Are Databases Owned by a Login or a User? Updated FREE

Are Databases Owned by a Login or a User?

Skip to main content

Buying and user-schema separation in SQL Server

• Article
• 08/09/2021
• 3 minutes to read

Is this page helpful?

Feedback will exist sent to Microsoft: By pressing the submit button, your feedback volition exist used to amend Microsoft products and services. Privacy policy.

In this article

Applies to: SQL Server (all supported versions) Azure SQL Database Azure SQL Managed Case Azure Synapse Analytics Analytics Platform System (PDW)

A cadre concept of SQL Server security is that owners of objects have irrevocable permissions to administer them. Yous can't remove privileges from an object owner, and you can't drop users from a database if they own objects in it.

User-schema separation

User-schema separation allows for more flexibility in managing database object permissions. A schema is a named container for database objects, which allows you to grouping objects into separate namespaces. For example, the AdventureWorks sample database contains schemas for Production, Sales, and HumanResources.

The four-part naming syntax for referring to objects specifies the schema name.

              Server.Database.DatabaseSchema.DatabaseObject                          

Schema owners and permissions

Schemas can exist endemic by whatever database principal, and a single main tin own multiple schemas. You can apply security rules to a schema, which are inherited by all objects in the schema. Once you set up access permissions for a schema, those permissions are automatically applied as new objects are added to the schema. Users tin can exist assigned a default schema, and multiple database users can share the same schema.

By default, when developers create objects in a schema, the objects are owned by the security principal that owns the schema, not the developer. Object ownership tin can be transferred with ALTER Potency Transact-SQL statement. A schema can besides comprise objects that are owned by dissimilar users and have more than granular permissions than those assigned to the schema, although this isn't recommended considering it adds complication to managing permissions. Objects can be moved between schemas, and schema ownership can be transferred between principals. Database users tin be dropped without affecting schemas.

Built-in schemas for backward compatibility

SQL Server ships with nine pre-divers schemas that have the aforementioned names as the built-in database users and roles: db_accessadmin, db_backupoperator, db_datareader, db_datawriter, db_ddladmin, db_denydatareader, db_denydatawriter, db_owner, db_securityadmin. These exist for astern compatibility. The recommendation is to not utilise them for user objects. Yous tin can drop the schemas that take the same names equally the fixed database roles - unless they're already in employ, in which case the drop-command will merely return an error and cake the driblet of the used schema.

              IF EXISTS (SELECT * FROM sys.schemas WHERE name = Northward'db_accessadmin') DROP SCHEMA [db_accessadmin] Go  IF EXISTS (SELECT * FROM sys.schemas WHERE name = N'db_backupoperator') Drop SCHEMA [db_backupoperator] Go  IF EXISTS (SELECT * FROM sys.schemas WHERE name = N'db_datareader') Driblet SCHEMA [db_datareader] GO  IF EXISTS (SELECT * FROM sys.schemas WHERE proper noun = Northward'db_datawriter') DROP SCHEMA [db_datawriter] Go  IF EXISTS (SELECT * FROM sys.schemas WHERE name = N'db_ddladmin') Drop SCHEMA [db_ddladmin] Get  IF EXISTS (SELECT * FROM sys.schemas WHERE name = N'db_denydatareader') DROP SCHEMA [db_denydatareader] Become  IF  EXISTS (SELECT * FROM sys.schemas WHERE proper name = N'db_denydatawriter') DROP SCHEMA [db_denydatawriter] GO  IF  EXISTS (SELECT * FROM sys.schemas WHERE name = North'db_owner') DROP SCHEMA [db_owner] Go  IF EXISTS (SELECT * FROM sys.schemas WHERE name = N'db_securityadmin') DROP SCHEMA [db_securityadmin] GO                          

If you driblet these schemas from the model database, they won't appear in new databases. Schemas that contain objects cannot be dropped.

The following schemas cannot be dropped:

• dbo
• invitee
• sys
• INFORMATION_SCHEMA

Note

The sys and INFORMATION_SCHEMA schemas are reserved for system objects. Y'all cannot create objects in these schemas and you cannot drop them.

The dbo schema

The dbo schema is the default schema of every database. By default, users created with the CREATE USER Transact-SQL control accept dbo equally their default schema. The dbo schema is owned past the dbo user account.

Users who are assigned the dbo as default schema don't inherit the permissions of the dbo user account. No permissions are inherited from a schema by users; schema permissions are inherited past the database objects contained in the schema. The default schema for a user is solely used for object-reference in example the user omits the schema when querying objects.

Notation

When database objects are referenced by using a one-role proper name, SQL Server start looks in the user's default schema. If the object is non found there, SQL Server looks side by side in the dbo schema. If the object is not in the dbo schema, an fault is returned.

External resource

For more than data on object ownership and schemas, encounter the following resources.

Resource	Description
User-Schema Separation	Describes the changes introduced by user-schema separation. Includes new behavior, its impact on buying, catalog views, and permissions.

Run into also

• Protecting Your SQL Server Intellectual Property
• Getting Started with Database Engine Permissions
• Server-Level Roles
• Securing ADO.NET Applications

Feedback

Submit and view feedback for

Are Databases Owned by a Login or a User?

DOWNLOAD HERE

Source: https://docs.microsoft.com/en-us/sql/relational-databases/security/authentication-access/ownership-and-user-schema-separation

Posted by: molly-my8daily.blogspot.com

Share this

Related Posts