Wednesday, September 23, 2009

Tables and relationships

To store your data, you create one table for each type of information that you track. Types of information might include customer information, products, and order details. To bring the data from multiple tables together in a query, form, or report, you define relationships between the tables.

1 Customer information that once existed in a mailing list now resides in the Customers table.
2 Order information that once existed in a spreadsheet now resides in the Orders table.
3 A unique ID, such as a Customer ID, distinguishes one record from another within a table. By adding one table's unique ID field to another table and defining a relationship between the two fields, Access can match related records from both tables so that you can bring them together in a form, report, or query.

Access database files

You can use Access to manage all of your information in one file. Within an Access database file, you can use:
  • Tables to store your data.
  • Queries to find and retrieve just the data that you want.
  • Forms to view, add, and update data in tables.
  • Reports to analyze or print data in a specific layout.

1 Store data once in one table, but view it from multiple locations. When you update the data, it's automatically updated everywhere it appears.
2 Retrieve data by using a query.
3 View or enter data by using a form.
4 Display or print data by using a report.

All of these items — tables, queries, forms, and reports — are database objects (database objects: An Access database contains objects such as tables, queries, forms, reports, pages, macros, and modules. An Access project contains objects such as forms, reports, pages, macros, and modules.).

Note: Some Access databases contain links to tables that are stored in other databases. For example, you may have one Access database that contains nothing but tables, and another Access database that contains links to those tables, as well as queries, forms, and reports that are based on the linked tables. In most cases, it does not matter whether a table is a linked table or actually stored in the database.