Update local table from linked server (Excel file)

SQLServerCentral is supported by Red Gate Software Ltd.

Popular Topics

Home

Members

Calendar

Who's On

Home » SQL Server 2008 » SQL Server Newbies » Update local table from linked server (Excel...

Update local table from linked server (Excel file)

Rate Topic

Display Mode

Topic Options

Author

Message

jmenax

Posted Thursday, December 06, 2012 10:19 AM

Forum Newbie

Group: General Forum Members
Last Login: Wednesday, February 13, 2013 6:36 AM
Points: 5, Visits: 31

Hi there,

I am a newbie in Sql Server querys, and I really need some help with a task that have been assigned to me. I need to update a table in one of the server databases with some info from an Excel Worksheet. For example, I have to change the wharehouse id from some items in the table, for the new ones as they appear in the excel sheet.

As they appear in the database:

ItemID___Wharehouse

1---------external
2---------external
3---------internalD
4---------internalE

As they appear in the excel Sheet:
1---------obsolete
2---------obsolete
3---------fullinternal
4---------fullinternal

I already put a linked server that points to the excel sheet, and when i query all the data (select * from SELECT * FROM ExcelDataSource...sheet1$) i can see all the data from excel.

At this point everything is ok. But I need to make an UPDATE of the data, so if the itemid exists in the linkedserver, update the wharehouse column data.

Something like this (sorry, is a rough idea):
UPDATE dbo.tabletoupdate
set WHAREHOUSE = sheet1$.WHAREHOUSE
WHERE ItemID = sheet1$.ItemID

Can someone help me get this done? I have searched and read a lot but I have found more information about the reverse process (update the excel file) and not about a scenario like this. And sorry if this have been already covered here, but i havent been able to find it.

Note: I cannot import as a table the excel data as the database have a lot more information detail. The excel sheet have basically just the data to update.

Thanks in advance.

Post #1393640

Lowell

Posted Thursday, December 06, 2012 11:40 AM

SSChampion

Group: General Forum Members
Last Login: Today @ 1:11 PM
Points: 11,605, Visits: 27,645

if you've got the linked server up and running, that's 99% of it;
the rest is just syntax.

something like this is how you update from another table...and it doesn't matter if the other table is local, linked server, etc.
aliases can help a lot here as well;

--syntactically correct, updates all rows, many to same value, most likely
UPDATE dbo.tabletoupdate
SET    WHAREHOUSE = MyExcel.WHAREHOUSE
FROM   ExcelDataSource...sheet1$ MyExcel
WHERE  dbo.tabletoupdate.ItemID = MyExcel.ItemID 


--much more explicit, only change rows that are different
UPDATE MyTargetTable
SET WHAREHOUSE = MyExcel.WHAREHOUSE
FROM dbo.tabletoupdate MyTargetTable
LEFT OUTER JOIN ExcelDataSource...sheet1$ MyExcel
ON  MyTargetTable.ItemID = MyExcel.ItemID
WHERE MyTargetTable.WHAREHOUSE <> MyExcel.WHAREHOUSE

Lowell

--There is no spoon, and there's no default ORDER BY in sql server either.
Actually, Common Sense is so rare, it should be considered a Superpower. --my son

Post #1393678

jmenax

Posted Thursday, December 06, 2012 11:53 AM

Forum Newbie

Group: General Forum Members
Last Login: Wednesday, February 13, 2013 6:36 AM
Points: 5, Visits: 31

Thanks Lowell,
I'll try that as soon as I can, and will let you know how it went.
Regards,

Post #1393684

jmenax

Posted Friday, December 21, 2012 8:44 AM

Forum Newbie

Group: General Forum Members
Last Login: Wednesday, February 13, 2013 6:36 AM
Points: 5, Visits: 31

Hi Lowell,

Sorry for answering until now, but i have been very busy working in another project...

Your guidance was really userful, it worked like a charm!!!

Thank you very much!!! I tested it in a non-working scenario and everything was ok. Now, I will change the table in the production database, but I need to know how to make a proper rollback just in case (I have no problems with my backups), using begin tran / commit tran / rollback tran. Is this recommended? I just want to be sure of the changes and commit those changes, from the management studio, so in case of error recover faster than using the daily backups. (Sorry if this requires to be in a new post. Correct me if it should be.)

