SQL ALTER TABLE statement have used to add and drop primary key of a table.

In this page we are going to discuss about the usage of SQL ALTER TABLE statement to add and drop foreign key of a table.

In this page we are going to discuss, how SQL FOREIGN KEY CONSTRAINT can be used to referring its own table in a CREATE TABLE statement.

In this page we are going to discuss, how SQL FOREIGN KEY CONSTRAINT can be used on more than one columns with primary key column list in a CREATE TABLE statement.

In this page it is going to be discussed that, how SQL FOREIGN KEY CONSTRAINT is used with primary key column list in a CREATE TABLE statement.

In this page we are going to discuss, how FOREIGN KEY CONSTRAINT can be used without specifying the primary key column(s).

In this page we are going to discuss the usage of FOREIGN KEY CONSTRAINT without using the 'foreign key' key word.

The SQL FOREIGN KEY CONSTRAINT is used to ensure the referential integrity of the data in one table to match values in another table

The SQL FOREIGN KEY CONSTRAINT is used to ensure the referential integrity of the data in one table to match values in another table.

In this page we are going to discuss about such a join, which is made up by using two tables which contain a composite PRIMARY KEY and FOREIGN KEY.