Insert into Table B from Table A using Distinct - sql-server

Question

I have 2 tables
Table A
NameID FirstName MiddleName LastName Addr1 Addr2 Phn1 Phn2 City State
NULL Micheal Calvin Dodson 12 23 1234 123 XYZ ABC
NULL John NULL Keith NULL NULL 2344 NULL SQE FDG
NULL John NULL Keith NULL NULL 2344 NULL SQE FDG
NULL William Stephen NULL 45 NULL NULL NULL HJD ABC
NULL Victor NULL Anthony NULL NULL NULL NULL NULL NULL
Table B
NameID FirstName MiddleName LastName Addr1 Addr2 Phn1 Phn2 City State Zip Email Gender...
I need to get the distinct records of (FirstName,MiddleName,LastName) of Table A and insert the same details along with the other fields matching with Table A into Table B.
My Table B has NameID as an identity coloum. So after inserting a unique record into Table B, I need to get that NameID and insert it back into Table A shown below :
TABLE A
Table A
NameID FirstName MiddleName LastName Addr1 Addr2 Phn1 Phn2 City State
1 Micheal Calvin Dodson 12 23 1234 123 XYZ ABC
2 John NULL Keith NULL NULL 2344 NULL SQE FDG
2 John NULL Keith NULL NULL 2344 NULL SQE FDG
3 William Stephen NULL 45 NULL NULL NULL HJD ABC
4 Victor NULL Anthony NULL NULL NULL NULL NULL NULL
TABLE B
NameID FirstName MiddleName LastName Addr1 Addr2 Phn1 Phn2 City State Zip Email Gender...
1 Micheal Calvin Dodson 12 23 1234 123 XYZ ABC NULL NULL NULL
2 John NULL Keith NULL NULL 2344 NULL SQE FDG NULL NULL NULL
3 William Stephen NULL 45 NULL NULL NULL HJD ABC NULL NULL NULL
4 Victor NULL Anthony NULL NULL NULL NULL NULL NULL NULL NULL NULL
Can you please help me with this. Im not able to get this query right. Code in SQL Server 2008
Thanks in advance,
Sunitha

Answer 1

I think the easiest way to do this is with two queries. The first problem is handling duplicates in TableA. The following query selects an arbitrary row for each name combination:
insert into TableB()
select ()
from (select a.*,
row_number() over (partition by FirstName, MiddleName, LastName order by FirstName) as seqnum
from TableA a
) a
where seqnum = 1
Then, update the original table:
update TableA
set NameId = (select max(NameId) from TableB
where TableB.FirstName = TableA.FirstName and
TableB.MiddleName = TableA.MiddleName and
TableB.LastName = TableA.LastName
)
where NameId is null
If your fields contain NULL values (rather than blanks), you can use coalesce() for the join conditions:
update TableA
set NameId = (select max(NameId) from TableB
where coalesce(TableB.FirstName, '<null>') = coalesce(TableA.FirstName, '<null>') and
coalesce(TableB.MiddleName, '<null>') = coalesce(TableA.MiddleName, '<null>') and
coalesce(TableB.LastName , '<null>')= coalesce(TableA.LastName, '<null>')
)
where NameId is null

Answer 2

DECLARE #results TABLE
(
NameID INT,
FirstName VARCHAR(32), -- guessing on data types for these columns
MiddleName VARCHAR(32),
LastName VARCHAR(32)
);
;WITH x AS
(
SELECT FirstName, MiddleName, LastName,
rn = ROW_NUMBER() OVER (PARTITION BY FirstName, MiddleName, LastName
ORDER BY (SELECT NULL)
) --, ... other columns ...
FROM dbo.TableA
)
INSERT dbo.TableB
(
FirstName, MiddleName, LastName --, ... other columns ...
)
OUTPUT
inserted.NameID, inserted.FirstName,
inserted.MiddleName, inserted.LastName
INTO #results
SELECT FirstName, MiddleName, LastName --, ... other columns ...
FROM x WHERE rn = 1;
UPDATE a SET NameID = r.NameID
FROM dbo.TableA AS a
INNER JOIN #results AS r
ON COALESCE(a.FirstName,'') = COALESCE(r.FirstName,'')
AND COALESCE(a.MiddleName,'') = COALESCE(r.MiddleName,'')
AND COALESCE(a.LastName,'') = COALESCE(r.LastName,'');