Question

Below is my sql:

SELECT DISTINCT
    U.[IP Address],
    U.[Risk Rating],
    COUNT( U.[IP Address] ) AS UNIXIP,
    COUNT( U.[Risk Rating] ) RATINGCOUNT
FROM
    Exception AS E
LEFT JOIN
    tblUNIX_Archive AS U
        ON E.IP_address <> U.[IP Address]  -- Is using '<>' ok? instead of =
        AND (U.ScanDate BETWEEN '2011-01-22' AND '2011-02-18')
group by
    U.[Risk Rating],
    U.[IP Address]
ORDER BY
    U.[Risk Rating],
    U.[IP Address]

i only need to see the unique IP Address that are not in Exception table that are in tblUNIX_Archive table. I am getting multiple records. What am I doing wrong with the above sql?

Answer 1

to select the records in one table that aren’t in another you don’t have to use join, you have to use NOT IN

SELECT DISTINCT
    U.[IP Address],
    U.[Risk Rating],
    COUNT( U.[IP Address] ) AS UNIXIP,
    COUNT( U.[Risk Rating] ) RATINGCOUNT
FROM
    tblUNIX_Archive AS U
where  U.[IP Address] NOT IN( select E.IP_address  from Exception AS E)
        AND (U.ScanDate BETWEEN '2011-01-22' AND '2011-02-18')
group by
    U.[Risk Rating],
    U.[IP Address]
ORDER BY
    U.[Risk Rating],
    U.[IP Address]