Upravit

Sdílet prostřednictvím

OPEN (Transact-SQL)

  • Článek

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

Opens a Transact-SQL server cursor and populates the cursor by executing the Transact-SQL statement specified on the DECLARE CURSOR or SET cursor_variable statement.

Transact-SQL syntax conventions

Syntax

OPEN { { [ GLOBAL ] cursor_name } | cursor_variable_name }

Arguments

GLOBAL
Specifies that cursor_name refers to a global cursor.

cursor_name
Is the name of a declared cursor. If both a global and a local cursor exist with cursor_name as their name, cursor_name refers to the global cursor if GLOBAL is specified; otherwise, cursor_name refers to the local cursor.

cursor_variable_name
Is the name of a cursor variable that references a cursor.

Remarks

If the cursor is declared with the INSENSITIVE or STATIC option, OPEN creates a temporary table to hold the result set. OPEN fails when the size of any row in the result set exceeds the maximum row size for SQL Server tables. If the cursor is declared with the KEYSET option, OPEN creates a temporary table to hold the keyset. The temporary tables are stored in tempdb.

After a cursor has been opened, use the @@CURSOR_ROWS function to receive the number of qualifying rows in the last opened cursor.

Note

SQL Server does not support generating keyset-driven or static Transact-SQL cursors asynchronously. Transact-SQL cursor operations such as OPEN or FETCH are batched, so there is no need for the asynchronous generation of Transact-SQL cursors. SQL Server continues to support asynchronous keyset-driven or static application programming interface (API) server cursors where low latency OPEN is a concern, due to client round trips for each cursor operation.

Examples

The following example opens a cursor and fetches all the rows.

DECLARE Employee_Cursor CURSOR FOR  
SELECT LastName, FirstName  
FROM AdventureWorks2022.HumanResources.vEmployee  
WHERE LastName like 'B%';  
  
OPEN Employee_Cursor;  
  
FETCH NEXT FROM Employee_Cursor;  
WHILE @@FETCH_STATUS = 0  
BEGIN  
    FETCH NEXT FROM Employee_Cursor  
END;  
  
CLOSE Employee_Cursor;  
DEALLOCATE Employee_Cursor;

See Also

CLOSE (Transact-SQL)
@@CURSOR_ROWS (Transact-SQL)
DEALLOCATE (Transact-SQL)
DECLARE CURSOR (Transact-SQL)
FETCH (Transact-SQL)