How to update a column with an int based on order after an editor event

Link to test case:
Debugger code (debug.datatables.net):
Error messages shown:
Description of problem:
How to update a column on all rows with an integer based on order after an editor event.
To be more precise, I would like to execute this SQL query :

set @sequenceNumber=0;
update itemsList
-> set itemOrder=(@sequenceNumber:=@sequenceNumber+1)
-> order by itemOrder ASC;