Apply Maps/ IF Statements

[LB187]

I am pretty new to Qlik I am attempting to use Apply Maps and an IF Statement for the following issue:

I have 3 tables of data

(Fact) Table - Table A - churnID, Client ID, Indicator

(Lookup) Table B -churnID, Description ID, Description

Table C - Description ID, Description

Only Table A & B have the same churn ID(field) so the lookup is easy, however in table A there is an 'Indicator' field IF a '2' then I should lookup and return the Description field in Table C, IF the indicator is NULL then by default it should return the description in Table B?

Please help 🙂

[sidhiq91]

@LB187  Could you please provide Samples from all the 3 tables and also the expected output so that we could you help you to resolve this issue.

[marcus_sommer]

You need multiple and partly nested mappings, maybe something like this:

MapDescriptionB:
mapping load [Description ID], Description from B;

MapDescriptionC:
mapping load [Description ID], Description from C;

MapDescriptionID:
mapping load churnID, [Description ID] from B;

Final:
load *,
   if(Indicator = 'a',
       applymap('MapDescriptionC', applymap('MapDescriptionID', churnID, null()), 'no match C'),       
       applymap('MapDescriptionB', [Description ID], 'no match B')) as Description
from A;

- Marcus

[GnaneswarReddy]

Try this way , bit lengthy but will do the job for you

T3:
MAPPING Load * inline [
DescriptionID, Description
A1,AAA
A2,BBB
A3,CCC
A4,DDD
];

T2:
LOAD *,
ApplyMap('T3',[DescriptionID]) AS Description_C;
Load * inline [
churnID, DescriptionID, Description
1,A1,AAA
2,A2,BBB
3,A3,ABCE
4,A4,FFF
];

T1:
Load *,
If(len(Indicator) <> '0',
Lookup('Description_C',[churnID],[churnID],'T2'),
Lookup('Description',[churnID],[churnID],'T2')) as Description;
Load * inline [
churnID, Client ID, Indicator
1,1,1
2,2,2
3,3,
4,4,4
];

drop table T2;