Question

I have the following unique contstraint defiend on a table:

CREATE UNIQUE NONCLUSTERED INDEX [IX_Access_AccessSOE] ON [dbo].[Access] 
(
    [AccessSOE] ASC
)

I am trying to import records to this table using the following query:

INSERT INTO Access 
  (AccessSOE, AccessName, AccessBox, AccessLocation, 
   AccessBusiness, AccessPhone, AccessFax, AccessEmail,
   LastUpdatedBy, Deleted, AccessPrimaryKey)
SELECT DISTINCT(i.AccessSOE), i.AccessName, i.AccessBox, i.AccessLocation,
       i.AccessBusiness, i.AccessPhone, i.AccessFax, i.AccessEmail,
       'Admin', 0, i.IndexNew
  FROM Access_IMPORT i
 WHERE i.AccessSOE NOT IN (SELECT a.AccessSOE FROM ACCESS a)

However the import fails. The only unique constraint on the table is the AccessSOE field, and I thought by selecting only distinct items, my query would be correct.

Can anyone provide any help?

Answer 1

First, try changing

Where i.AccessSOE not in (Select a.AccessSOE from Access a)

Into:

Where NOT EXISTS
    (SELECT * FROM Access a WHERE a.AccessSOE = i.AccessSOE)

Any NULLs here will Select a.AccessSOE from Access a cause the entire NOT IN to be false

Then, check you haven’t duplicates in what you insert. DISTINCT applies to all columns BTW

SELECT COUNT(*), i.AccessSOE, i.AccessName, i.AccessBox, i.AccessLocation,
       i.AccessBusiness, i.AccessPhone, i.AccessFax, i.AccessEmail,
       'Admin', 0, i.IndexNew
  FROM Access_IMPORT i
 where NOT EXISTS
        (SELECT * FROM Access a WHERE a.AccessSOE = i.AccessSOE)
GROUP BY
      i.AccessSOE, i.AccessName, i.AccessBox, i.AccessLocation,
       i.AccessBusiness, i.AccessPhone, i.AccessFax, i.AccessEmail,
       'Admin', 0, i.IndexNew
HAVING COUNT(*) > 1