Alter & Drop

Adding a Field

To add a column in a table, use the following syntax:

ALTER TABLE table_name
ADD column_name datatype

Example:

ALTER TABLE Persons
ADD DateOfBirth date

Deleting a Field

Next, we want to delete the column named "DateOfBirth" in the "Persons" table.

We use the following SQL statement:

ALTER TABLE Persons
DROP COLUMN DateOfBirth

Change Data Type

Now we want to change the data type of the column named "DateOfBirth" in the "Persons" table.

We use the following SQL statement:

ALTER TABLE Persons
ALTER COLUMN DateOfBirth year