批量update代替游标
今天写了一个SQL,觉得挺牛逼的,被人一句话 毙了
DECLARE @ProductId INT , @ProductCount INT --提仓调整冻结库存 IF @Adjusttype=1 BEGIN DECLARE orderDetail_CURSOR CURSOR FOR SELECT ProductId,ProductCount FROM dbo.OrderDetail WITH(NOLOCK) WHERE OrderID= @OrderID OPEN orderDetail_CURSOR FETCH NEXT FROM orderDetail_CURSOR INTO @ProductId,@ProductCount WHILE @@FETCH_STATUS = 0 BEGIN --改商品冻结库存 (原订单仓库) UPDATE dbo.InventoryForEdit SET FrozenStock = FrozenStock - @ProductCount WHERE ItemId = @ProductId AND ItemType = 1 and WarehouseId = @OriginalWarehouseID --改商品冻结库存 (换选仓后的仓库) UPDATE dbo.InventoryForEdit SET FrozenStock = FrozenStock + @ProductCount WHERE ItemId = @ProductId AND ItemType = 1 and WarehouseId = @WarehouseId FETCH NEXT FROM orderDetail_CURSOR INTO @ProductId,@ProductCount END CLOSE orderDetail_CURSOR DEALLOCATE orderDetail_CURSOR END ELSE --提仓失败 回滚数据 BEGIN DECLARE orderDetail_CURSOR CURSOR FOR SELECT ProductId,ProductCount FROM dbo.OrderDetail WITH(NOLOCK) WHERE OrderID=@OrderID OPEN orderDetail_CURSOR FETCH NEXT FROM orderDetail_CURSOR INTO @ProductId,@ProductCount WHILE @@FETCH_STATUS = 0 BEGIN --改商品冻结库存 (原订单仓库) UPDATE dbo.InventoryForEdit SET FrozenStock = FrozenStock + @ProductCount WHERE ItemId = @ProductId AND ItemType = 1 and WarehouseId = @OriginalWarehouseID --改商品冻结库存 (换选仓后的仓库) UPDATE dbo.InventoryForEdit SET FrozenStock = FrozenStock - @ProductCount WHERE ItemId = @ProductId AND ItemType = 1 and WarehouseId = @WarehouseId FETCH NEXT FROM orderDetail_CURSOR INTO @ProductId,@ProductCount END CLOSE orderDetail_CURSOR DEALLOCATE orderDetail_CURSOR END
下面是更改后的SQL,而且参数,传的更少了。执行效率更高了,道行还是浅啊。
--改商品冻结库存 (原订单仓库) UPDATE InventoryForEdit SET InventoryForEdit.FrozenStock=InventoryForEdit.FrozenStock - O.ProductCount FROM OrderDetail AS O WITH(NOLOCK) WHERE InventoryForEdit.ItemId=O.ProductId AND InventoryForEdit.ItemType=O.ItemType AND InventoryForEdit.WarehouseId=@OriginalWarehouseID AND O.OrderID=@OrderID --改商品冻结库存 (换选仓后的仓库) UPDATE InventoryForEdit SET InventoryForEdit.FrozenStock=InventoryForEdit.FrozenStock +O.ProductCount FROM OrderDetail AS O WITH(NOLOCK) WHERE InventoryForEdit.ItemId=O.ProductId AND InventoryForEdit.ItemType=O.ItemType AND InventoryForEdit.WarehouseId=@WarehouseId AND O.OrderID=@OrderID
觉得自己很牛逼的SQL ,被老大一句话干掉了,应该问他怎么想到的