topic Re: PEEK() Related Query ??? in QlikView

PEEK() Related Query ???

Wed, 18 Mar 2015 09:32:22 GMT

Hi All,

I am new to Qlikview.I am trying to analyse Peek() functionality ,but i am unable to understand the exact functionality of this.It will be better if someone helps me to understand by giving some example.

what are the difference outputs we get by using the following :

Peek('Fieldname',1)

peek('Fieldname',2)

...................................

peek('Fieldname',-1)

peek('Fieldname',-2)

......................................

Re: PEEK() Related Query ???

jyothish8807 — Wed, 18 Mar 2015 10:49:10 GMT

Peek() is used in the script, pick() - on the front end. From Help:

peek(fieldname [ , row [ , tablename ] ] )

Returns the contents of the fieldname in the record specified by row in the internal table tablename. Data are fetched from the associative QlikView database.

Fieldname must be given as a string (e.g. a quoted literal).

Row must be an integer. 0 denotes the first record, 1 the second and so on. Negative numbers indicate order from the end of the table. -1 denotes the last record read.

If no row is stated, -1 is assumed.

Tablename is a table label, see Table Labels, without the ending colon. If no tablename is stated, the current table is assumed. If used outside the load statement or referring to another table, the tablename must be included.

Examples:

peek( 'Sales' )
returns the value of Sales in the previous record read ( equivalent to previous(Sales) ).

peek( 'Sales', 2 )
returns the value of Sales from the third record read from the current internal table.

peek( 'Sales', -2 )
returns the value of Sales from the second last record read into the current internal table.

peek( 'Sales', 0, 'Tab1' )
returns the value of Sales from the first record read into the input table labeled Tab1.

Load A, B, numsum( B, peek( 'Bsum' ) ) as Bsum...;
creates an accumulation of B in Bsum.

pick(n, expr1[ , expr2,...exprN])

Returns the n:th expression in the list. n is an integer between 1 and N.

Example:

pick( N'A''B'4, , , )

returns 'B' if N = 2

returns 4 if N = 3

Regards

Re: PEEK() Related Query ???

prma7799 — Wed, 18 Mar 2015 10:49:23 GMT

And peek function is only use in script part we cant use it on front-end.

Re: PEEK() Related Query ???

jyothish8807 — Wed, 18 Mar 2015 10:51:19 GMT

http://community.qlik.com/docs/DOC-4073

will be helpful

Regards

Re: PEEK() Related Query ???

Wed, 18 Mar 2015 10:54:15 GMT

Thank you Kc

Re: PEEK() Related Query ???

hariprasadqv — Wed, 18 Mar 2015 10:55:21 GMT

Hi Abhilash,

Peek() is very usefull in several scenarios where we need to selct top or bottom value in a field of the table.

Syntax:

Peek('Field_Name',position,'Table_name');

Here position will be represented with two values 0/-1.

Position 0=Return first Position values of that field in the specified table.

Position -1=Return Last position values of that field in the specified table.

Ex:

Table1:

SNO COUNTRY

1 India

2 US

3 UK

Peek('COUNTRY',0,'Table1') will return India.

Peek('COUNTRY',-1,'Table1') will return UK.

Re: PEEK() Related Query ???

jyothish8807 — Wed, 18 Mar 2015 10:56:17 GMT

Your welcome Abhilash

Regards

Re: PEEK() Related Query ???

ravindraa — Wed, 18 Mar 2015 11:01:37 GMT

Hi Abhilash,

peek functon return the values from coresponding field based on the specified intiger value wise.

syntax : peek('FieldName',interger,'TableName')

ifwe mention Integer as 0 - it returns first record

if we mention interger as 1 - it returns second record

ifwe mention interger value as -1 - it returns last first record.

Regards

Ravindra