1. Principles of GIS Fundamental database concepts – II Shaowen Wang
CyberInfrastructure and Geospatial Information Laboratory (CIGI)
Department of Geography and Geographic Information Science
Department of Computer Science
Department of Urban and Regional Planning
National Center for Supercomputing Applications (NCSA)
University of Illinois at Urbana-Champaign
September 12, 2013

2. Connecting to DB % ssh username@geo480.cigi.uiuc.edu Login to DB
Enter password
Help: %psql --help
Login to DB
% psql -U geog480 -d geog480db

3. Some Postgres Commands
List all accessible databases
# \l
Connect to a DB named 'geog480db'
# \c geog480db
List all the tables in current DB
# \dt, # \d (show all relations)‏
Quit
# \q

4. SQL Commands Create Tables Delete table
# create table test(key int, attr varchar(20), value float);
Delete table
# drop table test;

5. SQL Commands Insert a row Update table contents Delete rows
# insert into test values(1, 'attr0', 100);
Update table contents
# update test set attr='attr1' where key=1;
Delete rows
# delete from test where key=1;

6. SQL Commands List contents of table # select * from test;
# select * from test where attr='attr1';

7. Extended Entity-Relationship Model
Sub-type
Specialization
Super-type
Generalization
Inheritance

8. Object-Orientation
Object
State
Behavior
Class
Attributes
Method

9. O-O Features Encapsulation Inheritance and polymorphism
Reduces modeling complexity
Promotes reuse
Inheritance and polymorphism
Combats impedance mismatch
Metaphorical power

10. Relational Databases
Attribute
Tuple
Relation scheme
Relation

11. Relation ID
Candidate key
Primary key

12. Operations on Relations
Project
Restrict

13. Relational Algebra Derived relational operators Performance Join
Natural join
Performance

14. Extensible RDBMS RDBMS problems when handling spatial data
Data structure
Performance
Search

15. Logging into the system
% ssh
Login name: netid
Password: your password
% psql -U username –d tutorial
Login name: geog480
Password: same

16. End of This Class