sql中的觸發器是對某個表進行操作時而觸發的某種條件,可以用CREATE語句建立觸發器,DROP語句刪除觸發器,ALTER語句停用觸發器等
觸發器
在SQL Server裡面也就是對某一個表的一定的操作,觸發某種條件,從而執行的一段程式。觸發器是一個特殊的預存程序。
CREATE TRIGGER tr_update_Stock --自动采购触发器 ON T_Product FOR update AS IF (update(Stock)) --判断stock字段是否更新 BEGIN --查询出库存低于下限的产品近一个月的消耗量 --创建临时表 IF object_id('[tempdb].[dbo].##table1') IS NOT NULL --判断临时表#tmp是否存在,存在则删除 DROP TABLE ##table1 SELECT * INTO ##table1 FROM (SELECT row_number() OVER (ORDER BY ProductID) AS rowNo,c.ZNumber - c.Stock AS purchaseNum,* FROM ( SELECT ProductID,SUM(s.Numbers) ZNumber,p.Stock,SUM(s.OutMoney) ZMoney,p.Price FROM [dbo].[T_StorageOut] t inner join[dbo].[T_StorageRelation] s ON t.StorageOutID=s.StorageOutID inner join T_Product p ON s.ProductID=p.Id WHERE t.MakerTime between Convert(VARCHAR,DATEADD(MONTH,-1,GETDATE()),23) and Convert(VARCHAR,GETDATE(),23) and ProductID in (SELECT Id FROM V_ProductSupplierInfo where (Stock-StockLowerLimit)<0) GROUP BY ProductID,p.Stock,p.Price) c) ddd --计算用参数 DECLARE @purchaseNum INT,@Price NVARCHAR(50),@totalMoney NVARCHAR(50),@ZpurchaseTotal INT --采购数量,单价,总金额,总数量 SELECT @totalMoney = 0,@purchaseNum = 0,@Price = 0,@ZpurchaseTotal=0 --采购单所需参数 DECLARE @PurchaseNumber NVARCHAR(50),@DopurchaseId INT,@DopurchaseTime NVARCHAR(200),@PurchaseTotal INT,@PurchasePrice NVARCHAR(200),@PurchaseState INT,@PurchaseType INT SET @PurchaseNumber='JH'+replace(replace(replace(convert(VARCHAR,getdate(),120),'-',''),' ',''),':','') --进货单号JH20171031092322 --采购单详情所需参数 (产品id,产品采购价格) DECLARE @StockProductId INT,@DPurchasePrice NVARCHAR(20) --循环用参数 DECLARE @curIndex INT,@rowCount INT --判断用参数 DECLARE @OTCount INT,@PTCount INT SET @curIndex = 1 SELECT @rowCount = COUNT(1) FROM ##table1 IF(@rowCount>0) BEGIN WHILE @curIndex <= @rowCount BEGIN --查询出第一行数据的采购数量,单价,产品id SELECT @purchaseNum = purchaseNum,@Price = Price,@StockProductId =ProductID FROM ##table1 WHERE rowNo = @curIndex --采购总金额 SET @totalMoney = @totalMoney + @purchaseNum * CONVERT (INT,@price) --采购总数量 SET @ZpurchaseTotal =@ZpurchaseTotal + @purchaseNum --单个产品的采购金额 SET @DPurchasePrice=@purchaseNum * CONVERT (INT,@price) IF object_id('[tempdb].[dbo].#PTable') IS NOT NULL --判断临时表#tmp是否存在,存在则删除 DROP TABLE #PTable IF object_id('[tempdb].[dbo].#OTable') IS NOT NULL --判断临时表#tmp是否存在,存在则删除 DROP TABLE #OTable --根据产品id查询出包含该产品的采购单已全部审批 SELECT * INTO #PTable FROM (SELECT PurchaseState FROM [dbo].[T_Purchase_Order] WHERE PurchaseNumber in(SELECT PurchaseOrderId FROM [dbo].[T_Purchase_OrderDetails] WHERE StockProductId=@StockProductId) and PurchaseState=0) AS a --根据产品id查询出包含该产品的订单已全部入库 SELECT * INTO #OTable FROM (SELECT OrderState FROM T_Order WHERE OrderNumber in(SELECT OrderNumber FROM T_OrderDetails WHERE ProductId=@StockProductId) and OrderState=0) AS c SELECT @PTCount = COUNT(1) FROM #PTable SELECT @OTCount = COUNT(1) FROM #OTable IF (@PTCount=0) --已全部审批 BEGIN IF(@OTCount=0) --=0表示包含该产品的订单均已入库,可以生成新的 BEGIN INSERT INTO [dbo].[T_Purchase_OrderDetails] VALUES(@PurchaseNumber,@StockProductId,@purchaseNum,@DPurchasePrice) END END SET @curIndex = @curIndex + 1 END END set @DopurchaseId = 16646 --自动生成 set @DopurchaseTime=Convert(NVARCHAR,getdate(),23) --当前时间 2017-10-31 set @PurchaseTotal =@ZpurchaseTotal set @PurchasePrice =@totalMoney set @PurchaseState =0 --未审核 set @PurchaseType = 2 --自动生成 --变量赋值完成,对采购单做添加操作 IF (@PTCount=0) BEGIN INSERT INTO T_Purchase_Order VALUES(@PurchaseNumber,@DopurchaseId,@DopurchaseTime,@PurchaseTotal,@PurchasePrice,@PurchaseState,@PurchaseType) END END
這是一個自動採購的觸發器,主要需要注意的觸發條件,以及臨時表的作用。
觸發器的使用
建立觸發器
CREATE TRIGGER tr_update_Stock
刪除觸發器
DROP TRIGGER tr_update_Stock
停用
ALTER TABLE trig_example DISABLE TRIGGER trig1 GO
恢復
#ALTER TABLE trig_example ENABLE TRIGGER trig1 GO
停用某個表上的所有觸發器
#ALTER TABLE 你的表 DISABLE TRIGGER all
啟用某個表上的所有觸發器
ALTER TABLE 你的表 enable TRIGGER all
#停用所有表上的所有觸發器
exec sp_msforeachtable 'ALTER TABLE ? DISABLE TRIGGER all'
exec sp_msforeachtable 'ALTER TABLE ? enable TRIGGER all'
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