Comparing Column Values in T-SQL

Okay… so here's the scenario. I have two different tables in a SQL Database, where I need to compare both tables, and find all values in Table B that do not exist in Table A. There are two ways to do this. One with a JOIN, and one with a "NOT EXISTS" Clause:


Method 1:


SELECT b.[ColumnName]

    FROM DBName.dbo.tblB b

    LEFT OUTER JOIN DBName.dbo.tblA a

    ON b.[ColumnName] = a.[ColumnName]

    WHERE a.[ColumnName] IS NULL

    GROUP BY b.[ColumnName];

Method 2:


SELECT b.[ColumnName]

    FROM DBName.dbo.tblB b



        SELECT *

            FROM DBName.dbo.tblA

            WHERE a.[ColumnName] = b.[ColumnName]


    GROUP BY b.[ColumnName];


I hope this helps someone! My malformed queries have been driving me nuts all week…