Tables are the basic building blocks of a diagram. Every diagram is made up of one or more tables
and various objects related to those tables.
Each table consists of a set of columns that contain the information about the type of data stored
in the table. Each column must be assigned a name, data type, and length. A table can also have a set
of foreign keys, constraints, rules and indexes. Since columns, indexes, constraints, rules and triggers are
defined for a specific table, they are treated as properties of that table in a database diagram.