topic Re: Previous() and Peek() in QlikView

Previous() and Peek()

Tue, 18 Dec 2012 14:53:58 GMT

Difference between Previous() and Peek()

Please any one can give me Examples.......

Re: Previous() and Peek()

nagarajupinnibo — Thu, 21 Feb 2013 08:33:44 GMT

can anyone explain with example of peek() and previous() functions???

Re: Previous() and Peek()

Thu, 21 Feb 2013 08:52:21 GMT

previous used to pull previous record

where as peek is used to pull both first and last record

see http://qlikshare.com/tag/peek

Example of Previous() & Peek()--

inputtable:

LOAD *,Previous(sales) as previous

INLINE [

sales

123

153

1456

235

845

365

896

486

];

outputtable:

LOAD sales,

Peek(sales,3,'inputtable') as peek

Resident inputtable;

peek

235

previous
123
153
235
365
845
896
1456

********************************************************************

Below()--

Returns values as they appear on the row below the current row within a column ,

On the last row of a column segment a NULL value will be returned, as there is no row below this one.

Above()--

values as they appear on the row above the current row within a column,

On the first row of a column segment a NULL value will be returned, as there is no row above this one

Re: Previous() and Peek()

manideep78 — Thu, 21 Feb 2013 09:09:58 GMT

Previous() - It always returns entire data except last record data.

Temp:
LOAD * INLINE [
    Emp_No, Emp_Name, Join_Date
    1, Manideep, 15-01-2013
    2, Pradeep, 16-02-2013
    3, Sandeep, 17-08-2012
    4, Navadeep, 19-06-2011
    5, Jayadeep, 16-12-2010
];
Previous:
LOAD Previous(Emp_Name) as Name        // It returns upto Navadeep
Resident Temp;
Nested_Previous:
LOAD Previous(Previous(Previous(Emp_Name))) as Name      // It returns only Manideep and Pradeep
Resident Temp;

Peek(): It returns the content of specified filed name.

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

E_Name:
LOAD Peek('Emp_Name',0,'Temp') as E_Name // It returns the first record. If we replace 0 with -1, it returns last record.
Resident Temp;

for more understanding see in help

Hope u got it now

Cheers

Re: Previous() and Peek()

hic — Thu, 21 Feb 2013 09:17:31 GMT

The main difference is that Previous() fetches data from previous input record, whereas Peek() fetches data from previous output record. (Input to the Load statement and output of the Load statement.)

In addition, Peek() can be used to fetch data from other records than the previous and from other tables than the current, if the second and third parameters are used.

HIC

Re: Previous() and Peek()

nagarajupinnibo — Thu, 21 Feb 2013 09:18:06 GMT

can anyone say about above() and below() functions with examples??