topic Re: evaluate() in QlikView

evaluate()

Fri, 20 Feb 2015 04:05:41 GMT

juraj.misina lets say data is like:

tab1:

load * inline [
bal,conditin,coef
1,0,1
1,<0,2
1,<0,3
1,>0,4
];
tab2:
load
If(conditin=0,(bal*coef),if(Evaluate(bal&conditin),(bal*coef),0)) as "new bal" Resident tab1;

please tell me here what exactly Evaluate(bal&conditin) is doing?

Re: evaluate()

senpradip007 — Fri, 20 Feb 2015 04:36:33 GMT

bal&conditin returns

1<0

1>0

Now Evaluate() returns

10 as 10

1<0 means false ie 0

1>0 means true ie -1

Re: evaluate()

juraj_misina — Fri, 20 Feb 2015 07:11:50 GMT

Hello bmggeddam. It is exactly as senpradip007 says.

Re: evaluate()

Fri, 20 Feb 2015 09:54:59 GMT

when i put fields in chart, the o/p is as follows can u tell me y it happens?@Pradip Sen

bal	coef	conditin	new bal
1	1	0	0
1	1	0	1
1	1	0	4
1	2	<0	0
1	2	<0	1
1	2	<0	4
1	3	<0	0
1	3	<0	1
1	3	<0	4
1	4	>0	0
1	4	>0	1
1	4	>0	4

Re: evaluate()

anbu1984 — Fri, 20 Feb 2015 10:03:47 GMT

Did you use the same expr for "New bal" as in your post?

I am getting different "New bal" compared to above result

Re: evaluate()

juraj_misina — Fri, 20 Feb 2015 10:05:56 GMT

Seems like cartesian product, check table viewer if your tables are connected (have a common key field).

If you used the exact script from your first post, then adjust the second load to:

tab2:
load

coef,
If(conditin=0,(bal*coef),if(Evaluate(bal&conditin),(bal*coef),0)) as "new bal" Resident tab1;

To create a connection between the tables.

Re: evaluate()

Sun, 22 Feb 2015 04:47:02 GMT

(conditin=0,(bal*coef),if(Evaluate(bal&conditin),(bal*coef),0)) as

"new bal"

Re: evaluate()

Sun, 22 Feb 2015 04:49:14 GMT

s there was no connection juraj, but can u elaborate y it takes cartesian product

Re: evaluate()

juraj_misina — Mon, 23 Feb 2015 07:59:09 GMT

This is how QlikView behaves when you put fields from disconnected tables into a tablebox. QV cannot determine a link (because it does not exist), so it shows all possible combinations.

Be careful with this, it can have serious impact on performance (although disconnected tables - data islands - can be useful if properly used).

Re: evaluate()

Mon, 23 Feb 2015 09:02:28 GMT

s juraj, i am asking by taking wat fields in to account; cartesian product is applied at every iteration?