How to use update trigger to update another table?

Question

I am new to triggers and want to create a trigger on an update of a column and update another table with that value.

I have table1 with a year column and if the application updates that year column I need to update table 2 with the year the same year.

ALTER TRIGGER [dbo].[trig_UpdateAnnualYear]    ON  [dbo].[table1]    AFTER UPDATE AS   if (UPDATE (intAnnualYear))    BEGIN     -- SET NOCOUNT ON added to prevent extra result sets from     -- interfering with SELECT statements.     SET NOCOUNT ON;      -- Insert statements for trigger here      Update table2 set AnnualYear = intAnnualYear where table2.ID = table1.ID END 

Answer 1

You don't reference table1 inside the trigger. Use the inserted pseudo table to get the "after" values. Also remember that an update can affect multiple rows.

So replace your current update statement with

UPDATE table2 SET    table2.annualyear = inserted.intannualyear FROM   table2        JOIN inserted          ON table2.id = inserted.id   

Answer 2

You only need to update the records in table2 if the column intannualyear is involved. Also, this is an alternative UPDATE syntax across two tables from what Martin has shown

IF UPDATE(intannualyear)     UPDATE table2     SET    annualyear = inserted.intannualyear     FROM   inserted     WHERE table2.id = inserted.id