ISO Syntax DECLARE cursor_name [ INSENSITIVE ] [ SCROLL ] CURSOR FOR select_statement [ FOR { READ ONLY | UPDATE [ OF column_name [ ,...n ] ] } ] [;] Transact-SQL Extended Syntax DECLARE cursor_name CURSOR [ LOCAL | GLOBAL ] [ FORWARD_ONLY | SCROLL ] [ STATIC | KEYSET | DYNAMIC | FAST_FORWARD ] [ READ_ONLY | SCROLL_LOCKS | OPTIMISTIC ] [ TYPE_WARNING ] FOR select_statement [ FOR UPDATE [ OF column_name [ ,...n ] ] ] [;]
example:
SET NOCOUNT ON; DECLARE @vendor_id int, @vendor_name nvarchar(50), @message varchar(80), @product nvarchar(50); PRINT '-------- Vendor Products Report --------'; DECLARE vendor_cursor CURSOR FOR SELECT VendorID, Name FROM Purchasing.Vendor WHERE PreferredVendorStatus = 1 ORDER BY VendorID; OPEN vendor_cursor FETCH NEXT FROM vendor_cursor INTO @vendor_id, @vendor_name WHILE @@FETCH_STATUS = 0 BEGIN PRINT ' ' SELECT @message = '----- Products From Vendor: ' + @vendor_name PRINT @message -- Declare an inner cursor based -- on vendor_id from the outer cursor. DECLARE product_cursor CURSOR FOR SELECT v.Name FROM Purchasing.ProductVendor pv, Production.Product v WHERE pv.ProductID = v.ProductID AND pv.VendorID = @vendor_id -- Variable value from the outer cursor OPEN product_cursor FETCH NEXT FROM product_cursor INTO @product IF @@FETCH_STATUS <> 0 PRINT ' <<None>>' WHILE @@FETCH_STATUS = 0 BEGIN SELECT @message = ' ' + @product PRINT @message FETCH NEXT FROM product_cursor INTO @product END CLOSE product_cursor DEALLOCATE product_cursor -- Get the next vendor. FETCH NEXT FROM vendor_cursor INTO @vendor_id, @vendor_name END CLOSE vendor_cursor; DEALLOCATE vendor_cursor;
(2)對於可更新遊標
可以通過where current of cursor_name 來進行定位
declare OrderHeaderCursor scroll cursor
for
select SalesOrderID, OrderDate,SubTotal
from Sales.SalesOrderHeader
where SalesOrderID > 75118
order by SalesOrderID
for update
open OrderHeaderCursor
fetch first from OrderHeaderCursor
update Sales.SalesOrderHeader
set SubTotal = 189.96
where current of OrderHeaderCursor
close OrderHeaderCursor
deallocate OrderHeaderCursor(3) 滾動遊標
在cursor前加上關鍵字scroll,就可以出創建滾動遊標了,
對於fetch語句,除了next外,還可以使用其他
FETCH [ [ NEXT | PRIOR | FIRST | LAST | ABSOLUTE { n | @nvar } | RELATIVE { n | @nvar } ] FROM ] { { [ GLOBAL ] cursor_name } | @cursor_variable_name } [ INTO @variable_name [ ,...n ] ]NEXT
Returns the result row immediately following the current row and increments the current row to the row returned. If FETCH NEXT is the first fetch against a cursor, it returns the first row in the result set. NEXT is the default cursor fetch option.
PRIORReturns the result row immediately preceding the current row, and decrements the current row to the row returned. If FETCH PRIOR is the first fetch against a cursor, no row is returned and the cursor is left positioned before the first row.
FIRSTReturns the first row in the cursor and makes it the current row.
LASTReturns the last row in the cursor and makes it the current row.
ABSOLUTE { n | @nvar}If n or @nvar is positive, returns the row n rows from the front of the cursor and makes the returned row the new current row. If n or @nvaris negative, returns the row n rows before the end of the cursor and makes the returned row the new current row. If n or @nvar is 0, no rows are returned. n must be an integer constant and @nvar must be smallint, tinyint, or int.
RELATIVE { n | @nvar}If n or @nvar is positive, returns the row n rows beyond the current row and makes the returned row the new current row. If n or @nvar is negative, returns the row n rows prior to the current row and makes the returned row the new current row. If n or @nvar is 0, returns the current row. If FETCH RELATIVE is specified with n or @nvar set to negative numbers or 0 on the first fetch done against a cursor, no rows are returned. n must be an integer constant and @nvar must be smallint, tinyint, or int.
GLOBALSpecifies that cursor_name refers to a global cursor.
cursor_nameIs the name of the open cursor from which the fetch should be made. If both a global and a local cursor exist with cursor_name as their name, cursor_name to the global cursor if GLOBAL is specified and to the local cursor if GLOBAL is not specified.
@cursor_variable_nameIs the name of a cursor variable referencing the open cursor from which the fetch should be made.
INTO @variable_name[ ,...n]Allows data from the columns of a fetch to be placed into local variables. Each variable in the list, from left to right, is associated with the corresponding column in the cursor result set. The data type of each variable must either match or be a supported implicit conversion of the data type of the corresponding result set column. The number of variables must match the number of columns in the cursor select list.
(4)聲明遊標變量