Learning MySQL

Understanding Users and Privileges

MySQL, like most other database servers, has users who have privileges that determine whether they can create, modify, delete, and query databases, and also whether they can modify the privileges and control the server. In practice, this control can be coarse-grained—a user may be allowed or prevented from accessing the server—or fine-grained, where a user can access only some tables in a database or only some columns in a table. Some database servers support only coarse-grained control, while others such as MySQL allow both coarse-grained and fine-grained control over access.

MySQL allows you to control which users can access the server; the databases, tables, and columns on the server that they can access; and the types of actions that users can carry out on these structures. For example, MySQL allows you to explicitly control whether users can run the SELECT, UPDATE, INSERT, and DELETE statements, as well as whether they can LOCK TABLES, ALTER structures, or create and remove indexes. Most of the time, you’ll create users who can access and modify the data in a database but otherwise have no privileges to adjust the server configuration, change the database’s structure, or access other databases. We show you how to create different users and list all of the privileges later in this section.

MySQL users are distinct from the operating system users on the server computer. When you set up your machine, you automatically create superuser accounts ...