SQL SERVER - Data Cursors

Artigo original:
https://msdn.microsoft.com/en-us/library/ms180169.aspx

Exemplo:

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;