Incomparable Columns message

Brian DonahueBrian Donahue Posts: 6,590 New member
Hi Dave,

I think you've come within a millimetre of answering your own question!
On the unique identifier column you speak of, you'll probably notice that
the IsRowGuid property is set to yes. If you were to set this to No, Data
Compare wouldn't tell you about incomperable columns.

Brian Donahue

Technical Support Engineer

Red Gate Software Ltd.

+44 870 1600 037

mailto:[email protected]



"Dave Hall" <[email protected]> wrote in message
news:[email protected]
> I'm comparing 13 tables on two SQL servers. SQL Compare shows the schema
is
> identical on both server. All of the tables correctly show the data that
is
> out of sync, but three of the tables have a comment which says "Has
> incomparable columns." Any idea why I'm getting this message, and why it's
> only on three of the 13 tables? I don't know if this is related to the
> problem or not, but all three of the tables are empty in one database and
> have less than 5 records in the other. One of the tables has a single
field
> which is a uniqueidentifier and is the primary key. The other two tables
> that show the "incomparable columns" comment have foreign key columns
which
> reference the table with the single uniqueidentifier column.
>
>

Comments

  • Brian DonahueBrian Donahue Posts: 6,590 New member
    Hi Dave,

    Usually, something like a ROWGUID column is used for replication
    purposes to uniquely identify rows as they are added to the database. It
    would be impossible to synchronize a ROWGUID column because it's like an
    identity column, only using Global Unique Identifiers. Every time a new row
    is added, the newid() function is called to fill in the value. If you're not
    using these columns for replication, I can't see a reason why you would want
    to set IsRowGuid to yes.

    Hope this helps.

    Brian Donahue

    Technical Support Engineer

    Red Gate Software Ltd.

    +44 870 1600 037

    mailto:[email protected]



    "Dave Hall" <[email protected]> wrote in message
    news:[email protected]
    > Thanks for the quick response Brian. I turned off IsRowGUID on the three
    > tables, and the message disappeared. I have other databases where all of
    the
    > primary keys have IsRowGUID set to yes, so I'd expect to see this message
    if
    > I compare data in any of them (although I haven't tried it yet). Can you
    > give me a little insight as to what's going on here? I don't understand
    why
    > this setting would indicate that anything in the two databases in
    > incomparable. A quick review of ISRowGUID in the SQL books online doesn't
    > shed help either. I haven't found any place where the setting actually
    makes
    > any difference in any of my applications, so I'm not sure what's the best
    > way to set this option when I design a database. Can you shed any light on
    > how this setting is used, and why SQL Data Compare cares about it?
    >
    > Thanks,
    > Dave
    >
    >
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