topic ApplyMap in QlikView

ApplyMap

Anonymous — Wed, 22 Feb 2012 07:14:24 GMT

The following is directly from the HELP MENU of Qlikview:

// Assume the following mapping table:

map1:

mapping load * inline [

x, y

1, one

2, two

3, three ] ;

ApplyMap ( 'map1', 2 )	returns	' two'
ApplyMap ( 'map1', 4 )	returns	4
ApplyMap ( 'map1', 5, 'xxx' )	returns	'xxx'
ApplyMap ( 'map1', 1, 'xxx' )	returns	'one'
ApplyMap ( 'map1', 5, null( ) )	returns	NULL
ApplyMap ( 'map1', 3, null( ) )	returns	'three'

WHY does the following return as 'xxx', or why does not return as NULL?

ApplyMap ( 'map1', 5, 'xxx' )

returns

'xxx'

Why does each of the ApplyMap only return a single value, such as the following? Will it always return the first value it reads or recognizes?

ApplyMap ( 'map1', 1, 'xxx' )

returns

'one'

ApplyMap

CELAMBARASAN — Wed, 22 Feb 2012 07:21:31 GMT

Hi,

1.ApplyMap ( 'map1', 5, 'xxx' ) returns 'xxx' only because you don't have the value 5 in the map1 mapping table.if you wrote the expression as ApplyMap ( 'map1', 5) then it returns null.

2. Yes.It returns single value only.It look for the given value 1 in field x of the mapping table if matched then it returns the corresponding y field value.if not found it looks for the next parameter in applymap('map1',1,'xxx') (the bold one) which is optional.If you specified it returns the given value otherwise returns null.

Celambarasan

ApplyMap

Anonymous — Wed, 22 Feb 2012 07:28:46 GMT

'xxx' doesn't exist in the mapping table either, so why does it return instead of NULL?

Re: ApplyMap

CELAMBARASAN — Wed, 22 Feb 2012 07:31:04 GMT

Hi,

Third parameter is not to look up in mapping table its to display if there is no match then return this value instead of null.Its like default value.

Celambarasan

ApplyMap

Anonymous — Wed, 22 Feb 2012 07:44:03 GMT

Will the default value be specified previously in the script? If not, where does it come from? How does the program recognize it as the default value?

can the default value be a numerical value (eg 8), or is it always a text value (eg (xzy) (abc)?

ApplyMap

CELAMBARASAN — Wed, 22 Feb 2012 07:52:04 GMT

Hi,

I just told default value as example.

ApplyMap Syntax is

ApplyMap(MapptableName,value to look up in table[,value if not match])

You have to specify the value here in the optional parameter(Bold part) it returns the optional value if there is no match.If not specified then it consider as null value so it returns null if no match found.

Example:

ApplyMap ( 'map1', 5, 'xxx' ) returns 'xxx'

ApplyMap ( 'map1', 5) returns NULL

ApplyMap ( 'map1', 1, 'xxx' ) returns 'one'

ApplyMap ( 'map1', 1 ) also returns 'one'

ApplyMap

Anonymous — Wed, 22 Feb 2012 08:01:21 GMT

Got it, Thanks so much for your help