topic What is the difference between Concatenate and join? in QlikView

What is the difference between Concatenate and join?

siva_boggarapu — Wed, 03 Aug 2011 10:23:57 GMT

Hi Everyone,

can any one describe me difference between concatenate and join.

What is the difference between Concatenate and join?

Miguel_Angel_Baeyens — Wed, 03 Aug 2011 10:58:19 GMT

Hi,

Please check the Reference Manual in your documentation folder for further documentation.

Basically, concatenating adds records (rows) regardless they structure and values to a previous loaded table, while JOIN adds fields (columns) to a previous loaded table.

You can find more info on the subject with examples in Barry Harmsen's blog. (among many others)

Hope that helps.

Miguel Angel Baeyens

BI Consultant

Comex Grupo Ibérica

What is the difference between Concatenate and join?

siva_boggarapu — Wed, 03 Aug 2011 11:19:17 GMT

Hello Miguel,

Thank you

What is the difference between Concatenate and join?

Wed, 03 Aug 2011 13:47:21 GMT

HI,

Re: What is the difference between Concatenate and join?

johnw — Wed, 03 Aug 2011 21:35:26 GMT

Sumit's comment is from an old post of mine on the subject. Here's the full post with examples::

Concatenate just appends the records from the new source onto the end of the existing table. There are many forms of join, but they all try to match up "key fields" between the two tables. In QlikView's case, they match on all fields of the same name. So let's take some examples. First, here's our basic script. The concatenate or join will go in the indicated spot:

Table:
LOAD * INLINE [
Customer, Sales
Andy, 123
Becky, 234
];
// either concatenate or a join here
LOAD * INLINE [
Customer, Country
Becky, Canada
Carla, Mexico
];

And here are the expected results for our various options. Hopefully I got all these right.

CONCATENATE (Table)

Customer, Sales, Country
Andy, 123, null
Becky, 234, null
Becky, null, Canada
Carla, null, Mexico

------------------------------

LEFT JOIN (Table)

Customer, Sales, Country
Andy, 123, null
Becky, 234, Canada

------------------------------

RIGHT JOIN (Table)

Customer, Sales, Country
Becky, 234, Canada
Carla, null, Mexico

------------------------------

OUTER JOIN (Table)

Customer, Sales, Country
Andy, 123, null
Becky, 234, Canada
Carla, null, Mexico

------------------------------

INNER JOIN (Table)

Customer, Sales, Country
Becky, 234, Canada

Re: What is the difference between Concatenate and join?

siva_boggarapu — Thu, 04 Aug 2011 06:07:04 GMT

Hello John,

Thanks a lot. Nice example really .