GIS & Databases Ming-Chun Lee

Object Relationships One-to-One One-to-Many Many-to-One Many-to-Many

Types of Databases Flat File Hierarchical Relational Single Table; No Relationships Hierarchical Nested Tables One-to-One & One-to-Many Relationships Relational Interrelated Tables One-to-One, One-to-Many, Many-to-One, Many-to-Many Relationships

Flat File Database ID Route Timepoint 1 Timepoint 2 … Timepoint 10 1 71 4th Ave. S & S Washington St. 5th Ave. S & S Jackson St. 50th Ave. NE & NE 75th St. 2 72 Ravenna Ave. NE & NE 80th St. 3 73 15th Ave. NE & NE 125th St.

Hierarchical Database TPID Timepoint 1 4th Ave. S & S Washington St. 2 5th Ave. S & S Jackson St. … 10 50th Ave. NE & NE 75th St. ID Route 1 71 2 72 3 73 TPID Timepoint 1 4th Ave. S & S Washington St. 2 5th Ave. S & S Jackson St. … 10 50th Ave. NE & NE 75th St. TPID Timepoint 1 4th Ave. S & S Washington St. 2 5th Ave. S & S Jackson St. … 10 15th Ave. NE & NE 125th St.

Relational Database ID Route 1 71 2 72 3 73 OID Route TP Order 101 71 102 2 110 10 201 72 202 210 301 73 302 310 TPID Timepoint 1 4th Ave. S & S Washington St. 2 5th Ave. S & S Jackson St. … 110 50th Ave. NE & NE 75th St. 210 Ravenna Ave. NE & NE 80th St. 310 15th Ave. NE & NE 125th St.

Relational Database Concepts One Table for Each Type of “Thing/Entity” Within a Table: One Row for Each Distinct “Thing” of that Type Primary Key: A Unique Identifier for the distinct “Thing” Foreign Key: A Reference to Another Table’s Primary Key

GIS as a Relational Database Join Tables to Spatial Data Layers User ID Name Abbrev. 10 Washington WA 12 Oregon OR 18 Michigan MI ID Area Perimeter User ID 1 25.3 10.4 10 2 30.2 13.5 12 3 10.1 8.2 18 4 27.8 12.6