Import Native and Character Format Data from Earlier Versions of SQL Server

Artykuł
02/13/2015

In SQL Server 2012, you can use bcp to import native and character format data from SQL Server 2000, SQL Server 2005, or SQL Server 2008, by using the -V switch. The -V switch causes SQL Server 2012 to use data types from the specified earlier version of SQL Server, and the data file format are the same as the format in that earlier version.

To specify an earlier SQL Server version for a data file, use the -V switch with one of the following qualifiers:

SQL Server version	Qualifier
SQL Server 2000	-V 80
SQL Server 2005	-V 90
SQL Server 2008	-V 100

Interpretation of Data Types That Were Introduced in SQL Server 2005

SQL Server 2005 and later versions have support for some new types. When you want to import a new data type into an earlier SQL Server version, the data type must be stored in a format that readable by the older bcp clients. The following table summarizes how the new data types of SQL Server 2005 are converted for compatibility with the earlier versions of SQL Server.

New data types in SQL Server 2005	Compatible data types in version 6x	Compatible data types in version 70	Compatible data types in version 80
bigint	decimal	decimal	*
sql_variant	text	nvarchar(4000)	*
varchar(max)	text	text	text
nvarchar(max)	ntext	ntext	ntext
varbinary(max)	image	image	image
XML	ntext	ntext	ntext
UDT1	image	image	image

* This type is natively supported.

1 UDT indicates a user defined type.

Exporting from SQL Server 2005 and Later Versions

When you bulk export data by using the –V 80 switch from SQL Server 2005 or later versions, nvarchar(max), varchar(max), varbinary(max), XML, and UDT data in native mode are stored with a 4-byte prefix, like text, image, and ntext data, rather than with an 8-byte prefix, which is the default for SQL Server 2005 and later versions.

Copying Date Values

bcp uses the ODBC bulk copy API. Therefore, to import date values into SQL Server, bcp uses the ODBC date format (yyyy-mm-dd hh:mm:ss[.f...]).

The bcp command exports character format data files using the ODBC default format for datetime and smalldatetime values. For example, a datetime column containing the date 12 Aug 1998 is bulk copied to a data file as the character string 1998-08-12 00:00:00.000.

Ważne:
When importing data into a smalldatetime field using bcp, be sure the value for seconds is 00.000; otherwise the operation will fail. The smalldatetime data type only holds values to the nearest minute. BULK INSERT and INSERT ... SELECT * FROM OPENROWSET(BULK...) will not fail in this instance but will truncate the seconds value.