I am wondering to what extend OData is supported by Qlik. I can't try it out because apparently I need a customer or partner account to download the Qlik Web Connector. Is there any possibility to get a trial for this web connector? I have the following questions about the OData connector:
To what extent does Qlik make use of the OData service? Does it recognize relationships defined in the metadata document of the service? Does it push down filters defined by users to the service (by calling the service URL with $select, $expand, $filter etc..)?
As OData is a Premium connector you will need to get a trial licence to be able to give this a go. You should look to find a local Qlik Partner who should be able to provide this for you. If you are in the UK please get in touch.
Thanks for your reply Steve. Do you know if the web connector only supports OData v3? If so applying for a trial license would be kind of pointless. Otherwise I'll start looking into getting a trial license.
Little update on this, I've since gotten my hands on a license for the OData connector. It is possible to connect to OData v4 sources but it looks like the connector only accepts XML return values.
System query options can be used in the connector but sub queries seem to be ignored (for example $expand=something($select=Name)). And using the $expand options returns a table which adds the expanded entities as new rows, see here: Working with OData relational data. I'm not sure why this happens but it makes working with the data a hassle.
I've not yet encountered an API that doesn't have quirks.
When working with REST sources different hierarchical levels of data are all returned in a single table, with columns returning null when the row is not at the level that column is for. You need to pull the whole grouped table into a temporary table in Qlik and then do a number of resident loads, where a column in each hierarchy is non-null, to split into the constituent tables.
It sounds as if the OData connector may be doing something similar?
Glad you got a trial licence and can connect. Hope you can make it work for what you require it to do.