插入更新触发器如何确定是否插入或更新

我需要在表A上编写一个Insert，Update Trigger，它将从表B中删除表B中所有行，其中一列（称为Desc）具有类似于表A的列（比如Col1）中插入/更新的值。 我将如何去写它，以便我可以处理更新和插入案例。 我将如何确定触发器是否执行更新或插入。

Answer 1

如果是MS SQL Server …

触发器有特殊的INSERTED和DELETED表来跟踪“之前”和“之后”的数据。 所以你可以使用像IF EXISTS (SELECT * FROM DELETED)来检测更新。 在更新时只有DELETED行，但在INSERTED中总是有行。

在CREATE TRIGGER中查找“插入”

编辑，2011年11月23日

评论之后，这个答案只适用于INSERTED和UPDATED触发器。
显然，如上所述，DELETE触发器不能“在INSERTED总是行”

Answer 2

 CREATE TRIGGER dbo.TableName_IUD ON dbo.TableName AFTER INSERT, UPDATE, DELETE AS BEGIN SET NOCOUNT ON; -- -- Check if this is an INSERT, UPDATE or DELETE Action. -- DECLARE @action as char(1); SET @action = 'I'; -- Set Action to Insert by default. IF EXISTS(SELECT * FROM DELETED) BEGIN SET @action = CASE WHEN EXISTS(SELECT * FROM INSERTED) THEN 'U' -- Set Action to Updated. ELSE 'D' -- Set Action to Deleted. END END ELSE IF NOT EXISTS(SELECT * FROM INSERTED) RETURN; -- Nothing updated or inserted. ... END 

Answer 3

如果您运行删除语句不删除任何内容，其中许多build议不会考虑在内。
假设您尝试删除ID等于表中不存在的某个值的位置。
您的触发器仍然被调用，但是在已删除或已插入的表中没有任何内容。

使用这个是安全的：

 --Determine if this is an INSERT,UPDATE, or DELETE Action or a "failed delete". DECLARE @Action as char(1); SET @Action = (CASE WHEN EXISTS(SELECT * FROM INSERTED) AND EXISTS(SELECT * FROM DELETED) THEN 'U' -- Set Action to Updated. WHEN EXISTS(SELECT * FROM INSERTED) THEN 'I' -- Set Action to Insert. WHEN EXISTS(SELECT * FROM DELETED) THEN 'D' -- Set Action to Deleted. ELSE NULL -- Skip. It may have been a "failed delete". END) 

特别感谢@KenDog和@Net_Prog的答案。
我从他们的脚本build立这个。

Answer 4

我正在使用以下，它也正确地检测删除语句，删除任何东西：

 CREATE TRIGGER dbo.TR_TableName_TriggerName ON dbo.TableName AFTER INSERT, UPDATE, DELETE AS BEGIN SET NOCOUNT ON; IF NOT EXISTS(SELECT * FROM INSERTED) -- DELETE PRINT 'DELETE'; ELSE BEGIN IF NOT EXISTS(SELECT * FROM DELETED) -- INSERT PRINT 'INSERT'; ELSE -- UPDATE PRINT 'UPDATE'; END END; 

Answer 5

经过大量的search，我找不到一个SQL Server触发器的确切例子，它可以处理触发器动作INSERT，UPDATE和DELETE的所有（3）三个条件。 我终于find了一段文字，谈到DELETE或UPDATE发生时，常见的DELETED表将包含这两个动作的logging。 基于这些信息，我创build了一个小的Action例程，它决定了触发器被激活的原因。 当在INSERT和UPDATE触发器上同时存在通用configuration和特定操作时，有时需要这种types的接口。 在这些情况下，为UPDATE创build单独的触发器，INSERT将成为维护问题。 （即两个触发器正确更新为必要的常见数据algorithm修复？）

