SQL ALTER TABLE

The ALTER TABLE statement is used to add, modify or delete columns in an existing table. It is also used to rename a table.

You can also use SQL ALTER TABLE command to add and drop various constraints on an existing table.

SQL ALTER TABLE Add Column

If you want to add columns in SQL table, the SQL alter table syntax is given below:

If you want to add multiple columns in table, the SQL table will be

SQL ALTER TABLE Modify Column

If you want to modify an existing column in SQL table, syntax is given below:

If you want to modify multiple columns in table, the SQL table will be

SQL ALTER TABLE DROP Column

The syntax of alter table drop column is given below:

SQL ALTER TABLE RENAME Column

The syntax of alter table rename column is given below: