In this article, we will learn how to create and delete Indexes in SQL.
To create indexes in tables, the CREATE INDEX statement is used.
In this article, we will learn how to add a column with default value using the DEFAULT constraint in SQL.
To provide a default value for a column, the DEFAULT constraint is used.
In this article, we will learn how to use the CHECK constraint in SQL.
To limit the value range that can be placed in a column, the CHECK constraint is used.
In this article, we will learn how to use the Foreign Key constraint in SQL.
A FOREIGN KEY is a key, used to link tables together.
In this article, we will learn how to use the Primary Key constraint in SQL.
The PRIMARY KEY constraint is used to identify each record uniquely in a table.
In this article, we will learn how to use the UNIQUE constraint in SQL.
The UNIQUE constraint is used to ensure that all values in a column are different.
In this article, we will learn how to use the NOT NULL constraint in SQL.
A column can hold NULL values by default. The NOT NULL constraint is used to enforce a column to NOT accept NULL values.
