ALTERNATE KEY IN SQL

Alternate key is a secondary key it can be simple to understand by an example: Let?s take an example of student it can contain NAME, ROLL NO., ID and CLASS. …

UNIQUE KEY IN SQL

A unique key is a set of one or more than one fields/columns of a table that uniquely identify a record in a database table. You can say that it is little like …

SQL COMPOSITE KEY

A composite key is a combination of two or more columns in a table that can be used to uniquely identify each row in the table when the columns are combined …

SQL FOREIGN KEY

In the relational databases, a foreign key is a field or a column that is used to establish a link between two tables. In simple words you can say that, a …

SQL PRIMARY KEY

A column or columns is called primary key (PK) that uniquely identifies each row in the table. If you want to create a primary key, you should define a PRIMARY …

SQL CROSS JOIN

When each row of first table is combined with each row from the second table, known as Cartesian join or cross join. In general words we can say that SQL CROSS …

SQL FULL JOIN

The SQL full join is the result of combination of both left and right outer join and the join tables have all the records from both tables. It puts NULL on the …

SQL RIGHT JOIN

The SQL right join returns all the values from the rows of right table. It also includes the matched values from left table but if there is no matching in both …

SQL LEFT JOIN

The SQL left join returns all the values from the left table and it also includes matching values from right table, if there are no matching join value it …

SQL OUTER JOIN

In the SQL outer JOIN all the content of the both tables are integrated together either they are matched or not. If you take an example of employee table Outer …