Question

I have two datasets on two seperate servers. They both pull one column of information each.

I would like to build a report showing the values of the rows that only appear in one of the datasets.

From what I have read, it seems I would like to do this on the SQL side, not the reporting side; I am not sure how to do that.

If someone could shed some light on how that is possible, I would really appreciate it.

Answer 1

You can use the NOT EXISTS clause to get the differences between the two tables.

SELECT
    Column
FROM
    DatabaseName.SchemaName.Table1
WHERE
    NOT EXISTS
    (
        SELECT
            Column
        FROM
            LinkedServerName.DatabaseName.SchemaName.Table2
        WHERE
            Table1.Column = Table2.Column --looks at equalities, and doesn't
                                          --include them because of the
                                          --NOT EXISTS clause
    )

This will show the rows in Table1 that don’t appear in Table2. You can reverse the table names to find the rows in Table2 that don’t appear in Table1.

Edit: Made an edit to show what the case would be in the event of linked servers. Also, if you wanted to see all of the rows that are not shared in both tables at the same time, you can try something as in the below.

SELECT
    Column, 'Table1' TableName
FROM
    DatabaseName.SchemaName.Table1
WHERE
    NOT EXISTS
    (
        SELECT
            Column
        FROM
            LinkedServerName.DatabaseName.SchemaName.Table2
        WHERE
            Table1.Column = Table2.Column --looks at equalities, and doesn't
                                          --include them because of the
                                          --NOT EXISTS clause
    )

UNION

SELECT
    Column, 'Table2' TableName
FROM
    LinkedServerName.DatabaseName.SchemaName.Table2
WHERE
    NOT EXISTS
    (
        SELECT
            Column
        FROM
            DatabaseName.SchemaName.Table1
        WHERE
            Table1.Column = Table2.Column
    )