When to use concatenated load and join load?

[#1]

Hi All,

When to use concatenated load and join load?

Regards,

Attitude

[SunilChauhan]

if you want to append data into one table then use concatenate

if want to append data on basis of some key field use join

[#3]

Hi,

Concatenation and Join are there for two totally different purpose.

Concatenation is primarily used where we are getting same set of data from two different sources. for example one part of your data is coming from 1 table and another part of your data is coming from another table. So, you concatenate second table to 1st table and make 1 table from these 2 tables. It primary function is to add rows.

Join is primarily used when based on any key you want to add more fields to your table.for example you have a key field in your table and to get description you join description table to your 1st table to get description in 1st table.

The difference needs to be understood here is that concatenation does not do any search and just append the rows. while join will work on the base of search, it will search for the matching key values.

for example we have 2 tables

F1	F2
11	12
12	13
13	14

AND

F1	F2	F3
11	12	13
12	13	14
25	25	56

If we use concatenation then resulting table will be

F1	F2	F3
11	12
12	13
13	14
11	12	13
12	13	14
25	25	56

But if we do a join (suppose a full outer join) it will be like this.

F1	F2	F3
11	12	13
12	13	14
13	14
25	25	56

other joins in qlikview are inner join, left join, right join.

So, as you see both of them are having a different result and are used in different scenrios.