.. _Getting Data:

Getting Data

------------

You might have spotted this in the explanations about the views, to

get data, when not using a toplevel method, you will execute an RQL

`RQL chapter`

Basic cases

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In a similiar way that you might be used to in SQL, to obtain data

from the RQL backend, you will execute an RQL command and obtain a

resultset ::

Then, you can use the data from the rset.

XXX complete section with examples

Use of the cache for RQL execution

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Let's say you want to get T which is in configuration C, this translates to ::

But it can also be written in a syntax that will benefit from the use

of a cache on the RQL server side. ::

The syntax tree is build once for the "generic" RQL and can be re-used

with a number of different eid. Alternativelly, some of the common

data related to an entity can be obtained from the top-level

`entity.related()` method. The above would then be translated to ::

    entity.related('in_conf', 'object')

The `related()` method makes extensive use of the cache mechanisms so

you don't have to worry about them. Additionnaly this use will get you

commonly used attributes that you will be able to use in your view

generation without having to ask the data backend.