为此，我想给出以下多触发事件代码片段，用于在Microsoft SQL Server的一个触发器中处理INSERT，UPDATE，DELETE。

 CREATE TRIGGER [dbo].[INSUPDDEL_MyDataTable] ON [dbo].[MyDataTable] FOR INSERT, UPDATE, DELETE AS -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with caller queries SELECT statements. -- If an update/insert/delete occurs on the main table, the number of records affected -- should only be based on that table and not what records the triggers may/may not -- select. SET NOCOUNT ON; -- -- Variables Needed for this Trigger -- DECLARE @PACKLIST_ID varchar(15) DECLARE @LINE_NO smallint DECLARE @SHIPPED_QTY decimal(14,4) DECLARE @CUST_ORDER_ID varchar(15) -- -- Determine if this is an INSERT,UPDATE, or DELETE Action -- DECLARE @Action as char(1) DECLARE @Count as int SET @Action = 'I' -- Set Action to 'I'nsert by default. SELECT @Count = COUNT(*) FROM DELETED if @Count > 0 BEGIN SET @Action = 'D' -- Set Action to 'D'eleted. SELECT @Count = COUNT(*) FROM INSERTED IF @Count > 0 SET @Action = 'U' -- Set Action to 'U'pdated. END if @Action = 'D' -- This is a DELETE Record Action -- BEGIN SELECT @PACKLIST_ID =[PACKLIST_ID] ,@LINE_NO = [LINE_NO] FROM DELETED DELETE [dbo].[MyDataTable] WHERE [PACKLIST_ID]=@PACKLIST_ID AND [LINE_NO]=@LINE_NO END Else BEGIN -- -- Table INSERTED is common to both the INSERT, UPDATE trigger -- SELECT @PACKLIST_ID =[PACKLIST_ID] ,@LINE_NO = [LINE_NO] ,@SHIPPED_QTY =[SHIPPED_QTY] ,@CUST_ORDER_ID = [CUST_ORDER_ID] FROM INSERTED if @Action = 'I' -- This is an Insert Record Action -- BEGIN INSERT INTO [MyChildTable] (([PACKLIST_ID] ,[LINE_NO] ,[STATUS] VALUES (@PACKLIST_ID ,@LINE_NO ,'New Record' ) END else -- This is an Update Record Action -- BEGIN UPDATE [MyChildTable] SET [PACKLIST_ID] = @PACKLIST_ID ,[LINE_NO] = @LINE_NO ,[STATUS]='Update Record' WHERE [PACKLIST_ID]=@PACKLIST_ID AND [LINE_NO]=@LINE_NO END END 

Answer 6

我相信嵌套如果有点混乱，并且：

平面比嵌套更好[Python的禅]

;）

 DROP TRIGGER IF EXISTS AFTER_MYTABLE GO CREATE TRIGGER dbo.AFTER_MYTABLE ON dbo.MYTABLE AFTER INSERT, UPDATE, DELETE AS BEGIN --- FILL THE BEGIN/END SECTION FOR YOUR NEEDS. SET NOCOUNT ON; IF EXISTS(SELECT * FROM INSERTED) AND EXISTS(SELECT * FROM DELETED) BEGIN PRINT 'UPDATE' END ELSE IF EXISTS(SELECT * FROM INSERTED) AND NOT EXISTS(SELECT * FROM DELETED) BEGIN PRINT 'INSERT' END ELSE IF EXISTS(SELECT * FROM DELETED) AND NOT EXISTS(SELECT * FROM INSERTED) BEGIN PRINT 'DELETED' END ELSE BEGIN PRINT 'NOTHING CHANGED'; RETURN; END -- NOTHING END 

Answer 7

尝试这个..

