A database is a structured collection of data that provides multiple benefits over data that's stored in a flat file format, such as a shapefile or KML. These benefits include complex queries, complex relationships, scalability, security, data integrity, and transactions, to name a few. Using databases to store geospatial data is relatively easy, considering the aforementioned benefits.
Note
There are multiple types of database; however, the most common type of database, and the type of database that this chapter will cover, is the relational database.
A relational database stores data in tables. A table is composed of rows and columns, where each row is a single data record and each column stores a field value associated with each record. A table can have any number of records; however, each field is uniquely named and stores a specific type of data.
A data type restricts the information that can be stored in a field, and it is very important...