EDUCBA Logo

EDUCBA

MENUMENU
  • Explore
    • EDUCBA Pro
    • PRO Bundles
    • Featured Skills
    • New & Trending
    • Fresh Entries
    • Finance
    • Data Science
    • Programming and Dev
    • Excel
    • Marketing
    • HR
    • PDP
    • VFX and Design
    • Project Management
    • Exam Prep
    • All Courses
  • Blog
  • Enterprise
  • Free Courses
  • Log in
  • Sign Up
Home Data Science Data Science Tutorials QlikView Tutorial Peek Function in QlikView
 

Peek Function in QlikView

Priya Pedamkar
Article byPriya Pedamkar

Updated March 23, 2023

Peek Function in QlikView

 

 

Introduction to Peek Function in QlikView

The peek() function acts as a scripting function in QlikView. This function is an inter-record function that allows the user to peek into previously read records of a table and use its values to evaluate a condition or to affect the record that is being read. To put it in simple words, the peek() function fetches the value of a field from a previous record which could be further used in calculations. The row number and the table can be specified.

Watch our Demo Courses and Videos

Valuation, Hadoop, Excel, Mobile Apps, Web Development & many more.

Syntax:

Peek(field_name[, row_no[, table_name ] ] )

Arguments:

Argument Description
field_name The name of the field for which the return value is required. The input value must be given as a string (for example, ‘Sales Volume’).
row_no The row in the table that specifies the field required. This can be an expression but should resolve to an integer. 0 indicates the first record, 1 for the second record and so on. Negative values denote order from the end of the table. -1 denotes the previous record read. If no row_no is stated, -1 is assumed by default
table_name Table label without the ending colon. If table_name is not specified, the current table is assumed. In the case of referring to another table or using outside the LOAD statement, the table_name must be included.

Example:

peek('Profit')
Returns the value of Profit in the previous record read (equivalent to previous(Profit)).

peek('Profit',2)
Returns the value of Profit from the third record read from the current input table.

Example of Peek Function in QlikView

Here is the example is given step by step

Step 1: Input Data

Let us create an excel file with the monthly profit of an organization as shown below and save the file in an excel format as ‘monthly_profit.xlsx’.

input data

Step 2: Load Script

Press CTRL+E to open the script editor or it could also be directly opened by clicking on the script editor icon in the File Menu. The data is loaded to QlikView memory by using the script editor. When opened the script looks as shown below.

LOAD Month,
Profit
FROM
[C:\Users\smoham87\Desktop\monthly_profit.xlsx] (ooxml, embedded labels);

Now, we need to add the peek() function to the script as shown is the example below.

LOAD Month,
Profit,
peek('Profit') as PrevMonth
FROM
[C:\Users\smoham87\Desktop\monthly_profit.xlsx] (ooxml, embedded labels);

Click on Ok and try to reload the script. You will find that the new variable ‘PrevMonth’ will be created as shown in the figure below.

Peek Function in QlikView - Load Script

Step 3: Creating Sheet Object

Lets us create a Table Box as an example to show how the data is generated by using the peek() script (Layout -> New Sheet Object -> Table Box). You will find the window as shown in the figure below.

Peek Function in QlikView - Creating Sheet Object

Enter the Title for the sheet object and select the required fields to be displayed and click OK. You will find the table box created as below. (You can later Sort the month column to list the months in sequence, in case they appear to be shuffled)

monthly profit table

The Previous Month value for January appears to be Null as we do not have data prior to January.

Step 4: Using the peek() Function in Calculations

The peek() function can also be used in calculations involving various other columns. Let us now calculate the percentage change in the profits for each month and display it in the table box.

Open the script editor and edit the script as shown below and click OK.

LOAD Month,
Profit,
peek('Profit') as PrevMonth,
(([Profit]-peek('Profit')))/peek('Profit')*100  as Difference
FROM
[C:\Users\smoham87\Desktop\monthly_profit.xlsx] (ooxml, embedded labels);

In the above script, we are creating a new variable that calculates the percentage change in the profit and assigning it to the variable name called ‘Difference’.

Step 5: Creating Sheet Object

Let us edit the existing Table Box we created earlier and add the ‘Difference’ column to it.

To edit the table box ‘Right Click’ on the table and click on ‘Properties’.  The ‘Table Box Properties’ window will open as shown in the figure below.

Peek Function in QlikView - Creating Sheet Object 2

Add the ‘Difference’ variable to ‘Fields Displayed in Tablebox’ and click OK.

You will find the table box as below added with the new column showing the percentage change.

monthly profit table.2

Peek() vs Previous() – By now, there may be some of you who might have already used the Previous() function in QlikView and might be wondering what is the difference between the two.

The answer to that is that in most cases QlikView offers the developers to accomplish a task in more than one way. It has a lot of useful functions that at times are not used. It depends on us to use the right function in the right place. In this case, there are surely a few similarities between the two functions, but we also need to consider the differences that need to be considered while deciding the function we need to use.

Similarities

  1. The two functions are used to read previously recorded rows in a table.
  2. The two functions can be programmed further to not only read the last row but also read previously recorded rows.

Difference

The Previous() function runs on the Input and Peek() function runs on the Output of the Load statement. In the previous() function the data is directly loaded from the source which enables to refer even to the fields that have not been previously loaded in QlikView (it will work even if the associative database does not contain the loaded data). This will result in different behavior while we use a ‘where-clause’.

When to use Peek() function?

The peek() function should ideally be used when the user wants a field that has not been previously recorded into the table or if a specific row is targeted.

Conclusion

The Peek() function is not just limited to reading the previously loaded records from the table we are currently processing, but it can also read a specific field from any row in any previously loaded table.

Recommended Articles

This is a guide to Peek Function in QlikView. Here we discuss the Example of Peek Function in QlikView along with the similarities and differences. You may also have a look at the following articles to learn more –

  1. QlikView Alternatives
  2. QlikView Functions
  3. Python Main Method
  4. Hashing Function in PHP
  5. Learn the Examples of ord Function in Python

Primary Sidebar

Footer

Follow us!
  • EDUCBA FacebookEDUCBA TwitterEDUCBA LinkedINEDUCBA Instagram
  • EDUCBA YoutubeEDUCBA CourseraEDUCBA Udemy
APPS
EDUCBA Android AppEDUCBA iOS App
Blog
  • Blog
  • Free Tutorials
  • About us
  • Contact us
  • Log in
Courses
  • Enterprise Solutions
  • Free Courses
  • Explore Programs
  • All Courses
  • All in One Bundles
  • Sign up
Email
  • [email protected]

ISO 10004:2018 & ISO 9001:2015 Certified

© 2025 - EDUCBA. ALL RIGHTS RESERVED. THE CERTIFICATION NAMES ARE THE TRADEMARKS OF THEIR RESPECTIVE OWNERS.

EDUCBA

*Please provide your correct email id. Login details for this Free course will be emailed to you
Loading . . .
Quiz
Question:

Answer:

Quiz Result
Total QuestionsCorrect AnswersWrong AnswersPercentage

Explore 1000+ varieties of Mock tests View more

EDUCBA

*Please provide your correct email id. Login details for this Free course will be emailed to you
EDUCBA
Free Data Science Course

Hadoop, Data Science, Statistics & others

By continuing above step, you agree to our Terms of Use and Privacy Policy.
*Please provide your correct email id. Login details for this Free course will be emailed to you
EDUCBA

*Please provide your correct email id. Login details for this Free course will be emailed to you

EDUCBA Login

Forgot Password?

🚀 Limited Time Offer! - 🎁 ENROLL NOW