[SOLVED] Open Refine - Regroup rows values by column values

Open Refine - Regroup rows values by column values

I am new Open refine user and don't know how to code.

I would like to group multiple values of a column compared to an other column.

I have this file

ID 1	ID 2
ID1.1	ID2.1
ID1.1	ID2.2
ID1.2	ID2.3
ID1.2	ID2.4
ID1.2	ID2.5

And i'd like to have this one :

ID 1	ID 2
ID1.1	ID2.1;ID2.2
ID1.2	ID2.3;ID2.4;ID2.5

The file got 150k lines and multiple columns

I tried to Add a new column based on the first column, but I don't how to group the values of the row1, row2, row3... of the second column based on the value of the first column.

Thank you for any answer

Solution

Switch to record mode by using blank down on the column ID 1
Use the following GREL in ID 2 with forEach(row.record.cells['ID 2'].value,v,v).join(';') to join data in the first cell
Delete the unwanted record by going back to rows mode, and bulk editing row where ID 1 is blank

Video recording of the steps: https://youtu.be/p6urT-CO76s