I am integrating with a legacy database running MSSQL. The table names are
in camel case, so the global settings table is called GlobalSettings. Here
is the table definition as I have it:
db.define_table('GlobalSettings',
Field('SettingName', length=255),
Field('SettingValue', length=255),
Field('Setting_PKey', 'id'),
migrate=False
)
Doing a select on this table would look like this:
db().select(db.GlobalSettings.ALL)
I plan to eventually rename the tables and fields once my web2py application
takes over the current C# version of the project. My question is, would it
be possible to add an argument to define_table() and Field() that would
allow you to give a different name to the tables and fields for use in later
code? Maybe like an alias= attribute or something?
With something like that, I could apply the alias argument to each table and
field definition, then when I'm ready to rename the tables and fields in the
database, all I have to do is change the names in the db.py file. Otherwise,
I would have to change every line that uses the db object. Using an alias
argument would allow me to call and refer to the table or field by whatever
name I want. So my table definition would look like this:
db.define_table('GlobalSettings',
Field('SettingName', length=255, alias='name'),
Field('SettingValue', length=255, alias='value'),
Field('Setting_PKey', 'id', alias='id'),
migrate=False,
alias='global_settings'
)
Then a select would look like this:
db().select(db.global_settings.ALL)
And when I change the name of the table and fields in the database, my table
definition would be changed to look like this:
db.define_table('global_settings',
Field('name', length=255),
Field('value', length=255)
)
No changes to any other code would be necessary, as I would already be using
db.global_settings.name to refer to the GlobalSettings.SettingName field.
You will notice that in the last table definition above, I have removed
migrate=False, as the table can now be controlled using web2py's built in
migration functions.
I don't know how difficult a task it would be to add this functionality, but
it could go a long way into allowing web2py to integrate with legacy
databases, and optionally take over completely from the legacy application
using the legacy database.
