Preventing a field from being modified after entry if related data is changed in another table
Hi I'm new to database development and learning...I need assistance understanding how to prevent a field from being modified in a related table. So here is the senario, I have an employee entering a time card via a Filemaker Layout. We have multiple lists that I have created separate tables for such as 'Employee List', 'Job Lists', etc. Now we want to be able to update these lists as we lose and gain employees, and jobs. I have another table called 'Time Card' that will have a layout for time entry. I want the manager to be able to type in an employee number or begin typing a name and have a list of employees to select from and entered into 'Time Card'. I believe this makes it a one to many relation ship between the Time Card table and the other table lists. So I dont want a name to be changed in the time card table if say, an employee name changes. Is this a problem and how can I avoid this? Is this a problem that exists only in many to many relationships and if so how is that problem avoided...Thanks for any help...