Regards,

Post #1399456

Lowell

Posted Friday, December 21, 2012 8:59 AM

SSChampion

Group: General Forum Members
Last Login: Today @ 1:11 PM
Points: 11,605, Visits: 27,645

this is typically how i do it.
1. do a full backup, just in case.
2. SELECT the rows that in theory, should be affected...we might get a specific row count out of this, which we want our update to match:

SELECT *
FROM dbo.tabletoupdate MyTargetTable
LEFT OUTER JOIN ExcelDataSource...sheet1$ MyExcel
ON  MyTargetTable.ItemID = MyExcel.ItemID
WHERE MyTargetTable.WHAREHOUSE <> MyExcel.WHAREHOUSE

3. create an explicit transaction with teh update statement , and let it run:

SET XACT_ABORT ON 
BEGIN TRAN
--much more explicit, only change rows that are different
UPDATE MyTargetTable
SET WHAREHOUSE = MyExcel.WHAREHOUSE
--SELECT *
FROM dbo.tabletoupdate MyTargetTable
LEFT OUTER JOIN ExcelDataSource...sheet1$ MyExcel
ON  MyTargetTable.ItemID = MyExcel.ItemID
WHERE MyTargetTable.WHAREHOUSE <> MyExcel.WHAREHOUSE


--ROLLBACK TRAN
--COMMIT TRAN

4. IMPORTANT Note the above has both COMMIT TRAN and ROLLBACK TRAN COMMENTED OUT! the table's going to be locked untill you are done reviewing and you either commit or rollback!
5. Review the data in general, mae sure it looks good.

SELECT *
FROM dbo.tabletoupdate MyTargetTable
LEFT OUTER JOIN ExcelDataSource...sheet1$ MyExcel
ON  MyTargetTable.ItemID = MyExcel.ItemID

6. lets go ahead and commit, if it's good.

COMMIT TRAN

7. IF it was bad, just ROLLBACK the transaction and start fresh.

ROLLBACK TRAN

Lowell

--There is no spoon, and there's no default ORDER BY in sql server either.
Actually, Common Sense is so rare, it should be considered a Superpower. --my son

Post #1399467

jmenax

Posted Wednesday, January 09, 2013 3:43 PM

Forum Newbie

Group: General Forum Members
Last Login: Wednesday, February 13, 2013 6:36 AM
Points: 5, Visits: 31

Hi Lowell,

Your guidance has been very very helpful. The steps abouve are working really nice. I have updated about 8 tables using these methods, but...there is this one table that wont update, resulting in the following error:

Msg 2627, Level 14, State 1, Line 1
Violation of PRIMARY KEY constraint 'PK_WAREHOUSEINFO'. Cannot insert duplicate key in object 'dbo.WAREHOUSEINFO'.
The statement has been terminated.

This bugs me because apparently this table have the same structure as the ones where the update have worked.

But apart from that, everything is going nice and smooth.
Thanks Lowell!!!

Post #1405056

dwain.c

Posted Wednesday, January 09, 2013 6:29 PM

SSCrazy

Group: General Forum Members
Last Login: Yesterday @ 12:42 AM
Points: 2,338, Visits: 3,158

Lowell (12/6/2012)

--syntactically correct, updates all rows, many to same value, most likely
UPDATE dbo.tabletoupdate
SET    WHAREHOUSE = MyExcel.WHAREHOUSE
FROM   ExcelDataSource...sheet1$ MyExcel
WHERE  dbo.tabletoupdate.ItemID = MyExcel.ItemID 


--much more explicit, only change rows that are different
UPDATE MyTargetTable
SET WHAREHOUSE = MyExcel.WHAREHOUSE
FROM dbo.tabletoupdate MyTargetTable
LEFT OUTER JOIN ExcelDataSource...sheet1$ MyExcel
ON  MyTargetTable.ItemID = MyExcel.ItemID
WHERE MyTargetTable.WHAREHOUSE <> MyExcel.WHAREHOUSE

Good stuff Lowell! Have you ever tried an UPDATE through OPENROWSET like this?

Just wondering, because I haven't either. I've found this kind of integration to Excel to be somewhat of a pain in the past.

No loops! No CURSORs! No RBAR! Hoo-uh!

INDEXing a poor-performing query is like putting sugar on cat food. Yeah, it probably tastes better but are you sure you want to eat it?

Need to UNPIVOT? Why not CROSS APPLY VALUES instead?
Since random numbers are too important to be left to chance, let's generate some!
Are you too recursively challenged?
Splitting strings based on patterns can be fast!

Post #1405104

jmenax

Posted Wednesday, January 09, 2013 6:55 PM

Forum Newbie

Group: General Forum Members
Last Login: Wednesday, February 13, 2013 6:36 AM
Points: 5, Visits: 31

Sorry, I found where the problem was....I know it was obvious but it was killing me...
Of the 30,000 rows of the table with the problem, two of them became duplicated records (with the update), so the query aborted everytime. I made a temporary workaround (manually changing only those 2), so it could not affect the query.

Sorry again, still learning from the experts...
Great forum!
Thanks.

Post #1405116

« Prev Topic | Next Topic »

Permissions