Join Operations:In a relational database, a join operation is used to combine data from two or more tables based on a common attribute or set of attributes. There are several types of join operations, including:
Inner Join: Returns only the rows that have matching values in both tables being joined.
Left Outer Join: Returns all rows from the left table and only the matching rows from the right table. If there are no matching rows in the right table, the result will contain NULL values for the right table columns.
Right Outer Join: Returns all rows from the right table and only the matching rows from the left table. If there are no matching rows in the left table, the result will contain NULL values for the left table columns.
Full Outer Join: Returns all rows from both tables, along with NULL values for any columns that do not have a matching value in the other table.
Set Operations:Set operations are used to combine two or more sets of data into a single result set. The common set operations in a relational database are:
Union: Returns all the distinct rows from both tables.
Intersection: Returns only the common rows between two tables.
Difference: Returns all the rows from one table that do not exist in the other table.
Cartesian Product: Returns all possible combinations of the rows from both tables.
Set operations can be used to perform various operations on data such as combining data from different sources, eliminating duplicate values, and comparing data sets. They are often used in combination with join operations to produce more complex queries in a relational database.