 ALTER TRIGGER ImportacionesGS ON dbo.Compra AFTER INSERT, UPDATE, DELETE AS BEGIN -- idCompra is PK DECLARE @vIdCompra_Ins INT,@vIdCompra_Del INT SELECT @vIdCompra_Ins=Inserted.idCompra FROM Inserted SELECT @vIdCompra_Del=Deleted.idCompra FROM Deleted IF (@vIdCompra_Ins IS NOT NULL AND @vIdCompra_Del IS NULL) Begin -- Todo Insert End IF (@vIdCompra_Ins IS NOT NULL AND @vIdCompra_Del IS NOT NULL) Begin -- Todo Update End IF (@vIdCompra_Ins IS NULL AND @vIdCompra_Del IS NOT NULL) Begin -- Todo Delete End END 

Answer 8

 Declare @Type varchar(50)=''; IF EXISTS (SELECT * FROM inserted) and EXISTS (SELECT * FROM deleted) BEGIN SELECT @Type = 'UPDATE' END ELSE IF EXISTS(SELECT * FROM inserted) BEGIN SELECT @Type = 'INSERT' END ElSE IF EXISTS(SELECT * FROM deleted) BEGIN SELECT @Type = 'DELETE' END 

Answer 9

提供的两个解决scheme的潜在问题是，根据它们的写法，更新查询可能会更新零个logging，插入查询可能会插入零个logging。 在这些情况下，插入和删除logging集将是空的。 在许多情况下，如果“插入”和“已删除”logging集都为空，则可能只是想不做任何事情而退出触​​发器。

Answer 10

这可能是一个更快的方法：

 DECLARE @action char(1) IF COLUMNS_UPDATED() > 0 -- insert or update BEGIN IF EXISTS (SELECT * FROM DELETED) -- update SET @action = 'U' ELSE SET @action = 'I' END ELSE -- delete SET @action = 'D' 

Answer 11

我喜欢“计算机科学优雅”的解决scheme。 我的解决scheme在这里每次触发[插入]和[删除]伪指令来获得它们的状态，并把结果放在一个位映射variables中。 然后，可以通过有效的二进制评估（除了不太可能的INSERT或DELETE组合）在INSERT，UPDATE和DELETE的各个可能组合之间轻松地对整个触发器进行testing。

它确实假定，如果没有行被修改（这应该满足绝大多数情况），DML语句是什么并不重要。 所以虽然没有罗马派克的解决scheme那么完整，但效率更高。

通过这种方法，我们有可能为每个表创build一个“FOR INSERT，UPDATE，DELETE”触发器，给我们A）完全控制动作顺序和b）每个多行为适用动作的一个代码实现。 （很明显，每个实现模型都有其优缺点，您需要分别评估您的系统是否真正有效。

请注意，“exists（select * from«inserted / deleted»）”语句是非常有效的，因为没有磁盘访问（ https://social.msdn.microsoft.com/Forums/en-US/01744422-23fe-42f6 -9ab0-a255cdf2904a ）。

 use tempdb ; create table dbo.TrigAction (asdf int) ; GO create trigger dbo.TrigActionTrig on dbo.TrigAction for INSERT, UPDATE, DELETE as declare @Action tinyint ; -- Create bit map in @Action using bitwise OR "|" set @Action = (-- 1: INSERT, 2: DELETE, 3: UPDATE, 0: No Rows Modified (select case when exists (select * from inserted) then 1 else 0 end) | (select case when exists (select * from deleted ) then 2 else 0 end)) ; -- 21 <- Binary bit values -- 00 -> No Rows Modified -- 01 -> INSERT -- INSERT and UPDATE have the 1 bit set -- 11 -> UPDATE < -- 10 -> DELETE -- DELETE and UPDATE have the 2 bit set raiserror(N'@Action = %d', 10, 1, @Action) with nowait ; if (@Action = 0) raiserror(N'No Data Modified.', 10, 1) with nowait ; -- do things for INSERT only if (@Action = 1) raiserror(N'Only for INSERT.', 10, 1) with nowait ; -- do things for UPDATE only if (@Action = 3) raiserror(N'Only for UPDATE.', 10, 1) with nowait ; -- do things for DELETE only if (@Action = 2) raiserror(N'Only for DELETE.', 10, 1) with nowait ; -- do things for INSERT or UPDATE if (@Action & 1 = 1) raiserror(N'For INSERT or UPDATE.', 10, 1) with nowait ; -- do things for UPDATE or DELETE if (@Action & 2 = 2) raiserror(N'For UPDATE or DELETE.', 10, 1) with nowait ; -- do things for INSERT or DELETE (unlikely) if (@Action in (1,2)) raiserror(N'For INSERT or DELETE.', 10, 1) with nowait -- if already "return" on @Action = 0, then use @Action < 3 for INSERT or DELETE ; GO set nocount on; raiserror(N' INSERT 0...', 10, 1) with nowait; insert dbo.TrigAction (asdf) select top 0 object_id from sys.objects; raiserror(N' INSERT 3...', 10, 1) with nowait; insert dbo.TrigAction (asdf) select top 3 object_id from sys.objects; raiserror(N' UPDATE 0...', 10, 1) with nowait; update t set asdf = asdf /1 from dbo.TrigAction t where asdf <> asdf; raiserror(N' UPDATE 3...', 10, 1) with nowait; update t set asdf = asdf /1 from dbo.TrigAction t; raiserror(N' DELETE 0...', 10, 1) with nowait; delete t from dbo.TrigAction t where asdf < 0; raiserror(N' DELETE 3...', 10, 1) with nowait; delete t from dbo.TrigAction t; GO drop table dbo.TrigAction ; GO 

