ZappySys Zoho API Driver can be used to update Zoho Records in Bulk. One tricky scenario is Updating Owners of records.
For this purpose, you can use Zoho ODBC Driver Created by ZappySys.
Here is the SQL Statment to Update ODD Records (look at id of row and do mod operation to check even or odd)
Even rows assign to sales-rep-1
UPDATE Accounts
SET Owner='{email: "sales-rep-1@abc.com"}'
WHERE substr(id,-1,1) % 2 =0
Odd rows assign to sales-rep-2
UPDATE Accounts
SET Owner='{email: "sales-rep-2@abc.com"}'
WHERE substr(id,-1,1) % 2 =1