In PostgreSQL, the RETURNING clause is a powerful feature that allows you to return data from rows that are modified by INSERT, UPDATE, or DELETE statements. This feature is particularly useful when you need to retrieve the values of certain columns after an operation, without the need for a separate SELECT query.
What's New in the Latest PostgreSQL Release Regarding RETURNING:
In the latest PostgreSQL releases (up to version 15 as of the last update), the RETURNING clause has seen continued support and minor enhancements. Here's what you should know:
1. Enhanced Performance:
- PostgreSQL has made continuous improvements in query performance, which indirectly benefits the use of the RETURNING clause. The optimizer and execution plans have been fine-tuned, making operations that involve RETURNING more efficient in specific scenarios.
2. Expanded Use Cases:
- The RETURNING clause continues to support more complex expressions and functions, giving users the flexibility to return computed values, rather than just direct column data.
3. Use with Common Table Expressions (CTEs):
- PostgreSQL supports using the RETURNING clause within Common Table Expressions (CTEs). This allows for more complex operations where you can chain multiple INSERT, UPDATE, or DELETE operations while capturing and using the returned data within the same query.
Basic Examples of RETURNING Usage:-
INSERT with RETURNING:
INSERT INTO employees (name, position, salary)
VALUES ('John Doe', 'Manager', 75000)
RETURNING id, name, position;
- This returns the id, name, and position of the newly inserted row.
UPDATE with RETURNING:
UPDATE employees
SET salary = salary * 1.1
WHERE position = 'Manager'
RETURNING id, name, salary;
- This updates the salary of all employees with the position 'Manager' and returns their id, name, and the new salary.
DELETE with RETURNING:
DELETE FROM employees
WHERE id = 10
RETURNING id, name;
- This deletes the employee with id 10 and returns the id and name of the deleted employee.
The RETURNING feature in PostgreSQL continues to be a robust tool for developers. While there haven't been groundbreaking changes specifically to this feature in the latest releases, it remains a critical part of PostgreSQL's capabilities, enhanced by the general improvements in performance, support for complex expressions, and integration with other SQL features like CTEs.
