Data Control Language - SQL Server to Aurora MySQL Migration Playbook
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Data Control Language

Feature compatibility Amazon SCT / Amazon DMS automation level Amazon SCT action code index Key differences


                              Four star feature compatibility


                              No automation

N/A

Difference.

SQL Server Usage

The ANSI standard specifies, and most Relational Database Management Systems (RDBMS) use GRANT and REVOKE commands to control permissions.

However, SQL Server also provides a DENY command to explicitly restrict access to a resource. DENY takes precedence over GRANT and is needed to avoid potentially conflicting permissions for users having multiple logins. For example, if a user has DENY for a resource through group membership but GRANT access for a personal login, the user is denied access to that resource.

SQL Server allows granting permissions at multiple levels from lower-level objects such as columns to higher level objects such as servers. Permissions are categorized for specific services and features such as the service broker.

Permissions are used in conjunction with database users and roles.

For more information, see Users and Roles.

Syntax

The following examples show the simplified syntax for SQL Server DCL commands:

GRANT { ALL [ PRIVILEGES ] } | <permission> [ ON <securable> ] TO <principal>
DENY { ALL [ PRIVILEGES ] } | <permission> [ ON <securable> ] TO <principal>
REVOKE [ GRANT OPTION FOR ] {[ ALL [ PRIVILEGES ] ]|<permission>} [ ON <securable> ] { TO | FROM } <principal>

For more information, see Permissions Hierarchy (Database Engine) in the SQL Server documentation.

MySQL Usage

Amazon Aurora MySQL-Compatible Edition (Aurora MySQL) supports the ANSI Data Control Language (DCL) commands GRANT and REVOKE.

Administrators can grant or revoke permissions for individual objects such as a column, a stored function, or a table. Administrators can grant permissions to multiple objects using wildcards.

Only explicitly granted permissions can be revoked. For example, if a user was granted SELECT permissions for the entire database using the following command:

GRANT SELECT
ON database.*
TO UserX;

It isn’t possible to REVOKE the permission for a single table. Instead, revoke the SELECT permission for all tables using the following command:

REVOKE SELECT
ON database.*
FROM UserX;

Aurora MySQL provides a GRANT permission option, which is very similar to the WITH GRANT OPTION clause in SQL Server. This permission gives a user permission to further grant the same permission to other users.

GRANT EXECUTE
ON PROCEDURE demo.Procedure1
TO UserY
WITH GRANT OPTION;
Note

Aurora MySQL users can have resource restrictions associated with their accounts similar to the SQL Server resource governor. For more information, see Resource Governor.

The following table identifies Aurora MySQL privileges:

Permissions Use to

ALL [PRIVILEGES]

Grant all privileges at the specified access level except GRANT OPTION and PROXY.

ALTER

Enable use of ALTER TABLE. Levels: Global, database, table.

ALTER ROUTINE

Enable stored routines to be altered or dropped. Levels: Global, database, procedure.

CREATE

Enable database and table creation. Levels: Global, database, table.

CREATE ROUTINE

Enable stored routine creation. Levels: Global, database.

CREATE TEMPORARY TABLES

Enable the use of CREATE TEMPORARY TABLE. Levels: Global, database.

CREATE USER

Enable the use of CREATE USER, DROP USER, RENAME USER, and REVOKE ALL PRIVILEGES. Level: Global.

CREATE VIEW

Enable views to be created or altered. Levels: Global, database, table.

DELETE

Enable the use of DELETE. Level: Global, database, table.

DROP

Enable databases, tables, and views to be dropped. Levels: Global, database, table.

EVENT

Enable the use of events for the Event Scheduler. Levels: Global, database.

EXECUTE

Enable the user to run stored routines. Levels: Global, database, table.

GRANT OPTION

Enable privileges to be granted to or removed from other accounts. Levels: Global, database, table, procedure, proxy.

INDEX

Enable indexes to be created or dropped. Levels: Global, database, table.

INSERT

Enable the use of INSERT. Levels: Global, database, table, column.

LOCK TABLES

Enable the use of LOCK TABLES on tables for which you have the SELECT privilege. Levels: Global, database.

PROXY

Enable user proxying. Level: From user to user.

REFERENCES

Enable foreign key creation. Levels: Global, database, table, column.

REPLICATION CLIENT

Enable the user to determine the location of primary and secondary servers. Level: Global.

REPLICATION SLAVE

Enable replication replicas to read binary log events from the primary. Level: Global.

SELECT

Enable the use of SELECT. Levels: Global, database, table, column.

SHOW DATABASES

Enable SHOW DATABASES to show all databases. Level: Global.

SHOW VIEW

Enable the use of SHOW CREATE VIEW. Levels: Global, database, table.

TRIGGER

Enable trigger operations. Levels: Global, database, table.

UPDATE

Enable the use of UPDATE. Levels: Global, database, table, column.

Syntax

GRANT <privilege type>...
ON [object type] <privilege level>
TO <user> ...
REVOKE <privilege type>...
ON [object type] <privilege level>
FROM <user> ...
Note

Table, Function, and Procedure object types can be explicitly stated but aren’t mandatory.

Examples

Attempt to REVOKE a partial permission that was granted as a wild card permission.

CREATE USER TestUser;
GRANT SELECT
    ON Demo.*
    TO TestUser;
REVOKE SELECT ON Demo.Invoices
    FROM TestUser

For the preceding example, the result looks as shown following.

SQL ERROR [1147][42000]: There is no such grant defined for user TestUser on host '%'
on table 'Invoices'

Grant the SELECT permission to a user on all tables in the demo database.

GRANT SELECT
ON Demo.*
TO 'user'@'localhost';

Revoke EXECUTE permissions from a user on the EmployeeReport stored procedure.

REVOKE EXECUTE
ON Demo.EmployeeReport
FROM 'user'@'localhost';

For more information, see GRANT Statement in the MySQL documentation.