In this chapter, you will learn how to modify a column in an existing table, delete a table, and improve data retrieval time using indexes.
ALTER TABLE — Used to modify table definitions in an existing table.
DISALLOW NULL — Used to prevent null data from being inserted into a column.
IGNORE NULL — Used to cause null data in a table to be ignored for an index.
INDEX — Sorts and saves the values of a column in a different location on the computer with a pointer to the presorted records.
PRIMARY — Used to designate a column as a primary key.
UNIQUE — Used to ensure ...