INF: Commonly Asked BCP Utility Questions in SQLID: Q67409
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The Bulk Copy Program (BCP) is a utility for copying large amounts of data into or out of SQL Server. BCP is mainly used to copy data from a SQL Server for use with other programs (spreadsheets), to upload data files from different databases, and to copy information from one SQL Server to another SQL Server. Below is a list of commonly asked questions and problems that users experience while using the BCP utility.
Q. Could you please explain how to use the BCP format file?
A. The BCP format file provides an alternative way to use the BCP
utility and adds flexibility to the program. The following example
of a format file illustrates the use of BCP on an ASCII data file
BCP Format File
---------------
4.2
4
1 sybchar 0 12 "" 1 f_name
2 sybchar 0 15 "" 2 l_name
3 sybchar 0 15 "," 3 city
4 sybchar 0 2 "\r\n" 4 state
where:
Row Description
--- -----------
1 Indicates the version number of BCP.
2 Represents the number of fields in the data file.
Column Description
------ -----------
1 Designates the field number of the data file.
2 Indicates the data type that is stored in the particular
field of the data file. For ASCII data files, use "sybchar";
and for native format data files, use the default data
types.
3 Indicates the prefix length, which is used to provide the
most compact file storage. For ASCII data files, use 0.
4 Represents the length of the particular data file field.
5 Represents the field terminator. Common field terminators
are commas and end of line characters (\r\n).
6 Indicates the column number of the table in the SQL Server
database.
7 Gives the name of the field taken from the SQL table. It is
not necessary to use the actual name of the field. However,
the only condition is that it cannot be blank.
Q. What is the difference between data in ASCII format and data in
native format, and how does the data format relate to BCP?
A. The information in BCP data files can be stored in two ways: ASCII
and native format.
In ASCII data files, the information is stored as ASCII characters.
This format is useful if the data will be used with another
program, such as a spreadsheet, or if the data is to be uploaded to
SQL Server from some other database. The BCP format file described
in question 1 is an example of a format file that could be used to
BCP ASCII data out of or into SQL Server. Note that all data types
are defined to be "sybchar" and have a prefix length of 0. The SQL
Server engine performs all the data type conversions.
The native format file contains the data's "native" data types as
defined in the SQL Server database. Native format proves to be most
useful when information is to be BCP'd out of one SQL Server and
into a different SQL Server. The use of the native format saves
time by eliminating the unnecessary conversion of data types into
and out of character format. The following is an example of a
native format BCP format file:
BCP Format File
---------------
4.2
5
1 sybchar 1 512 "" 1 discnttype
2 sybchar 1 512 "" 2 stor_id
3 sybint2 1 2 "" 3 lowqty
4 sybint2 1 2 "" 4 highqty
5 sybflt8 0 8 "" 5 discount
This particular format file was created by BCP'ing data out of the
"discount" table from the "pubs" database and taking all default
values for the fields.
Q. What is the proper way to use the field length column and the
delimiter column? How can they work with or against each other?
A. Data can be field delimited either by a character set or by a
specified fixed length. It can also be delimited using a
combination of both character set and fixed length. However,
caution must be taken. The BCP utility will take the first form of
the delimiter it finds. For example, if the field is comma
delimited and all elements in the field have at least 10
characters, and the length is set at 8, BCP will copy only the
first 8 characters of all elements in that field. This mistake will
most likely result in an error message from BCP. It is easiest to
use the default option of fixed-length terminators for native
format files.
Q. What is the best way to create a format file to BCP my ASCII data
into SQL Server?
A. To create a format file that is easily modified, start the BCP
utility by using the following command line:
bcp <db_name>.<owner>.<table> out <data_file> /S<server> /Usa /P<password>
When you start the program, a series of questions is asked. Choose
all the default options. When prompted to save the information in a
BCP format file, press Y, then ENTER. Then edit the format file to
have data types of "sybchar" and a prefix length of 0 (zero), and
enter the proper length and/or field terminators.
After this process is completed, run the BCP utility with the
/f <bcp.fmt> option. This option tells BCP to use the specified BCP
format file.
Q. Now that I know the structure and usage of the BCP format file, how
can I use it to ignore extra columns in my ASCII file?
A. If you have a data file that contains more fields than the table on
SQL Server, you can redirect these unneeded fields to a null field,
as in the following example, where the user wants to copy in the
fields "f_name", "l_name", and "state", but does not want to make
use of the "city" field that exists in the data file. The following
is an example of both the data file and the BCP format file:
ASCII Data File
---------------
Howard Jones San Jose,CA
William Smith Seattle,WA
Anthony Henry Portland,OR
BCP Format File
---------------
4.2
4
1 sybchar 0 10 "" 2 f_name
2 sybchar 0 10 "" 1 l_name
3 sybchar 0 15 "," 0 city
4 sybchar 0 2 "\r\n" 3 state
Please note that on the fifth line of the BCP format file, the SQL
Server table field designation (column 6) is 0 and the table field
name (column 7) still has some form of an entry. The use of 0 in
column 6 will allow any information between column 20 and the comma
in the data file to be placed in the null field device (the city
fields). The use of column 7 is to avoid a BCP syntax error and is
useful in self documentation.
Q. What are the most common problems seen when using BCP? What are the
symptoms? And how do you solve the problems?
A. The most common problems users have when using BCP fall into the
following categories:
* Trying to load native format.
Users often try to load an ASCII file using the SQL Server
native format. This results in all the hexadecimal values of the
ASCII file being misinterpreted. An "unexpected end of file"
error message is very common in this instance. The proper way to
load the ASCII file is to represent the fields as character
strings and to let SQL Server perform the data conversion.
* Using the default size of the data type.
Using the default size can sometimes lead to the same error as
above ("unexpected end of file"). This is most common with the
SQL Server money and date data types. For example, if the user
does not insert the entire date string, but only a fraction of
the entire date (that is, mm/dd/yy with no time), the default
size option reads 25 characters, the length of the date type.
The solution is to use delimiters or a user-defined, fixed-
length ASCII file.
* Hidden characters in the data file.
Often a hidden character in an ASCII data file can cause
problems when the BCP command is used. This problem usually
masks itself in an "unexpected null found" error. This character
usually can be found at the bottom of the file. Many utilities
display hidden characters; finding and removing this hidden
character should resolve the problem.
* Using spaces for delimiters in a data file.
Using the BCP command with the format file on a data file
delimited with spaces returns the following error message "dblib
error: column number out of range." To avoid this problem, run
BCP without a format file by using the -t option on the command
line. For example:
bcp dbase..table out file.out -SServer -Usa -P -r\r\n -c -t" " Additional query words: Windows NT
Keywords : kbtool SSrvBCP SSrvWinNT
Version : 4.2 | 4.2
Platform : OS/2 WINDOWS
Issue type : Last Reviewed: March 10, 1999