The Related row lookup data type is for looking up the value of a cell in an already Related Row. Related row lookups can only be applied at the column level and only lookup data from rows that are already linked.
Once you have linked two sheets of data, the Related row lookup data type allows you to fill columns with data from the related sheet. For instance, in our related row article, New Blend related their interview tracker worksheet to their candidate tracking worksheet. Once two worksheets related, we can now then fill individual rows with the related team comments. In the animation below we see that we've already set up our related row, so Edit the data type of our "Interview Date" column, changing it to a Related row lookup. From the Update data type menu, we can select the specific column and data from our related worksheet to display. We pick date and the related cells now show us the interview date from our related worksheet.
Related row lookups help ensure that you are not duplicating data in multiple places. Instead, data can be kept in a single source of truth, related, and then you can lookup that data to display it on many worksheets. This ensures that if the data is changed in one sheet, this change is populated on all related sheets.
Related row lookups are helpful when you want to reference particular columns in other worksheets, especially if you have already related both sheets. Such as relating a worksheet for user feedback to a worksheet for bug tracking, or a worksheet on job postings to another on job candidates and still another tracking interviews.
By default, the Related row lookup data type has Strict enabled. Users cannot enter data into these cells, only populate them with lookups to related rows. To change the data that appears in a lookup, users must edit the data in the related worksheet. Either by expanding the related row, or navigating directly to the worksheet where the data originated.
Column to lookup from related worksheet
In the dialog box that appears when you change a column to a Related row lookup, you will see all available columns in the related row and can choose the column you want to look up data from. For instance, in the animation above we selected column E "Date" to populate our matching column of the same name.
If you do not yet know how to link worksheets, check out our article on related rows.