Basic Data Types of SQL
As previously mentioned, each column in a table has a data type. We review the major data types here.
Numeric
Numeric data types are data types that represent numbers. The following diagram provides an overview of some of the major types:
Figure 2.1: Major numeric data types
Character
Character data types store text information. The following diagram summarizes the character data types:
Figure 2.2: Major character data types
Under the hood, all of the character data types use the same underlying data structure in PostgreSQL and many other SQL databases, and most modern developers do not use char(n).
Boolean
Booleans are a data type used to represent True or False. The following table summarizes values that are represented as a Boolean when used in a query with a Boolean data column type:
Figure 2.3: Accepted Boolean values
While all of these values are accepted, the...