topic Re: difference between joins and applymap in QlikView

difference between joins and applymap

Anonymous — Wed, 05 Nov 2014 11:31:38 GMT

hi all,

what is the difference between join and applymap ?

Re: difference between joins and applymap

sushil353 — Wed, 05 Nov 2014 11:33:57 GMT

both serve the similar purpose..

In applymap.. you can replace a matching value in one field only..

but in case of join based on machining condition you can add multiple fields..

for more descriptive difference better to use QlikView help or reference manual.

HTH

Sushil

Re: difference between joins and applymap

robert99 — Wed, 05 Nov 2014 11:37:20 GMT

Read this

http://community.qlik.com/blogs/qlikviewdesignblog/2012/09/18/one-favorite-function-applymap

Re: difference between joins and applymap

its_anandrjs — Wed, 05 Nov 2014 11:37:40 GMT

Hi,

1.First and main difference when ever apply map is used then in map table we have maximum two fields required.

2.But in join this condition not apply, in the join when two table is used more than fields in a table can join but in one of the table unique keys is required for perfect join.

Regards

Anand

Re: difference between joins and applymap

robert99 — Wed, 05 Nov 2014 11:43:05 GMT

The reason I have used applymap a lot is (as opposed to join)

It only picks up the first record. (although not exists can be used to eliminate multi records but I feel its safer using applymap when a second entry for one record must be ignored)
Missing records can be given a name. Like 'Missing' . Or can be used to group records. So an excel spreadsheet will have the Focus Customers and the rest will be grouped as 'Other

The disadvantage are

applymap can only loookup one record. Say the Customer name for the Cust Number but not also the Cust Telephone number. Unless another apply map is used
Its more work to set up. Join is simple

Re: difference between joins and applymap

Anonymous — Wed, 05 Nov 2014 11:56:57 GMT

thank you

Re: difference between joins and applymap

Wed, 05 Nov 2014 12:15:58 GMT

Hi,

We can use Joins to combine/concatenate multiple records, there won't be any condition.

but in apply map the mapping table should contain only two fields and we can combine only one field. another field should be common field.