Difference between revisions of "Alter & Drop"
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To add a column in a table, use the following syntax: | To add a column in a table, use the following syntax: | ||
Revision as of 14:26, 24 December 2016
You will not be asked any questions to do with alter or drop in your exam, however it could be useful for projects.
==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
