AutoCAD 2008 User's
Guide > Share Data Between
Drawings and Applications > Access External
Databases >
Overview of Using External Databases
When you link database records to graphical objects in a drawing, you can use powerful database queries to filter and sort information. You can present the results of a query graphically.
A database is a collection of logically related information, usually presented in a table format similar to a typical spreadsheet. The table below is an example of a simple database that might be used by a Facilities department to schedule maintenance work. It consists of four columns, or fields, labeled Maintenance task, Estimated hours, Frequency, and Assigned to. Individual fields, or cells, store data for a particular variable. Individual rows within the database table are called records.
|
Maintenance database table |
|||
|---|---|---|---|
|
Maintenance task |
Estimated hours |
Frequency |
Assigned to |
|
ELEVATOR SRV |
3.5 |
QUARTERLY |
RON SMITH |
|
CARPET VAC |
5.25 |
WEEKLY |
VICKI ROBERTS |
|
A/C CHECK |
2.00 |
BIWEEKLY |
AMY REED |
|
AIR FILTER |
3.00 |
MONTHLY |
DAT TAN |
Most database systems are extremely flexible and can be easily modified. You can add new fields or remove existing ones from database tables. Likewise, you can add or delete records from database tables and edit existing records. With many databases, you can also define relationships between multiple database tables. For example, suppose you have two database tables that share a common field, Room ID. Using a relational database, you can join these two database tables using their common field. You don't have to maintain and input duplicate data across multiple database tables.
You can use the program to associate data contained in an external database table with graphical objects through the process of linking. Links are pointers to a database table that reference data from one or more records in that table. You can also use the program to attach labels that display data from selected database table fields as text objects in your drawing.
The database connectivity feature provides the following:
