[Vtigercrm-developers] RFC: schema versioning

[Enrico Weigelt]

Hi folks,


as some of you probably might have realized that upgrading 
database schema is an very tricky issue. 

I don't believe that an universal schema generator and updater, 
which really *WORKS* can be built with reasonable effort, at 
least not if the RDBMS should not just be abused as spreadsheet
storage. 

The various RDBMS'es *are* different and so require different
schemata. The big problem is not writing proper SQL commands,
but keeping track of current schema version and find the 
right commands for update.

So my suggestion:

* add an new table "schema_version" which contains an list 
  of schema components (identified by some unique name) 
  and their current version (which is an sequential number).

* schema updates are done, for each component separately, 
  strictly sequential. each RDBMS has its own SQL scripts.
  
  
cu
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