Sunday, March 11, 2012

BULK INSERT ignores UNIQUE index with IGNORE_DUP_KEY set?

All,

Just want to make sure that I understand what's going on here.

I have a table with IGNORE_DUP_KEY set on a unique, multi-column
index.

What I'm seeing is this:

1) When performing a BULK INSERT, the UNIQUE index is not being
respected and rows which violate the unique index are inserted.

2) When performing a regular INSERT, the UNIQUE index is being
respected and rows which violate the unique index ARE NOT inserted.

Is this expected behavior.

Also, I have some questions, given the index described.

Q1) Will a regular INSERT that attempts to insert duplicate data get
an error back or just a warning?

Q2) How can I set things up so that a BULK INSERT would NOT allow
duplicates to be entered into the table?

Thanks,
Wes GambleOn Jun 22, 5:33 pm, Weyus <w...@.att.netwrote:

Quote:

Originally Posted by

All,
>
Just want to make sure that I understand what's going on here.
>
I have a table with IGNORE_DUP_KEY set on a unique, multi-column
index.
>
What I'm seeing is this:
>
1) When performing a BULK INSERT, the UNIQUE index is not being
respected and rows which violate the unique index are inserted.
>
2) When performing a regular INSERT, the UNIQUE index is being
respected and rows which violate the unique index ARE NOT inserted.
>
Is this expected behavior.
>
Also, I have some questions, given the index described.
>
Q1) Will a regular INSERT that attempts to insert duplicate data get
an error back or just a warning?
>
Q2) How can I set things up so that a BULK INSERT would NOT allow
duplicates to be entered into the table?
>
Thanks,
Wes Gamble


I made a logical error that I just realized. The BULK INSERT that I
was doing, in fact did have unique enough data.

However, my question Q1 still stands - what is the behavior of an
INSERT of duplicate data against this type of index - I suspect that
you get a warning
and not an error - is that correct?

Thanks,
Wes|||Weyus (weyus@.att.net) writes:

Quote:

Originally Posted by

Quote:

Originally Posted by

>Q1) Will a regular INSERT that attempts to insert duplicate data get
>an error back or just a warning?
>>...


However, my question Q1 still stands - what is the behavior of an
INSERT of duplicate data against this type of index - I suspect that
you get a warning and not an error - is that correct?


Yes, SQL Server only emits a warning. However, there is a catch, some
client APIs incorrectly interprets this as an error. If run:

CREATE TABLE blamblam (a int NOT NULL)
CREATE UNIQUE INDEX updix ON blamblam(a) WITH IGNORE_DUP_KEY
go
EXEC master..xp_cmdshell 'ECHO 12 C:\temp\blamblam.txt'
EXEC master..xp_cmdshell 'ECHO 12 >C:\temp\blamblam.txt'
go
BULK INSERT blamblam FROM 'C:\temp\blamblam.txt'
go
SELECT * FROM blamblam
go
DROP TABLE blamblam

I get this output from Mgmt Studio:

Duplicate key was ignored.

(1 row(s) affected)
a
----
12

(1 row(s) affected)

But from Query Analyzer, against the same server instance, I get:

Server: Msg 3604, Level 16, State 1, Line 1
Duplicate key was ignored.

a
----
12
(1 row(s) affected)

--
Erland Sommarskog, SQL Server MVP, esquel@.sommarskog.se
Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/pr...oads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodin...ions/books.mspx

No comments:

Post a Comment