BIRT Designer: Determining Percentage of Total for Values in a Column

Question

I have a data set in BIRT Designer with two columns, one with day of week abbreviation names (Su, M, Tu, etc.) and the other with numerical representations of those days of the week starting at 0 and going to 6 (0, 1, 2, etc.). I want to determine what percentage of the total number of rows that each day of week represents. For example, if I have 100 total rows and 12 of those rows correspond to Su/0, 12% of the total rows are made up of Su.

I would like to perform this same calculation within BIRT and graph (bar graph) those percentages that each day consists of out of the total. I'm just learning how to use BIRT and assume that I need to do some scripting either when making my data set or when specifying the rows when making the chart. Any tips would be greatly appreciated.

Answer 1

With some inspiration from James Jenkins I think I found my answer. It was pretty simple in the end, but all I needed to do was make a new computed column and instead of adding an expression, I simply set the Aggregation to "COUNT". That counts all of the rows in your table and puts that total on each row. That way you can use that total in any calculations that you may need to do. I have added a screenshot for clarity.

Answer 2

Use computed columns.

Edit Data set > Computed Columns

The simplest way is to put one column that counts every row, for each day of the week. You can have a separate column that adds a count if the day of the week is a specific values

if (row["Day"] == "Su"){
1
}

I should add: that you can use a 'data' element in your table to compute the percentage. A 'Dynamic Text' item could also be used, but the data item gives you a binded value that you can make better use of later if needed.

Edit To get a total row count, us a computed column I name mine 'All'

For the Expression use the value "1"