1 

     2 

     3 API Python/RQL

     4 ~~~~~~~~~~~~~~

     5 

     6 The Python API developped to interface with RQL is inspired from the standard db-api,

     7 with a Connection object having the methods cursor, rollback and commit essentially.

     8 The most important method is the `execute` method of a cursor :

     9 

    10 `execute(rqlstring, args=None, eid_key=None, build_descr=True)`

    11 

    12 :rqlstring: the RQL query to execute (unicode)

    13 :args: if the query contains substitutions, a dictionary containing the values to use

    14 :eid_key:

    15    an implementation detail of the RQL cache implies that if a substitution

    16    is used to introduce an eid *susceptible to raise the ambiguities in the query

    17    type resolution*, then we have to specify the corresponding key in the dictionary

    18    through this argument

    19 

    20 

    21 The `Connection` object owns the methods `commit` and `rollback`. You *should

    22 never need to use them* during the development of the web interface based on

    23 the `CubicWeb` framework as it determines the end of the transaction depending

    24 on the query execution success.

    25 

    26 .. note::

    27   While executing update queries (SET, INSERT, DELETE), if a query generates

    28   an error related to security, a rollback is automatically done on the current

    29   transaction.