Question

我想将Customer表中发生的更改保存到SQL Server 2008中的另一个表Notification中。为此，我编写了以下触发器：

CREATE TRIGGER [CustomerNotifier]
                         ON [dbo].[Customer]
                         AFTER INSERT, UPDATE, DELETE
                         AS
                         BEGIN
                            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)

                            IF @Action = 'I'
                            BEGIN
                                INSERT INTO Notification (CustomerId, BookingId, [Type], [Read], TenantId, TenantUsername, CreatedDateTime)
                                SELECT CustomerId, null, 0, 0, TenantId, AspNetUsers.UserName, CURRENT_TIMESTAMP FROM inserted
                                JOIN AspNetUsers ON  inserted.TenantId = AspNetUsers.Id;
                            END
                            ELSE IF @Action = 'U'
                            BEGIN
                                INSERT INTO Notification (CustomerId, BookingId, [Type], [Read], TenantId, TenantUsername, CreatedDateTime)
                                SELECT CustomerId, null, 1, 0, TenantId, AspNetUsers.UserName, CURRENT_TIMESTAMP FROM inserted
                                JOIN AspNetUsers ON  inserted.TenantId = AspNetUsers.Id;
                            END
                            ELSE IF @Action = 'D'
                            BEGIN
                                INSERT INTO Notification (CustomerId, BookingId, [Type], [Read], TenantId, TenantUsername, CreatedDateTime)
                                SELECT CustomerId, null, 1, 0, TenantId, AspNetUsers.UserName, CURRENT_TIMESTAMP FROM deleted
                                JOIN AspNetUsers ON  deleted.TenantId = AspNetUsers.Id;
                            END
                         END

当客户表格中的客户已插入或已删除时触发器成功执行，但触发器未在更新时执行。

我可能知道原因：它没有执行，因为我们正在更新另一个表AspNetUsers中的条目，该表通过共享主键关系与Customer表链接。

所以我的问题是如何在Update ??

上执行此触发器

Answer 1

只有在定义了触发器的表上存在相应的DML时，触发器才会触发。

要在此处执行触发器，您应该在AspNetUsers表上创建实际更新的触发器，或者更新Customer表。请记住，inserted和deleted伪表将包含定义触发器的表的数据。

在Update上没有触发Sql触发器，为什么

1 个答案: