sp_describe_cursor_tables (Transact-SQL)

Artikel
2024-07-05

Applies to: SQL Server

Reports the objects or base tables referenced by a server cursor.

Syntax

sp_describe_cursor_tables
    [ @cursor_return = ] cursor_return OUTPUT
    , [ @cursor_source = ] { N'local' | N'global' | N'*cursor_source*' }
    , [ @cursor_identity = ] N'cursor_identity'
[ ; ]

Arguments

[ @cursor_return = ] cursor_return OUTPUT

The name of a declared cursor variable to receive the cursor output. @cursor_return is an OUTPUT cursor, with no default, and must not be associated with any cursors at the time sp_describe_cursor_tables is called. The cursor returned is a scrollable, dynamic, read-only cursor.

[ @cursor_source = ] { N'local' | N'global' | N'cursor_source' }

Specifies whether the cursor being reported on is specified by using the name of a local cursor, a global cursor, or a cursor variable. @cursor_source is nvarchar(30), with no default.

[ @cursor_identity = ] N'cursor_identity'

When @cursor_source is local, @cursor_identity is the name of a cursor created by a DECLARE CURSOR statement either having the LOCAL keyword, or that defaulted to LOCAL.

When @cursor_source is global, @cursor_identity is the name of a cursor created by a DECLARE CURSOR statement either having the GLOBAL keyword, or that defaulted to GLOBAL. @cursor_identity can also be the name of an API server cursor opened by an ODBC application that then named the cursor by calling SQLSetCursorName.

When @cursor_source is variable, @cursor_identity is the name of a cursor variable associated with an open cursor.

@cursor_identity is nvarchar(128), with no default.

Return code values

None.

Cursors returned

sp_describe_cursor_tables encapsulates its report as a Transact-SQL cursor output parameter. This enables Transact-SQL batches, stored procedures, and triggers to work with the output one row at a time. This also means that the procedure can't be called directly from API functions. The cursor output parameter must be bound to a program variable, but the APIs don't support bind cursor parameters or variables.

The following table shows the format of the cursor that is returned by sp_describe_cursor_tables.

Column name	Data type	Description
`table_owner`	sysname	User ID of the table owner.
`table_name`	sysname	Name of the object or base table. In SQL Server, server cursors always return the user-specified object, not the base tables.
`optimizer_hint`	smallint	Bitmap that is made up of one or more of the following options: 1 = Row-level locking (`ROWLOCK`) 4 = Page-level locking (`PAGELOCK`) 8 = Table lock (`TABLOCK`) 16 = Exclusive table lock (`TABLOCKX`) 32 = Update lock (`UPDLOCK`) 64 = No lock (`NOLOCK`) 128 = Fast first-row option (`FASTFIRST`) 4096 = Read repeatable semantic when used with `DECLARE CURSOR` (`HOLDLOCK`) When multiple options are supplied, the system uses the most restrictive. However, `sp_describe_cursor_tables` shows the flags that are specified in the query.
`lock_type`	smallint	Scroll-lock type requested either explicitly or implicitly for each base table that underlies this cursor. The value can be one of the following options: 0 = None 1 = Shared 3 = Update
`server_name`	sysname, nullable	Name of the linked server that the table resides on. `NULL` when `OPENQUERY` or `OPENROWSET` are used.
`objectid`	int	Object ID of the table. 0 when `OPENQUERY` or `OPENROWSET` are used.
`dbid`	int	ID of the database that the table resides in. 0 when `OPENQUERY` or `OPENROWSET` are used.
`dbname`	sysname, nullable	Name of the database that the table resides in. `NULL` when `OPENQUERY` or `OPENROWSET` are used.

Remarks

sp_describe_cursor_tables describes the base tables referenced by a server cursor. For a description of the attributes of the result set returned by the cursor, use sp_describe_cursor_columns. For a description of the global characteristics of the cursor, such as its scrollability and updatability, use sp_describe_cursor. To obtain a report of the Transact-SQL server cursors that are visible on the connection, use sp_cursor_list.

Permissions

Requires membership in the public role.

Examples

The following example opens a global cursor and uses sp_describe_cursor_tables to report on the tables referenced by the cursor.

USE AdventureWorks2022;
GO
-- Declare and open a global cursor.
DECLARE abc CURSOR KEYSET FOR
SELECT LastName
FROM Person.Person
WHERE LastName LIKE 'S%';

OPEN abc;
GO
-- Declare a cursor variable to hold the cursor output variable
-- from sp_describe_cursor_tables.
DECLARE @Report CURSOR;

-- Execute sp_describe_cursor_tables into the cursor variable.
EXEC master.dbo.sp_describe_cursor_tables
    @cursor_return = @Report OUTPUT,
    @cursor_source = N'global',
    @cursor_identity = N'abc';

-- Fetch all the rows from the sp_describe_cursor_tables output cursor.
FETCH NEXT from @Report;
WHILE (@@FETCH_STATUS <> -1)
BEGIN
   FETCH NEXT from @Report;
END

-- Close and deallocate the cursor from sp_describe_cursor_tables.
CLOSE @Report;
DEALLOCATE @Report;
GO

-- Close and deallocate the original cursor.
CLOSE abc;
DEALLOCATE abc;
GO

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