SQL DROP COLUMN

The DROP COLUMN statement in SQL is used to remove an existing column from a table.

 

Key Features of SQL DROP COLUMN

• Deletes a column permanently from a table.
• Cannot be undone unless backed up.
• Can drop multiple columns in a single query (supported in some databases).

 

SQL DROP COLUMN Syntax

ALTER TABLE table_name 
DROP COLUMN column_name;

 

Example: Dropping a Single Column

ALTER TABLE Employees 
DROP COLUMN Email;

• Removes the Email column from the Employees table.

 

Example: Dropping Multiple Columns (MySQL, PostgreSQL)

ALTER TABLE Employees 
DROP COLUMN Age, 
DROP COLUMN Address;

• Removes Age and Address columns from the Employees table.

 

Example: Dropping a Column in SQL Server

ALTER TABLE Employees 
DROP COLUMN Status;

• Removes the Status column in SQL Server.

 

Summary

• DROP COLUMN permanently removes a column from a table.
• Some databases allow dropping multiple columns at once.
• Ensure there is no dependency on the column before dropping it.
• Backup data before performing this action.