This post is related to the previous post in http://drupal.org/node/900928.
Parden me if I do not sound like understanding Drupal DB or DB in general.
When an externa DB is migrated into Drupal, shouldn't the original DB schema be intact?
marcvangend said,
"Once you have created your Drupal installation and configured it (especially the content types) so it can hold all data you want to store, you can use the migrate module (http://drupal.org/project/migrate) to convert the existing data to nodes in your Drupal database. "
It sounds like converting data in multiple tables into one table (with each row with node id)? By doing so, don't we lose the original schema?
Assume that the existing schema involves multiple tables and the data are spread over those tables. Does it still make sense to "convert the existing data to nodes in Drupal database?" It would be easy if the original data is stored in one table, but it would not be so if the data is spread over multiple tables. How can you convert the data spread in mutiple tables to nodes without suffering the issue of data redundancy and integrity? Each node may have to contain lots of duplicate field values and any change/deletion in a field value would cause changes in other nodes that have the same field. (I see each of those nodes as a row in a table.)
Why not to simply transform an external database to internal Drupal database without even converting to nodes? Is there any benefit of keeping the data in internal Drupal database (without utlizing nodes)?
If my understanding is correct, then does the benefit (of utilizing nodes by migration the data into Drupal nodes) outweigh the overhead (of keeping the node values consistent)?
Or, am I missing something?
