Different between Concatenate and Join in the QV Script

[#1]

Can anybody explain the different between Concatenate and Join in the QV script when loading from two QVDs

Thanks,

[#2]

Hi,

You can look at a Rob Wunderlich Post:

http://qlikviewnotes.blogspot.com/2009/11/understanding-join-and-concatenate.html

Regards,

Yigal.

[Anonymous]

Badr,

Very briefly:
The purpose of JOIN is to add columns to a table.  As a side effect, there could be additional rows.  To join properly, the tables must have at least one common field.
The purpose of CONCATENATE is to add rows to a table.  As a side effect, there could be additional columns.

Regards,
Michael

[#4]

Joining needs a common field where Concatenate works more like append.

Table: A                    Table B:                         Table C:

A   B    C                   A  D  E           Left Join:  A  B  C  D  E

1    0    0                    1  5   6                          1   0   0  5  6

1    0    1                    1  7   3                          1   0   1  5  6                     

0    1    0                                                        1   0   0   7 3 ... and so on

Concatenate would give you.       Table C:

                                                 A  B  C D  E

                                                 1   0  0  -   -

                                                 1   0  1  -   -

                                                 0   1  0  -   -

                                                 1   -   -  5   6

                                                 1   -   -  7   3

Hope that makes it more clearer.

[janardhan]

Hi ,

Concatenate allows duplicate values , but join doesnt.

[#6]

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