WM22/WD22 Database differs (HModifyStructure)

Startbeitrag von Rik am 24.08.2017 10:22

Hello all,

At the moment I am struggling with database modification.
My mobile app uses some database files which are used by a windev desktop application (HFSQL server).

If the Desktop updates the application, his database is modified accordingly.
Therefore differences between the description of the files between platforms occur.
The mobile application will not function anymore, the same happens if the mobile application updates before the desktop.

The mobile application is a read only slave. Is it possible to change its analysis, or atleast the logical files, according to the database it is connected to. Using for example a HModifyStructure?

This poorly drawn example should give more insight:



Hi Rik,

if all your clients are connecting DIRECTLY to your DB, then all your clients must be updated at the same time.

Which is one of the reason why I never connect my mobile clients directly to the DB. Instead, use a webservice or even better use a replicated DB.

With a webservice, you can obfuscate the changes in your DB structure (man in the middle) if you code it correctly, but your mobile app will still work only when it is connected to a good enough network.

With a replicated DB like WXreplication, you get both the obfuscation of remote changes AND the app still works when it looses connectivity. WXreplication uses a webservice for the transport, so you have all you need as a an example there if you want.

Best regards

von Fabrice Harari - am 24.08.2017 10:48
Hi Fabrice,

Thank you for your fast response. A shame that there is no fast solution.
For now it would take too much time to implement this kind of system.

In the future I will take a look at WXReplication!


von Rik - am 24.08.2017 13:21
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