJO into my own data base. I suspect the CSV route may be the more desirable since it is less sensitive to KiCad version changes. However, simply knowing that I have two possible routes reduces the stress level a lot.

Again, thanks Jim

4

AFAIK this is no longer true since 2010: Write-Ahead Logging

  1. WAL provides more concurrency as readers do not block writers and a writer does not block readers. Reading and writing can proceed concurrently.

And sure, this also works across the whole Network.

5

From your link

  1. All processes using a database must be on the same host computer; WAL does not work over a network filesystem

If you have used it “succesfully” over a network, you’ve just been lucky.

2 Likes
6

Dang! :slight_smile: Thanks, I actually got lucky then. But I only use something like this on a private NAS and in the local network.

7

That won’t help. This comes up regulalry on the SQLite Users Forum. SQLite uses file locks for concurrency, and Network File Systems are bad at this, see:

https://www.sqlite.org/howtocorrupt.html

8

Thank you. I’ve already started to replace it with a MariaDB10 mySQL-Database. :+1: