PERMISSIONS (Transact-SQL)

Artikkeli
02/28/2023

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance

Returns a value containing a bitmap that indicates the statement, object, or column permissions of the current user.

Important

This feature will be removed in a future version of SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature. Use fn_my_permissions and Has_Perms_By_Name instead. Continued use of the PERMISSIONS function may result in slower performance.

Transact-SQL syntax conventions

Syntax

PERMISSIONS ( [ objectid [ , 'column' ] ] )

Arguments

objectid
Is the ID of a securable. If objectid is not specified, the bitmap value contains statement permissions for the current user; otherwise, the bitmap contains permissions on the securable for the current user. The securable specified must be in the current database. Use the OBJECT_ID function to determine the objectid value.

' column '
Is the optional name of a column for which permission information is being returned. The column must be a valid column name in the table specified by objectid.

Return Types

int

Remarks

PERMISSIONS can be used to determine whether the current user has the permissions required to execute a statement or to GRANT a permission to another user.

The permissions information returned is a 32-bit bitmap.

The lower 16 bits reflect permissions granted to the user, and also permissions that are applied to Windows groups or and fixed server roles of which the current user is a member. For example, a returned value of 66 (hex value 0x42), when no objectid is specified, indicates that the user has permission to execute the CREATE TABLE (decimal value 2) and BACKUP DATABASE (decimal value 64) statements.

The upper 16 bits reflect the permissions that the user can GRANT to other users. The upper 16 bits are interpreted exactly as those for the lower 16 bits described in the following tables, except they are shifted to the left by 16 bits (multiplied by 65536). For example, 0x8 (decimal value 8) is the bit that indicates INSERT permission when an objectid is specified. Whereas, 0x80000 (decimal value 524288) indicates the ability to GRANT INSERT permission, because 524288 = 8 x 65536.

Because of membership in roles, a user that does not have permission to execute a statement may still be able to grant that permission to another user.

The following table shows the bits that are used for statement permissions (objectid is not specified).

Bit (dec)	Bit (hex)	Statement permission
1	0x1	CREATE DATABASE (master database only)
2	0x2	CREATE TABLE
4	0x4	CREATE PROCEDURE
8	0x8	CREATE VIEW
16	0x10	CREATE RULE
32	0x20	CREATE DEFAULT
64	0x40	BACKUP DATABASE
128	0x80	BACKUP LOG
256	0x100	Reserved

The following table shows the bits used for object permissions that are returned when only objectid is specified.

Bit (dec)	Bit (hex)	Statement permission
1	0x1	SELECT ALL
2	0x2	UPDATE ALL
4	0x4	REFERENCES ALL
8	0x8	INSERT
16	0x10	DELETE
32	0x20	EXECUTE (procedures only)
4096	0x1000	SELECT ANY (at least one column)
8192	0x2000	UPDATE ANY
16384	0x4000	REFERENCES ANY

The following table shows the bits used for column-level object permissions that are returned when both objectid and column are specified.

Bit (dec)	Bit (hex)	Statement permission
1	0x1	SELECT
2	0x2	UPDATE
4	0x4	REFERENCES

A NULL is returned when a specified parameter is NULL or not valid (for example, an objectid or column that does not exist). The bit values for permissions that do not apply (for example EXECUTE permission, bit 0x20, for a table) are undefined.

Use the bitwise AND (&) operator to determine each bit set in the bitmap that is returned by the PERMISSIONS function.

The sp_helprotect system stored procedure can also be used to return a list of permissions for a user in the current database.

Examples

A. Using the PERMISSIONS function with statement permissions

The following example determines whether the current user can execute the CREATE TABLE statement.

IF PERMISSIONS()&2=2  
   CREATE TABLE test_table (col1 INT)  
ELSE  
   PRINT 'ERROR: The current user cannot create a table.';

B. Using the PERMISSIONS function with object permissions

The following example determines whether the current user can insert a row of data into the Address table in the AdventureWorks2022 database.

IF PERMISSIONS(OBJECT_ID('AdventureWorks2022.Person.Address','U'))&8=8   
   PRINT 'The current user can insert data into Person.Address.'  
ELSE  
   PRINT 'ERROR: The current user cannot insert data into Person.Address.';

C. Using the PERMISSIONS function with grantable permissions

The following example determines whether the current user can grant the INSERT permission on the Address table in the AdventureWorks2022 database to another user.

IF PERMISSIONS(OBJECT_ID('AdventureWorks2022.Person.Address','U'))&0x80000=0x80000  
   PRINT 'INSERT on Person.Address is grantable.'  
ELSE  
   PRINT 'You may not GRANT INSERT permissions on Person.Address.';

Jaa