SQL Trigger update another table

Question

I am newbie to triggers... can anybody help me with a trigger?

I have Table:

Name | Number

I want to write a trigger when my table receives a query like

update MyTable 
set Number = Number + 1 
where Name = 'myname'

When this query is running, the trigger should update another table for example:

Update MyTable 2 
set Column = 'something' 
where Name = 'myname (above name)

Thank you very much !

Answer 1

You will need to write an UPDATE trigger on table 1, to update table 2 accordingly.

Be aware : triggers in SQL Server are not called once per row that gets updated - they're called once per statement , and the internal "pseudo" tables Inserted and Deleted will contain multiple rows , so you need to take that into account when writing your trigger.

In your case, I'd write something like:

-- UPDATE trigger on "dbo.Table1"
CREATE TRIGGER Table1Updated
ON dbo.table1 FOR UPDATE
AS 
BEGIN
    -- update table2, using the same rows as were updated in table1
    UPDATE t2
    SET t2.Column = 'something'
    FROM dbo.Table2 t2
    INNER JOIN Inserted i ON t2.ID = i.ID        
END
GO

The trick is to use the Inserted pseudo table (which contains the new values after the UPDATE - it has the exact same structure as your table the trigger is written for - here dbo.Table1 ) in a set-based fashion - join that to your dbo.Table2 on some column that they have in common (an ID or something).

Answer 2

create a trigger on table 1 for update:

CREATE TRIGGER dbo.update_trigger 
   ON  table1
   AFTER UPDATE
AS 
BEGIN
    DECLARE @Name VARCHAR(50)
    SELECT @Name=Name FROM INSERTED
    Update MyTable 2 
        SET Column = 'something' 
        WHERE Name = @Name
END
GO

try this ;)