web2py/web2py — pull request #21 by dhx (2012-08-09 17:17:23+00:00)
Title: fixed problem with duplicate fields in insert of computed fields

The following code produces duplicate fields in the insert:
```python
db = DAL('sqlite://test.sqlite')
db.define_table('tree',Field('a',compute=lambda x: x.b),Field('b',compute=lambda x:x.a))
db.tree._insert(a=1,b=2)

"INSERT INTO tree(a,b,a,b) VALUES ('1','2','2','1');"
```

which does not produce an error in sqlite, but oracle does not like it...

The attached fix basically reverts the commit: a508e9f8ab3b8063d3337932f937a5bd10f90513
Unfortunately I don't know what problem this commit fixed...