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
To delete the column named "DateOfBirth" in the "Persons" table you could use the following SQL statement:
ALTER TABLE Persons
DROP COLUMN DateOfBirth
Change Data Type
To change the data type of the column named "DateOfBirth" in the "Persons" table you could use the following SQL statement:
ALTER TABLE Persons
ALTER COLUMN DateOfBirth year