SQL Server logins and server roles

Permissions are the types of access granted to specific securables. At the server level, permissions are assigned to SQL Server logins and server roles. At the database level, they are assigned to database users and database roles.

You have three main ways to control permissions:
Grant — The GRANT statement enables principals to access specified securables.
Deny — The DENY statement prevents principals from accessing specified securables.
Revoke — The REVOKE statement eliminates permissions that were previously granted for specific securables.

Note that the DENY permissions statement overrides all granted permissions.

Securables are organized into a hierarchy comprised of servers, databases, schemas, and objects contained within those schemas. Permissions can be assigned at the server, database, schema or single object level.

Note that permissions granted at a higher level of the hierarchy automatically apply to lower levels, unless you specifically deny them to the securable’s children and grandchildren objects.


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