Exploring Types of Constraints
Now, you'll study the different types of constraints that can be created on database tables. Following is a list of those constraints:
Each of these constraints have their own function. The functions and syntax of each of these constraints are discussed in the following subsections, as well as their place in a relational database.
NOT NULL Constraints
When you initially create a table, you must assign a data type to each column in the table. The data type assigned to a column tells the database what kind of data can be inserted into that column in a table. The different types of data mainly include Character data, Numeric data, and Date and Time data.
A basic CREATE TABLE ...