SQL Triggers to duplicate update changes to another table

问题

So I have an intermitant problem that I need a temporary fix for.

(something is causing issues with two tables intermittently (every 3-4 weeks))

One table gets completly cleared out and another seems to have individual records removed...

as this is an ongoing issue we are still investigating the main cause but need a temporary fix.

As such I have setup a second "Backup" table for each of these tables and am trying to setup triggers to copy ALL Insert and Update commands

I have created the Insert triggers with no problem.

ALTER Trigger [dbo].[MainInsertBackup] 
On [dbo].[tblMain] AFTER INSERT AS 
BEGIN 
    INSERT INTO tblMainBackup 
    SELECT * FROM inserted 
END

now I need a trigger that does the same for updates (performs the updates on the tblMainBackup).

this way I should ensure that the backup table has all of the information from the main but if a record is removed somehow it can be copied back to the main table from the backup table.

Only examples I have found perform updates in individual fields on the update, or insert a whole new record on the update into a log table.

any help is apriciated.

回答1:

You can try to use this UPDATE trigger to update the rows in tblMainbackup while update row in tblMain table

CREATE Trigger [dbo].[MainUpdateBackup] 
On [dbo].[tblMain] AFTER UPDATE AS 
BEGIN     
    UPDATE tblMainbackup
    SET tblMainbackup.col1 = i1.col1,
        tblMainbackup.col2 = i1.col2,
        tblMainbackup.col3 = i1.col3    
    FROM tblMainbackup t1
          INNER JOIN inserted i1
          ON t1.Id = i1.ID
END

来源：https://stackoverflow.com/questions/27903254/sql-triggers-to-duplicate-update-changes-to-another-table

标签

sql

triggers

backup