Ordering in SQL Server | 易学教程

问题

I have a situation where I am importing many rows of data from text files. The import process occurs using SqlBulkCopy and initially loads into a staging table.

I perform some validation on this data and would like to be able to report back to the user which line of the file is in error if validation fails. I was hoping to simply use ROW_NUMBER() along with the default ordering of the SELECT on my staging table, but there are some questions on SO that have suggested I won't be able to do this.

What would you suggest as a method to allow me to retain the original order of the input file? The input file format is TSV. Do I need to create a mock value indicating file-line?

Is there any way to report the result of the query in the order of the original insertions? Could I rely on this given I used SqlBulkCopy to load the date en masse?

回答1:

I found that I am able to preserve source table order using BULK INSERT into a file, followed by adding an identity.

Given a tab-delimited table, C:\MyTable.txt, where I intentionally moved rows out of order:

FileName    FileType
wmsetup log
bar txt
wmsetup10   log
WMSysPr9    prx
WMSysPrx    prx
Wudf01000Inst   log
xpsp1hfm    log
_default    pif
0   log
002391_ tmp
005766_ tmp

I ran the following and preserved the text file order in SQL Server:

IF EXISTS(
    SELECT 1
    FROM sys.tables t
    INNER JOIN sys.schemas s on s.schema_id=t.schema_id
    WHERE t.name='myTable'
    AND t.[type]='U'
    AND s.name='dbo'
)
DROP TABLE myTable
GO

CREATE TABLE dbo.myTable(FileName VARCHAR(80), FileType VARCHAR(30))
GO

BULK INSERT myTable FROM 'C:\MyTable.txt' WITH (
firstrow=2
, fieldterminator='\t'
, rowterminator='\n'
)
GO

ALTER TABLE myTable ADD ID INT IDENTITY(1,1)
GO

SELECT * FROM myTable
GO

Result:

FileName        FileType ID
--------------- -------- -----------
wmsetup         log      1
bar             txt      2
wmsetup10       log      3
WMSysPr9        prx      4
WMSysPrx        prx      5
Wudf01000Inst   log      6
xpsp1hfm        log      7
_default        pif      8
0               log      9
002391_         tmp      10
005766_         tmp      11

来源：https://stackoverflow.com/questions/10767101/ordering-in-sql-server

标签

sql-server-2008

sqlbulkcopy