The community of Analytics developers are invited to follow and participate in the developer network.
OpenText technical experts collaborate with supported customers and partners in the Magellan product area.

Compare current row with previous row value

I am new to developing reports in BIRT. can someone help me in determining how to obtain previous row value. I want to compare current row value with previous row value. There are three columns in my report. I have grouped the data on first column and the detail rows has first, second and third column. It is the second column on which I want to compare current row with previous row value. Lets call the second column as Shifttime and it's a date time data type attribute


  • VirgilVirgil Administrator EM admin
    edited October 18, 2017

    You could use a computed column on your data set to hold the previous row value in a persistent variable. There is an example in these forums at

    Virgil Dodson
    OpenText Analytics Developer Community

  • Thanks I did that, but it returned some random values (It did not return previous row values but random values from the dataset). I have used a group by on one of the columns and have sorting applied on that column in ascending manner. Did that cause this to return random results. The expression I used in the computed column is below: (Day is my base column for which I want previous values to return, it's a integer data type). Appreciate your response!

    Prevval (computed column) has following expression:
    var currentRow = row["Day"]; //Get current data row

    var previousRow = reportContext.getGlobalVariable("previousRow"); //Get global variable value

    if(currentRow==null){reportContext.setGlobalVariable("previousRow",null);} //Check for null and set null

    else{reportContext.setGlobalVariable("previousRow",currentRow);} //Or assign global variable to current row value

Sign In or Register to comment.