Answer 12

我在Grahams中发现了一个小错误，否则很酷的解决scheme：

它应该是IF COLUMNS_UPDATED（） < > 0 – 插入或更新
而不是> 0，可能是因为最高位被解释为SIGNED整数符号位…（？）。 所以总的来说：

 DECLARE @action CHAR(8) IF COLUMNS_UPDATED() <> 0 -- delete or update? BEGIN IF EXISTS (SELECT * FROM deleted) -- updated cols + old rows means action=update SET @action = 'UPDATE' ELSE SET @action = 'INSERT' -- updated columns and nothing deleted means action=insert END ELSE -- delete BEGIN SET @action = 'DELETE' END 

Answer 13

快速解决MySQL

顺便说一下：我正在使用MySQL PDO。

（1）在自动增量表中，每个脚本首先运行一次，从递增的列中获取最高值（我的列名= id）：

 $select = " SELECT MAX(id) AS maxid FROM [tablename] LIMIT 1 "; 

（2）像你一样运行MySQL查询，并将结果转换为整数，例如：

 $iMaxId = (int) $result[0]->maxid; 

（3）在“INSERT INTO … ON DUPLICATE KEY UPDATE”查询后，以最佳方式获取最后插入的ID，例如：

 $iLastInsertId = (int) $db->lastInsertId(); 

（4）比较和反应：如果lastInsertId高于表中的最高值，那么可能是INSERT，对吧？ 反之亦然。

 if ($iLastInsertId > $iMaxObjektId) { // IT'S AN INSERT } else { // IT'S AN UPDATE } 

我知道这很快，也许很脏。 这是一个旧的职位。 但是，嘿，我正在寻找一个很长时间的解决scheme，也许有人觉得我的方式有点有用。 祝一切顺利！

Answer 14

这对我来说是个窍门：

 declare @action_type int; select @action_type = case when i.id is not null and d.id is null then 1 -- insert when i.id is not null and d.id is not null then 2 -- update when i.id is null and d.id is not null then 3 -- delete end from inserted i full join deleted d on d.id = i.id 

由于并不是所有的列都可以一次更新，所以你可以通过类似这样的方式来检查一个特定的列是否被更新：

 IF UPDATE([column_name]) 

Answer 15

只是简单的方法

 CREATE TRIGGER [dbo].[WO_EXECUTION_TRIU_RECORD] ON [dbo].[WO_EXECUTION] WITH EXECUTE AS CALLER FOR INSERT, UPDATE AS BEGIN select @vars = [column] from inserted IF UPDATE([column]) BEGIN -- do update action base on @vars END ELSE BEGIN -- do insert action base on @vars END END 

