topic Re: How does QlikView perform Concatenation? in QlikView

How does QlikView perform Concatenation?

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

Hi all,

Please, I need somebody to explain how QlikView would concatenate Table B with Table A. The two tables are shown in the image below. Do note that the order of the columns are not exactly the same in both tables.

Besides, when we say:

CONCATENATE [Table XX]

LOAD …. ;

What is the order of operation - is it result of LOAD statement CONCATENATE [Table XX] or

[Table XX] CONCATENATE result of LOAD statement ?

What would be the name of the table resulting from the CONCATENATE operation?

Thanks you for your patience.

Re: How does QlikView perform Concatenation?

vamsee — Wed, 05 Sep 2018 17:41:58 GMT

Hi Jonathan,

Qlik concatenates (appends new rows) to the first table based on column names. Hence, they do not have to be in the same order of Table A.

Coming to your second question Result of Load statement of Table B is appended to TableA. (Test it with a where clause in TableB)

The result would be TableA itself.

Re: How does QlikView perform Concatenation?

Anonymous — Wed, 05 Sep 2018 21:35:31 GMT

Thanks for the response. So, what happens when some columns in table B do not have matching names in table A?

Re: How does QlikView perform Concatenation?

vishsaggi — Wed, 05 Sep 2018 21:40:00 GMT

If you use CONCATENATE final table will have this new Column with Nulls in TableA for this column and values for tableB. If you do not use CONCATENATE keyword synthetic keys will be formed.

Re: How does QlikView perform Concatenation?

vamsee — Wed, 05 Sep 2018 21:40:25 GMT

Blank records are created in Table A.

LOAD

Product

FROM TableA;

concatenate

LOAD

Customer,

Product

From TableB;

o/p:

Customer	Product	Source
	1	TableA
	2	TableA
	3	TableA
	4	TableA
123	5	TableB
234	6	TableB
345	7	TableB
456	8	TableB

Re: How does QlikView perform Concatenation?

Anonymous — Wed, 05 Sep 2018 21:57:06 GMT

Thank you all for these responses. I really appreciate them. The illustration makes it look easy. Nevertheless, I am just a beginner in QlikView. I am not sure whether the answers are correct or not. So, I leave it for those who are well grounded in QlikView to determine whether or not the answers are correct.

Re: How does QlikView perform Concatenation?

abednego — Thu, 06 Sep 2018 07:42:05 GMT

Hi Jonathan

The answers are correct. Please mark as answered.

Re: How does QlikView perform Concatenation?

vamsee — Thu, 06 Sep 2018 13:47:06 GMT

No problem Jonathan. Glad that we could help.

Furthermore, you would be able to find more details about concatenation on Qlik help.

https://help.qlik.com/en-US/qlikview/November2017/Subsystems/Client/Content/LoadData/concatenate-tables.htm

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Re: How does QlikView perform Concatenation?

Anonymous — Thu, 06 Sep 2018 15:03:27 GMT

Thank you once again.