在SQL Server中插入后更新触发器c＃

Question

Here's the scenario I've been stuck on:

• User INSERTS a book into books table
• Books Collection UPDATES with the userid and the INSERTED bookid in bookscollection

Userid is passed from a string username in c# application.

bookcollection bookc_id, bookc_bookid, bookc_bookuser
books bookid, title, author, year
users userid, username, password

bookid is foreign key to bookc_bookid

userid is a foreign key to bookc_bookuser

This is how it gets inserted into books table

INSERT INTO books (title, author, year) VALUES (@title, @author, @year);

In a previous form I have used INNER JOIN clause to retrieve information from books collection based on the logged in Username string.

 SELECT * FROM bookcollection c 
 INNER JOIN users r ON c.bookC_userid = r.userid 
 INNER JOIN books b ON c.bookC_bookID = b.bookid 
 WHERE username LIKE '" + Username + "'"

How could I create a trigger which would update the books table with the userid and bookid.

Answer 1

Simple you can create a update Trigger Like this

CREATE TRIGGER yourtriggername
     ON yourtablename
     AFTER  INSERT
AS
BEGIN
 /* here goes your update statement*/
   UPDATE c
   SET c.bookC_userid = r.userid,
   b.bookC_bookID= b.bookid 
   FROM bookcollection c 
   INNER JOIN users r ON c.bookC_userid = r.userid 
   INNER JOIN books b ON c.bookC_bookID = b.bookid
   Where b.bookid = SCOPE_IDENTITY(); 
end 

Edit: You can get newly inserted id of yourtable by Scope_Identity function