Update Substring of a field

Is it possible to update the substring of a field? I'm trying to do something like this: UPDATE tblIntervals SET SessionMouseID = 'ggg', substr(SessionID, 0, 3) = 'ggg' WHERE SessionMouseID = 'bbb'

Updating a Substring in a Field

Hello, Does Derby have a built in function that would allow me to do an SQL query to update a substring, something like this: UPDATE TABLE1 SET SUBSTRING(FieldName, original-substring, new-substring) WHERE FIELD1 = 'moose'