>>Hello!
>>I was just wondering if i can write a query that selects all the data not found in another table. like
>>select *
>>from table
>>where 100 is in one table... but not in the other table
>>?
>
>Try this syntax
>

>SELECT T1.* from myTable T1 LEFT JOIN myOtherTable T2 on T1.ID = T2.ID where T2.ID IS NULL
>

>This syntax is more robust than the other (in case you have NULLs in T2.ID) it would not select anything if using NOT IN syntax.
>
>In addition, it's more likely to be more performant.
>
>See also this link
>
>http://blogs.lessthandot.com/index.php/DataMgmt/DataDesign/the-ten-most-asked-sql-server-questions--1#4

Ah you are right partially. Nulls are evils. A join would too erroneously select rows with null values on left:)

Performance wise I disagree join perfroms better. Last time I tested them I remember join was the slowest of all (this year).
Cetin