Alter Command in SQL
Alter command in SQL is used to add, delete, or modify columns in an existing table. Alter in SQL is will help to make changes in the existing columns like add columns or delete columns.
Watch this Alter Command in SQL Tutorial video
Alter Table Add Column
To add a column in an existing table.
ALTER TABLE table_name ADD column_name datatype;
Alter Table Drop Column
To delete a column from a table.
ALTER TABLE table_name DROP COLUMN column_name;
Example of Alter Query in SQL
In this example we will look at how to add a column “Year” in a Student_details table.
ALTER TABLE Student_details ADD Year int;