How to Rename Column Name in SQL?

Using the ALTER TABLE statement and the RENAME COLUMN clause, you can rename a column in SQL. Depending on the database management system (DBMS) you are using, the precise syntax for renaming a column may differ slightly.
Each DBMS has its own unique syntax. However, the fundamental idea is still the same.
Here is a systematic example of how to rename a column in SQL using the standard SQL syntax: Let us
assume we have a table named “employees” with the following structure and data:

Original table: “employees”

emp_id	first_name	last_name	department
1	John	Doe	HR
2	Harry	Smith	IT
3	Danielle	Pereira	Finance

Step 1: Connect to your database:

As soon as you are connected to your database using a SQL client or another program that supports running SQL queries, double-check that you have the appropriate rights to make changes to the table.

Step 2: Check the existing column names:

You can run the following query to confirm the current column names in the employee’s table:

DESCRIBE employees;
-- or --
SHOW COLUMNS FROM employees;

Step 3: Rename the column:

Now suppose you wish to give the department column the new name of dept. The following SQL statement will be used to rename the column:

-- Syntax for MySQL, MariaDB, and similar DBMSs:
ALTER TABLE employees
CHANGE COLUMN department dept VARCHAR(50);
-- Syntax for PostgreSQL:
ALTER TABLE employees
RENAME COLUMN department TO dept;
-- Syntax for SQL Server:
EXEC sp_rename 'employees.department', 'dept', 'COLUMN';
-- Syntax for Oracle:
ALTER TABLE employees
RENAME COLUMN department TO dept;

Note: If you wish to modify the data type of the column while renaming it, replace (VARCHAR(50)) with the proper data type for the column.

Step 4: Verify the changes:

To verify that the column name has been successfully renamed, you can execute the DESCRIBE or SHOW COLUMNS query again:

DESCRIBE employees;
-- or --
SHOW COLUMNS FROM employees;

The output should now show the updated column name:

Updated table: employees

emp_id	first_name	last_name	dept
1	John	Doe	HR
2	Harry	Smith	IT
3	Danielle	Pereira	Finance

That’s it! The column name has been successfully renamed in the table employees. Remember to use the appropriate syntax for your specific DBMS.