topic Re: Require basic data model creation tips - urgently required in QlikView

Require basic data model creation tips - urgently required

Anonymous — Wed, 25 Nov 2020 16:16:04 GMT

Is it fine if my data model is created with natural joins. Basically multiple tables will be pulled from different data sources. If existing connections in these tables are used as in the existing data source is it fine to go ahead with the data model. I will not be creating a star or snowflake just use the existing connections. Is it fine to go ahead with this kind of a data model.

Re: Require basic data model creation tips - urgently required

Peter_Cammaert — Mon, 06 Nov 2017 15:22:16 GMT

A few remarks regarding what I think you are trying to tell us:

Usually there aren't any connections at all between different data sources, so they will not deliver any when you extract the data. You'll have to explicitly specify how the different data sources relate to each other. This may imply performing a good deal of transformations.
In an RDBMS, connections are usually supplied by the queries your applications perform on the tables (and by the defintions of constraints and foreign keys). Extracting the data from an RDBMS doesn't include any of this connection information.
QlikView connects fields and tables to one another by way of columns having the same name. But QlikView doesn't bother with the actual content of these columns, so the data may not match at all. You'll have to make sure that identically named columns actually contain the same type of data.
Moreover, QlikView doesn't like the connection of two tables by way of multiple keys. Natural Joins à la QlikView have the habit of using multiple key fields, circular references and possibly a large amount of synthetic keys. All of them should be eliminated or replaced by something better.

When creating a QlikView data model, the existing data source architecture and query logic can be a big help for the design of an initial QlikView data model and the required associations. But there is only a small chance that you can import an existing data model as-is into QlikView and make it work without a change.

Re: Require basic data model creation tips - urgently required

Anonymous — Tue, 07 Nov 2017 01:40:10 GMT

Hi Peter,

Can you please share an example of how to create a data model in qlikview. Please attach a sample file. Something simple to start with. That will be of great help.

Thanks in advance.

Re: Require basic data model creation tips - urgently required

Peter_Cammaert — Tue, 07 Nov 2017 10:45:55 GMT

See here: Creating a Data Model (all required files are included)

This document is part of a very nice series for the beginning QlikView developer: New to QlikView Videos