Table design screen Data type Field name Field

Table design screen Data type Field name Field size Other properties

Datasheet View

Relationships screen Tables One-to-Many relationships

Elements of a database application • Tables - for storing data • Forms - screen layouts for entering and viewing data • Queries - for asking questions about the data • Reports - for printed output

To consider in table design In creating fields: Does the field identify items (eg customer name) or inform people about them? (eg age) or do both? (eg address) Which item is the unique identifier - the key? (cust no) What data type is appropriate for the field? (cust no = num, cust name = alp) What additional properties should the field have? (cust no: size = 3, required = yes)

Are these fields identifiers or informational? Electricity/gas company customer number. ID Bank account number. ID Book title in library catalogue. ID/INF Class mark of book in library. ID/INF Date your overdue book or bill is due. INF Current level of funds in your account. INF Module name: e. g. Information Systems Development and Practice 1. ID/INF Module number: e. g. UQI 114 S 1. ID/INF

Key fields uniquely identify each record in the table If no one field is a unique identifier then either: - create a new identifier (eg cust no) or -make a key from two or more fields (eg first name + second name)