Answer 16

 declare @insCount int declare @delCount int declare @action char(1) select @insCount = count(*) from INSERTED select @delCount = count(*) from DELETED if(@insCount > 0 or @delCount > 0)--if something was actually affected, otherwise do nothing Begin if(@insCount = @delCount) set @action = 'U'--is update else if(@insCount > 0) set @action = 'I' --is insert else set @action = 'D' --is delete --do stuff here End 

Answer 17

在第一种情况下，我认为你的表有IDENTITY列

 CREATE TRIGGER [dbo].[insupddel_yourTable] ON [yourTable] FOR INSERT, UPDATE, DELETE AS IF @@ROWCOUNT = 0 return SET NOCOUNT ON; DECLARE @action nvarchar(10) SELECT @action = CASE WHEN COUNT(i.Id) > COUNT(d.Id) THEN 'inserted' WHEN COUNT(i.Id) < COUNT(d.Id) THEN 'deleted' ELSE 'updated' END FROM inserted i FULL JOIN deleted d ON i.Id = d.Id 

在第二种情况下不需要使用IDENTITTY列

 CREATE TRIGGER [dbo].[insupddel_yourTable] ON [yourTable] FOR INSERT, UPDATE, DELETE AS IF @@ROWCOUNT = 0 return SET NOCOUNT ON; DECLARE @action nvarchar(10), @insCount int = (SELECT COUNT(*) FROM inserted), @delCount int = (SELECT COUNT(*) FROM deleted) SELECT @action = CASE WHEN @insCount > @delCount THEN 'inserted' WHEN @insCount < @delCount THEN 'deleted' ELSE 'updated' END 

Answer 18

 DECLARE @INSERTEDCOUNT INT, @DELETEDCOUNT INT SELECT @INSERTEDCOUNT = COUNT([YourColumnName]) FROM inserted SELECT @DELETEDCOUNT = COUNT([YourColumnName]) FROM deleted 

如果它的更新

  @INSERTEDCOUNT = 1 @DELETEDCOUNT = 1 

如果插入

  @INSERTEDCOUNT = 1 @DELETEDCOUNT = 0 

Answer 19

我已经使用这些exists (select * from inserted/deleted)查询很长一段时间，但它仍然是不够的空CRUD操作（当inserted和deleted表中没有logging）。 所以在研究了这个话题之后，我发现了更精确的解决scheme：

 declare @columns_count int = ?? -- number of columns in the table, @columns_updated_count int = 0 -- this is kind of long way to get number of actually updated columns -- from columns_updated() mask, it's better to create helper table -- or at least function in the real system with cte_columns as ( select @columns_count as n union all select n - 1 from cte_columns where n > 1 ), cte_bitmasks as ( select n, (n - 1) / 8 + 1 as byte_number, power(2, (n - 1) % 8) as bit_mask from cte_columns ) select @columns_updated_count = count(*) from cte_bitmasks as c where convert(varbinary(1), substring(@columns_updated_mask, c.byte_number, 1)) & c.bit_mask > 0 -- actual check if exists (select * from inserted) if exists (select * from deleted) select @operation = 'U' else select @operation = 'I' else if exists (select * from deleted) select @operation = 'D' else if @columns_updated_count = @columns_count select @operation = 'I' else if @columns_updated_count > 0 select @operation = 'U' else select @operation = 'D' 

也可以使用columns_updated() & power(2, column_id - 1) > 0来查看列是否更新，但对于列数很大的表是不安全的。 我用了一些复杂的计算方法（请参阅下面的帮助文章）。

此外，这种方法仍然会错误地将某些更新分类为插入（如果表中的每一列都受到更新的影响），并且可能会对只插入默认值的插入进行分类，但这些操作是罕见操作之王在我的系统租赁他们）。 除此之外，目前我不知道如何改进这个解决scheme。

• 对于Piotr Rodak的审计触发器，COLUMNS_UPDATED（）
• Adam Machanic处理非常大的位掩码