evaluate()

[#1]

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?

[senpradip007 · Accepted solution]

bal&conditin returns

10

1<0

1<0

1>0

Now Evaluate() returns

10 as 10

1<0 means false ie 0

1>0 means true ie -1

[juraj_misina]

Hello bmggeddam. It is exactly as senpradip007 says.

[#4]

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

[anbu1984]

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

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

[juraj_misina]

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.

[#7]

s,

If

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

"new bal"

[#8]

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

[juraj_misina]

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).

[#10]

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