Beginning SQL

Chapter 12
Creating User IDs
Figure 12-2
The system administrator (SA) sets up users and defines the privileges those users have. In many cases,
this is done through a program interface to the DBMS, where the SA simply opens a form and starts creating
users, typing their initial password and telling the DBMS whether the user can change their password,
whether they must change their password the first time they log on, and so forth. In fact, some
DBMSs can allow all of the user/password validation to be performed by the OS, which means no user
IDs or passwords are required inside of the database itself.
Some DBMSs have SQL statements, extensions to the SQL standard specific to that DBMS, to allow creating
users. For example, in Oracle the statement looks like this:
CREATE USER username
IDENTIFIED {BY password | EXTERNALLY | GLOBALLY AS external_name}
Options
After creating users and determining privileges for those users, the SA can then alter users and privileges.
Alter User
330
Personal Depot
Group ID
Mary Sue John
User ID : usr Personnel
Personnel
Manager
Betty
User ID : usr Betty
Personnel
Dept Head
Cyndi
User ID : usr Cyndi
The SA can always modify the user by changing the password and, in some systems, by making a user
inactive or setting times of day or days of the week that the user can log in to the database. Some
DBMSs provide SQL statements for these functions. For example, in Oracle, the statement may look
like the following: