topic Re: Conditional concatenation in QlikView

Conditional concatenation

bharath28 — Tue, 03 Nov 2015 11:45:50 GMT

Hi All,

I want to concatenate the 2nd table to 1st table, only when 1st table is already loaded, otherwise don't concatenate.

Script-->

IF vFlag = 1 then

Table1:

load...;

ENDIF

If NoOfRows('Table1') > 0

Set vConcatenate = CONCATENATE(Table1);

ELSE

Set vConcatenate = ;

ENDIF

$(vConcatenate)

Table2:

load...;

The issue is the dollar expansion $(vConcatenate) is enabling red lines in the below load script. How to avoid this and write a clean code.

Re: Conditional concatenation

Anonymous — Tue, 03 Nov 2015 11:49:04 GMT

That is a cosmetic bug in the syntax checker, so you will just have to live with it.

Re: Conditional concatenation

sunny_talwar — Tue, 03 Nov 2015 11:50:54 GMT

I don't think there is a way to avoid those red lines when you are using a variable. May be you can do something like this:

IF vFlag = 1 then

Table1:

load...;

Concatenate(Table1)

load...;

ELSE

Table2:

load....;

ENDIF

Re: Conditional concatenation

Kushal_Chawda — Tue, 03 Nov 2015 11:51:13 GMT

try

IF vFlag = 1 then

Table1:

load..

From Table1;

ENDIF

IF NoOfRows('Table1') > 0 then

concatenate(Table1)

load...

From Table2;

ENDIF

Re: Conditional concatenation

santiago_respane — Tue, 03 Nov 2015 12:11:59 GMT

Hi Bharath,

the only time i had to do that it wasnt a complex loading load sentence so i solved it with no variables, the bad thing about it is that the load sentence must be added twice and its not a good practice.

Hope it helps!

Kidenst regards,

LOAD * INLINE [
Col1,Col2
345,dfg
456,fgh ];
If (NoOfRows('Table1') > 0) THEN
     CONCATENATE(Table1)
     Table2:
      LOAD * INLINE [
      Col1,Col2
      123,asd
      234,sdf ];
ELSE
      NOCONCATENATE
      Table2:
      LOAD * INLINE [
      Col1,Col2
      654,eqweq ];
ENDIF

Re: Conditional concatenation

Peter_Cammaert — Tue, 03 Nov 2015 12:29:11 GMT

If you use the code as shown in your OP, you will get run-time errors as well; the CONCATENATE (...) keyword should go after the table name, not before.

Or you can omit the Table2: label before the last LOAD and change the IF-THEN-ENDIF into:

If NoOfRows('Table1') > 0

Set vConcatenate = CONCATENATE(Table1);

ELSE

Set vConcatenate = Table2:;

ENDIF

Re: Conditional concatenation

sunny_talwar — Tue, 03 Nov 2015 12:40:47 GMT

Peter I think I have seen Join/concatenate/keep to work before the table name as well. So something like this is what I have seen before:

Join(TableName)

Table1

LOAD ....

Concatenate(TableName)

Table2

LOAD ....

Re: Conditional concatenation

bharath28 — Tue, 03 Nov 2015 14:14:56 GMT

@Sunny, you are right. The concatenate keyword works either above or below the table name.

Re: Conditional concatenation

bharath28 — Tue, 03 Nov 2015 14:20:09 GMT

Thanks Peter. Your solution is nice, however the syntax red lines seems cannot be avoided.