如何使用sql游標更新sql server數據庫中的數據？

Question

我正在嘗試開發一個庫存管理系統。 但是問題是當我要在庫存表中庫存時，這些產品數量需要一次在項目表中更新。 例如，當我按下保存按鈕時，我要增加庫存表中100種產品的庫存，其中所有狀態為'Posting'的產品將根據項目代碼更新為tbl_item.quantity + tbl_stock.qty 。 請幫我...

這是我要增加庫存的桌子。

CREATE TABLE [dbo].[tbl_Addstock](
    [id] [int] IDENTITY(1,1) NOT NULL,
    [ItemCode] [varchar](50) NOT NULL,
    [ItemName] [varchar](250) NOT NULL,
    [qty] [decimal](18, 2) NOT NULL,
    [sdate] [date] NOT NULL,
    [sadmin] [varchar](50) NOT NULL,
    [Status] [varchar](50) NULL,
 CONSTRAINT [PK_tbl_Addstock] PRIMARY KEY CLUSTERED 
(
    [id] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY] 

這是我要更新我的總庫存信息的另一個項目表。

CREATE TABLE [dbo].[tbl_Item](
    [id] [int] IDENTITY(1,1) NOT NULL,
    [name] [nvarchar](50) NOT NULL,
    [batchno] [nvarchar](50) NOT NULL,
    [brand] [nvarchar](50) NOT NULL,
    [itemcode] [varchar](50) NOT NULL,
    [catg] [nvarchar](50) NOT NULL,
    [supplier] [nvarchar](50) NULL,
    [unitType] [nvarchar](50) NOT NULL,
    [Quantity] [decimal](18, 2) NULL,
    [buyingPrice] [money] NULL,
    [sellingPrice] [money] NULL,
    [qtyLimit] [int] NULL,
    [vat] [decimal](18, 2) NULL,
 CONSTRAINT [PK_tbl_Item] PRIMARY KEY CLUSTERED 
(
    [id] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY] 

然后我嘗試了一個游標查詢。

USE [NMCPMC]
GO
/****** Object:  StoredProcedure [dbo].[sp_UpdateItem]    Script Date: 01/07/2015 12:41:48 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
--exec sp_UpdateItem
ALTER PROCEDURE [dbo].[sp_UpdateItem] 
AS
BEGIN
SET NOCOUNT ON
DECLARE 
    @TEMP                        AS VARCHAR(50), @ItemCode varchar(20),
    @eqty decimal(18,2)

DECLARE ITEM_CURSOR CURSOR FOR
SELECT ItemCode,qty FROM tbl_Addstock 
OPEN ITEM_CURSOR
    FETCH NEXT FROM ITEM_CURSOR
INTO @ItemCode,@TEMP

WHILE (@@FETCH_STATUS = 0)
BEGIN
    --set @eqty = (select Quantity from tbl_Item)
 --   SELECT @TEMP = SUM(ti.Quantity+ta.qty) from tbl_Addstock ta inner join tbl_Item ti on ta.ItemCode=ti.itemcode
 --   UPDATE tbl_Item SET Quantity = @TEMP WHERE CURRENT OF ITEM_CURSOR
 if exists(select * from tbl_Addstock where ItemCode=@ItemCode)
  begin 
   UPDATE tbl_Addstock SET qty = qty+@TEMP WHERE ItemCode=@ItemCode
   update tbl_Addstock set qty=qty-@TEMP WHERE ItemCode=@ItemCode
  end
  else
  begin
--  insert into tbl_Addstock
  update tbl_Addstock set qty=qty-@TEMP WHERE ItemCode=@ItemCode 
  end
    print @ItemCode
    print @TEMP
    FETCH NEXT FROM ITEM_CURSOR
    INTO @ItemCode,@TEMP
END

CLOSE ITEM_CURSOR
DEALLOCATE ITEM_CURSOR

SET NOCOUNT OFF
END
--EXEC sp_UpdateItem 

Answer 1

因此，您想將tbl_AddStock中表示的數量添加到tbl_Item中。 您的SP似乎無法正常工作，因為您從未觸摸過表tbl_Item的數量字段。

我會寫

ALTER PROCEDURE [dbo].[sp_UpdateItem] 
AS
BEGIN
SET NOCOUNT ON
DECLARE 
    @ItemCode varchar(20),
    @eqty decimal(18,2)

DECLARE ITEM_CURSOR CURSOR FOR
SELECT ItemCode,qty FROM tbl_Addstock WHERE Status = 'Posting'
OPEN ITEM_CURSOR
FETCH NEXT FROM ITEM_CURSOR
INTO @ItemCode,@eqty

WHILE (@@FETCH_STATUS = 0)
BEGIN
if exists(select * from tbl_Item where ItemCode=@ItemCode)
  begin 
   UPDATE tbl_Item     SET quantity = quantity + @eqty WHERE ItemCode=@ItemCode
   UPDATE tbl_Addstock SET qty = qty - @eqty, Status = 'Posted' WHERE ItemCode=@ItemCode
   -- COULD AVOID THE MATH. SIMPLY SET QTY=0
   -- ? UPDATE tbl_Addstock SET qty      = 0           WHERE ItemCode=@ItemCode
  end
else
  begin
   -- THIS ELSE PART IS WHERE YOU DISCOVER THAT tbl_Item 
   -- HAD NO RECORD FOR THE @ItemCode.
   -- YOU SHOULD ADD THE NEW ITEM TO THE tblItem TABLE
   -- BUT MANY FIELDS OF THAT TABLE ARE NOT NULL (batchno, catg, brand, unittype)
   -- SO YOU NEED TO KNOW THE VALUES FOR THESE
   -- FIELDS OTHERWISE YOU WONT BE ABLE TO ADD ANYTHING 
   -- ??? -> INSERT INTO tbl_Item(ItemCode, Qty) VALUES (@itemcode, @eqty)
  end
  FETCH NEXT FROM ITEM_CURSOR
  INTO @ItemCode,@qty
END
CLOSE ITEM_CURSOR
DEALLOCATE ITEM_CURSOR

SET NOCOUNT OFF
END