From Xojo Documentation
Call to update the RecordSet to reflect changes to the record the record pointer is pointing to.
Some databases do not allow you to update if the SQL statement used to get the RecordSet contains more than one table. Additionally, some databases may require that the SQL statement specifically include the Primary Key for the table.
Updating with MySQL
MySQL cannot guarantee the contents of a RecordSet after issuing an Update call (after having previously called Edit). This means you should not try to modify the contents of a RecordSet in a loop. Instead select just the single record you wish to modify.
Set the string value of a column in a RecordSet: