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What we’ve learnt Doc 5.69 Doc 5.70 Section 1-3 A simple database • Related objects • Tables hold the data • Forms, reports, queries to access the data Database FADS • Create FADS • Create object in FADS, e.g Owners table, Ownersphone query • Don’t need to create a new database for each new object • Database FADS is container for objects Wizards can help • Tables for standard components e.g customers • You can customise the standard components • Report wizard generates reports • Form Wizard generates forms About tables • Tell you about things (entities) • Entities have characteristics (attributes) such as names, addresses, ages • Attributes are represented by fields in the table • Fields have data type - e.g number, dates. • Access 97 provides default types, sizes you can change them. Keys • Data in the table is held in records • Each record must have a unique identifier Primary Key • Relationships between tables are represented by Foreign Keys • e.g Cats table has a field Ownerid • Ownerid is the primary key (unique identifier) of the owner in the Owners table. Data Model Diagram Cats Owners Bookings Queries that join tables • Need data about Owners and Cats • Vacbooster is a query that joins data from two tables • Temporary data - called a dynaset • Doesn’t change the data in the tables Joining Tables • Relationships allow you to combine data about more than one thing. • E.g Cats and Owners, Students and staff, Suppliers and products. • Owners/Cats relationship is Each Owner can own one or more cats • One to Many relationship • Must include the unique identifier of the one as foreign key in many