RIGHT JOIN

• Join operation in SQL is used to combine multiple tables together into a single table.
• If we use the right join to combine two different tables, then we will get all the records from the right table. But we will get only those records from the left table, which have the corresponding key in the right table. Rest other records in the left table for which the common column value doesn’t match with the common column value of the right table; displayed as NULL.
• Let us take a look at the syntax of writing a query to perform the right join operation in SQL.

    SELECT TableName1.columnName1, TableName2.columnName2 FROM TableName1   

RIGHT JOIN TableName2 ON TableName1.ColumnName = TableName2.ColumnName;    

Now let us see take a deeper dive into the right join in SQL with the help of examples. All the queries in the examples will be written using the MySQL database.

Consider we have the following tables with the given data:

Table 1: employee

EmployeeID	Employee_Name	Employee_Salary
1	Arun Tiwari	50000
2	Sachin Rathi	64000
3	Harshal Pathak	48000
4	Arjun Kuwar	46000
5	Sarthak Gada	62000
6	Saurabh Sheik	53000
7	Shubham Singh	29000
8	Shivam Dixit	54000
9	Vicky Gujral	39000
10	Vijay Bose	28000

Table 2: department

DepartmentID	Department_Name	Employee_ID
1	Production	1
2	Sales	3
3	Marketing	4
4	Accounts	5
5	Development	7
6	HR	9
7	Sales	10

Table 3: Loan

LoanID	Branch	Amount
1	B1	15000
2	B2	10000
3	B3	20000
4	B4	100000
5	B5	150000
6	B6	50000
7	B7	35000
8	B8	85000

Table 4: Borrower

CustID	CustName	LoanID
1	Sonakshi Dixit	1
2	Shital Garg	4
3	Swara Joshi	5
4	Isha Deshmukh	2
5	Swati Bose	7
6	Asha Kapoor	10
7	Nandini Shah	9

Table 5: customer

Customer_ID	Name	Age	Salary
1	Aryan Jain	51	56000
2	Arohi Dixit	21	25000
3	Vineet Garg	24	31000
4	Ajeet Singh	23	32000
5	Ravi Rathod	23	42000
6	Paras Aggrawal	22	50000
7	Sonakshi Kapadiya	24	28000
8	Sonali Kapoor	28	82000

Table 6: orders

Order_ID	Order_Date	Cutomer_ID	Amount
1	2012-01-20	2	3000
2	2012-05-18	2	2000
3	2012-06-28	3	4000
4	2012-04-11	4	5000
5	2012-05-04	8	8000

Example 1:

Write a query to perform a right join operation considering the employee table as the left table and the department table as the right table.

Query:

mysql> SELECT e.EmployeeID, e.Employee_Name, e.Employee_Salary, d.DepartmentID, d.Department_Name FROM employee e RIGHT JOIN department d ON e.EmployeeID = d.Employee_ID;  

We have used the SELECT command to retrieve EmployeeID, Employee_Name, Employee_Salary, DepartmentID, Department_Name present in the employee and department table. Then we have used the RIGHT JOIN keyword to perform the right join operation on the employee and department table where ‘e’ and ‘d’ are aliases. These two tables are joined on the column EmployeeID which is present in both the tables.

You will get the following output:

EmployeeID	Employee_Name	Employee_Salary	DepartmentID	Department_Name
1	Arun Tiwari	50000	1	Production
3	Harshal Pathak	48000	2	Sales
4	Arjun Kuwar	46000	3	Marketing
5	Sarthak Gada	62000	4	Accounts
7	Shubham Singh	29000	5	Development
9	Vicky Gujral	39000	6	HR
10	Vijay Bose	28000	7	Sales

EmployeeID, Employee_Name, Employee_Salary, DepartmentID, Department_Name are retrieved from employee and department tables. All the records from the department table are retrieved. Only those records that have a corresponding EmployeeID in the department table are retrieved from the employee table.

Example 2:

Write a query to perform the right join operation considering the loan table as the left table and the borrower table as the right table.

Query:

mysql> SELECT l.LoanID, l.Branch, l.Amount, b.CustID, b.CustName FROM Loan l RIGHT JOIN Borrower b ON l.LoanID = b.LoanID;  

We have used the SELECT command to retrieve LoanID, Branch, Amount, CustID, CustName present in the loan and borrower table. Then we have used the RIGHT JOIN keyword to perform the right join operation on the loan and borrower table where ‘l’ and ‘b’ are aliases. These two tables are joined on the column LoanID which is present in both the tables.

You will get the following output:

LoanID	Branch	Amount	CustID	CustName
1	B1	15000	1	Sonakshi Dixit
4	B4	100000	2	Shital Garg
5	B5	150000	3	Swara Joshi
2	B2	10000	4	Isha Deshmukh
7	B7	35000	5	Swati Bose
NULL	NULL	NULL	6	Asha Kapoor
NULL	NULL	NULL	7	Nandini Shah

LoanID, Branch, Amount, CustID, CustName are retrieved from loan and borrower tables. All the records from the borrower table are retrieved. Only those records that have a corresponding LoanID in the borrower table are retrieved from the loan table. Rest other records in the loan table for which a LoanID doesn’t match with the LoanID of the borrower table, are displayed as NULL.

Example 3:

Write a query to perform a right join operation considering the customer table as the left table and the orders table as the right table.

Query:

mysql> SELECT c.Customer_ID, c.Name, c.Age, c.Salary, o.Order_ID, o.Order_Date, o.Amount FROM customer c RIGHT JOIN orders o ON c.Customer_ID = o.Customer_ID;  

We have used the SELECT command to retrieve Customer_ID, Name, Age, Salary, Order_ID, Order_Date, Amount present in customer and orders table. Then we have used the RIGHT JOIN keyword to perform the right join operation on the customer and orders table where ‘c’ and ‘o’ are aliases. These two tables are joined on the column Customer_ID which is present in both the tables.

You will get the following output:

Customer_ID	Name	Age	Salary	Order_ID	Order_Date	Amount
2	Arohi Dixit	21	25000	1	2012-01-20	3000
2	Arohi Dixit	21	25000	2	2012-05-18	2000
3	Vineet Garg	24	31000	3	2012-06-28	4000
4	Ajeet Singh	23	32000	4	2012-04-11	5000
8	Sonali Kapoor	28	82000	5	2012-05-04	8000

Customer_ID, Name, Age, Salary, Order_ID, Order_Date, Amount are retrieved from customer and orders tables. All the records from the orders table are retrieved. From the customer table, only those records which have a corresponding Customer_ID in the orders table are retrieved.