--- a/doc/book/en/development/devcore/dbapi.rst Fri Apr 23 17:56:01 2010 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,119 +0,0 @@
-.. _dbapi:
-
-Python/RQL API
-~~~~~~~~~~~~~~
-
-The Python API developped to interface with RQL is inspired from the standard db-api,
-with a Connection object having the methods cursor, rollback and commit essentially.
-The most important method is the `execute` method of a cursor.
-
-.. sourcecode:: python
-
- execute(rqlstring, args=None, build_descr=True)
-
-:rqlstring: the RQL query to execute (unicode)
-:args: if the query contains substitutions, a dictionary containing the values to use
-
-The `Connection` object owns the methods `commit` and `rollback`. You
-*should never need to use them* during the development of the web
-interface based on the *CubicWeb* framework as it determines the end
-of the transaction depending on the query execution success. They are
-however useful in other contexts such as tests or custom controllers.
-
-.. note::
-
- While executing update queries (SET, INSERT, DELETE), if a query generates
- an error related to security, a rollback is automatically done on the current
- transaction.
-
-Executing RQL queries from a view or a hook
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-When you're within code of the web interface, the db-api like connexion is
-handled by the request object. You should not have to access it directly, but
-use the `execute` method directly available on the request, eg:
-
- rset = self._cw.execute(rqlstring, kwargs)
-
-Similarly, on the server side (eg in hooks), there is no db-api connexion (since
-you're directly inside the data-server), so you'll have to use the execute method
-of the session object.
-
-
-Important note about proper usage of .execute
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Let's say you want to get T which is in configuration C, this translates to:
-
-.. sourcecode:: python
-
- self._cw.execute('Any T WHERE T in_conf C, C eid %s' % entity.eid)
-
-But it must be written in a syntax that will benefit from the use
-of a cache on the RQL server side:
-
-.. sourcecode:: python
-
- self._cw.execute('Any T WHERE T in_conf C, C eid %(x)s', {'x': entity.eid})
-
-The syntax tree is built once for the "generic" RQL and can be re-used
-with a number of different eids. There rql IN operator is an exception
-to this rule.
-
-.. sourcecode:: python
-
- self._cw.execute('Any T WHERE T in_conf C, C name IN (%s)'
- % ','.join(['foo', 'bar']))
-
-Alternativelly, some of the common data related to an entity can be
-obtained from the `entity.related()` method (which is used under the
-hood by the orm when you use attribute access notation on an entity to
-get a relation. The initial request would then be translated to:
-
-.. sourcecode:: python
-
- entity.related('in_conf', 'object')
-
-Additionnaly this benefits from the fetch_attrs policy (see
-:ref:`FetchAttrs`) eventually defined on the class element, which says
-which attributes must be also loaded when the entity is loaded through
-the orm.
-
-
-.. _resultset:
-
-The `ResultSet` API
-~~~~~~~~~~~~~~~~~~~
-
-ResultSet instances are a very commonly manipulated object. They have
-a rich API as seen below, but we would like to highlight a bunch of
-methods that are quite useful in day-to-day practice:
-
-* `__str__()` (applied by `print`) gives a very useful overview of both
- the underlying RQL expression and the data inside; unavoidable for
- debugging purposes
-
-* `printable_rql()` produces back a well formed RQL expression as a
- string; it is very useful to build views
-
-* `entities()` returns a generator on all entities of the result set
-
-* `get_entity(row, col)` gets the entity at row, col coordinates; one
- of the most used result set method
-
-.. autoclass:: cubicweb.rset.ResultSet
- :members:
-
-
-The `Cursor` API
-~~~~~~~~~~~~~~~~
-
-The whole cursor API is developped below.
-
-.. note:
-
- In practice we use the `.execute` method on the _cw object of
- appobjects. Usage of other methods is quite rare.
-
-.. autoclass:: cubicweb.dbapi.Cursor
- :members: