topic Re: Looped data model in QlikView

Looped data model

SuwerenPL — Sat, 16 Nov 2024 17:55:16 GMT

Hello,

while preparing an application I came to a halt when my data model suddenly looped:

I read the instructions about creating the link table, however I still failed to create it. My model looped even more and finally completely disintegrated and became unusable instead of becoming fixed.

I have absolutely no idea how to correct it. All the fields are necessary and if the names of the fields are the same, then they mean the same thing exactly (just changing field names leads to loss of data).

Please help by providing step by step instruction which fields should be renamed and how exactly the link table should be created. On that basis I can learn and understand how to perform such a task in the future. I have trouble understanding the instructions containing expressions similar to "use your skill and judgement" as I never did this before and therefore posess no skill and basis for judgement in executing such an operation.

Regards

Re: Looped data model

dplr-rn — Mon, 26 Oct 2020 16:57:33 GMT

we cannot give eaxct steps without access to the data and knowing the business functionality.

but from a quick look at the picture.

the loop is due to tc_user-->MPK_kadry--> tc_tt_entries-->tc_user_log-->tc_user

you need disconnect either

tc_user-->MPK_kadry (comment column in MPK) or tc_user_log-->tc_user (comment user_id column in tc_user_log)

which one to comment is difficult to know without understanding your data.

hope that helps.

Also i would recommend denormalizing these towards a star schema. current data model is extremely inefficient. there are some good inexpensive courses in udemy

Re: Looped data model

Brett_Bleess — Wed, 04 Nov 2020 21:32:00 GMT

@SuwerenPL Have a look at the following Design Blog post, that should put you on the right track I believe:

https://community.qlik.com/t5/Qlik-Design-Blog/Circular-References/ba-p/1469332

Regards,
Brett

Re: Looped data model

SuwerenPL — Fri, 13 Nov 2020 13:09:28 GMT

@dplr-rn Commenting anything out was not an option, that would lead to the loss of data.

One of my coworkers suggested another solution that worked.

I mapped the fields from tc_user_log and moved them to tc_tt_entries. Mapping was done using Activity_key.

The model looks now like on the screen and behaves much better 🙂