Left Join & where

[mikerh9]

I have 2 tables. I want to select only these items that doesn't exist in table #2.
So I perform the following SELECT

SELECT table1.update, table1.id from tabl1 LEFT table2 ON table1.id != table2.table1_id

where table2.table1_id != table1.id

The query returns nothing. Because of this part "where table2.table1_id != table1.id".
This means select only this rows that doesn't exist in table2. (this statement fails to do so Any ideas why?)

[tomhath]

Use the WHERE to select rows that failed to find a match in the LEFT JOIN

SELECT table1.update, table1.id 
from table1 
LEFT JOIN table2 
ON table1.id = table2.table1_id
where table2.table1_id is null