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This article mainly explains "how SqlServer implements before triggers similar to Oracle". Interested friends may wish to have a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn "how SqlServer implements before triggers similar to Oracle".

1. Determine whether the data exists before inserting the data

SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO-Author:-- Create date:-- Description:-- = alter TRIGGER CategoryExistTrigger ON ProductCategory instead of insert AS declare @ categoryName varchar (50); BEGIN-- SET NOCOUNT ON added to prevent extra result sets from-- interfering with SELECT statements. SET NOCOUNT ON;-- Insert statements for trigger here select @ categoryName = CategoryName from inserted; if exists (select * from ProductCategory where CategoryName = @ categoryName) begin print 'Category exists..' End; else begin insert into ProductCategory select * from inserted; end; END

two。 When deleting the data in the table, you need to delete the data in the foreign key table first.

SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO-- =-- Author:-- Create date:-- Description:-- = alter TRIGGER DeleteOrderTrigger ON OrderHeader instead of delete AS declare @ OrderId varchar (50); BEGIN SET NOCOUNT ON; select @ OrderId = OrderId from deleted; delete from OrderLine where OrderId = @ OrderId; END GO so far, I believe you have a deeper understanding of "how SqlServer implements before triggers similar to Oracle". You might as well do it in practice! Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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