User manual

Creating databases 37
For example, in the Clients table you might want to assign each client
a unique, identifying number. You wouldn’t enter a client
identification number into the table unless you had a new client to add,
so the existence of a client number determines the existence of a
record.
8. For each table, decide which fields will store data, and which ones
will be used from other (related) tables.
Each table has only one subject, and all fields in a table describe only
that subject.
For example, the fields in one record of the Clients table together
store all the information about one client.
Based on a table’s subject, you can see where it makes sense to store
the data and where to use data from a related table. Other than match
fields, all fields should appear only once in your database. Cross out
occurrences of fields that don’t pertain to the table’s subject.
9. Determine the relationships between the tables. In your plan, draw
a line from each match field in a table to the corresponding match
field in the related table.
What establishes a relationship between tables is that their match
fields contain matching data.
Relationships also make it possible to group your data to resolve
complex queries. For example, relationships can be used to
determine current inventory levels, sales projections, and other tasks
where it is necessary to query data across multiple tables. For more
information about relationships, see
chapter 3, “Working with
related tables and files.”
10. Determine whether you need to share your database with other
users, and how they will access the file.
For more information about sharing databases, see “Sharing
databases on a network” on page 73.
11. Consider who will use the database and whether you want to
restrict access to it. When you create the database, assign access
privileges as needed.
For more information about accounts and privilege sets, see
chapter 5, “Protecting databases with accounts and privilege sets.”
12. Decide what layouts you need, and plan a separate layout for
each task.
Client ID
Street
Postal Code
Client Name
City
Tour ID
Clients table
Routes table
Tour Name
Tours table
Phone
Route ID
Destination
Origin
Tour ID
Route ID
Destination
Tour Name
Origin
Client ID
Street
Postal Code
Client Name
City
Tour ID
Clients table
Routes table
Tour Name
Tours table
Phone
Route ID
Destination
Origin
Tour ID
Route ID
Destination
Tour Name
Origin