topic Re: concatenate and queries in QlikView

concatenate and queries

Mon, 26 Jan 2026 18:19:17 GMT

I'm new in Qlick.

imagine 2 fact tables one of pharmacy and other of laboratory.If they are concatenated in a one fact table table.

How do I know the patients of drug x who have a laboratory test?.

In SQL this question would be answered with a query between the two tables with a join. The two tables have in common only the patient identifier.

Can I answer if I concatenate the two fact tables? or is necessary that they need to be seperated.

Thanks.

Re: concatenate and queries

Michiel_QV_Fan — Fri, 04 Sep 2015 13:37:29 GMT

Concatenation will force QlikView to combine the tables, regardless of the structure and content. Equal named columns will be added in each other and unknown columns are simply added.

Your patientid should have the same name and then the data wll be available per patientid.

So, probably, yes.

Re: concatenate and queries

malini_qlikview — Fri, 04 Sep 2015 14:00:15 GMT

Hi,

Concatenate is used when you need to merge two or more tables that have identical structures. In the example you have explained, other than patient identifier there is no other columns identical then it is better to keep the tables separate linked to patient identifier.

Re: concatenate and queries

mphekin12 — Fri, 04 Sep 2015 14:21:05 GMT

Check out this document. It will help you understand the differenct between the Join and Concatenate functions. I would like to give credit to the person who created it, but I don't remember where I got it.

Hope it helps!

Re: concatenate and queries

mphekin12 — Fri, 04 Sep 2015 14:22:42 GMT

Malini,

I don't believe your statment is correct. Here is a description of Concatenate from the help text:

A concatenation is in principle the same as the SQL UNION statement, but with two differences: first that Concatenate prefix can be used no matter if the tables have identical field names or not; and secondly that no removal of identical records are made.

Re: concatenate and queries

malini_qlikview — Fri, 04 Sep 2015 14:37:44 GMT

Hi,

Though you can force concatenate the tables, I meant to say Concatenate statement could be recommended where you need to merge two or more tables that have identical structures and pertaining to the situation.

Re: concatenate and queries

Sun, 06 Sep 2015 19:57:59 GMT

Thank you very much.

I expose an example,I think is better to can answer my question.

Suppose a Table of pharmacy

patient id drug date_pharmacy

1 A 20150101

1 B 20150203

2 A 20150210

2 A 20150705

2 C 20150812

3 A 20140312

4 B 20140123

other of laboratory

patient id test_type date_lab

1 3 20150109

1 7 20150206

3 3 20140320

if i concanate.

patient id drug date_pharmacy test_type date_lab

1 A 20150101

1 B 20150203

2 A 20150210

2 A 20150705

2 C 20150812

3 D 20140312

4 B 20140123

1 3 20150109

1 7 20150206

3 3 20140320

Can I answer, with this estructure, the patients of drug A , that they have a test type 3?

I have a lot of Fact tables with similar estructures. Can I have two or more link tables in Qlikview?.

Thank you very much.

Re: concatenate and queries

Mon, 07 Sep 2015 06:08:15 GMT

Hi,

I think it might help u,

Concatenation Operation in QlikView Application: Part 1