This section describes how to use mysqldump to create delimited-text dump files. For information about reloading such dump files, see Section 6.4.4, “Reloading Delimited-Text Format Backups”.
If you invoke mysqldump with the
--tab=
option, it uses dir_name
dir_name
as the
output directory and dumps tables individually in that directory
using two files for each table. The table name is the basename
for these files. For a table named t1
, the
files are named t1.sql
and
t1.txt
. The .sql
file
contains a CREATE TABLE
statement
for the table. The .txt
file contains the
table data, one line per table row.
The following command dumps the contents of the
db1
database to files in the
/tmp
database:
shell> mysqldump --tab=/tmp db1
The .txt
files containing table data are
written by the server, so they are owned by the system account
used for running the server. The server uses
SELECT ... INTO
OUTFILE
to write the files, so you must have the
FILE
privilege to perform this
operation, and an error occurs if a given
.txt
file already exists.
The server sends the CREATE
definitions for
dumped tables to mysqldump, which writes them
to .sql
files. These files therefore are
owned by the user who executes mysqldump.
It is best that --tab
be used
only for dumping a local server. If you use it with a remote
server, the --tab
directory
must exist on both the local and remote hosts, and the
.txt
files will be written by the server in
the remote directory (on the server host), whereas the
.sql
files will be written by
mysqldump in the local directory (on the
client host).
For mysqldump --tab, the server by default
writes table data to .txt
files one line
per row with tabs between column values, no quotes around column
values, and newline as the line terminator. (These are the same
defaults as for SELECT
... INTO OUTFILE
.)
To enable data files to be written using a different format, mysqldump supports these options:
The string for separating column values (default: tab).
The character within which to enclose column values (default: no character).
--fields-optionally-enclosed-by=
char
The character within which to enclose non-numeric column values (default: no character).
The character for escaping special characters (default: no escaping).
The line-termination string (default: newline).
Depending on the value you specify for any of these options, it
might be necessary on the command line to quote or escape the
value appropriately for your command interpreter. Alternatively,
specify the value using hex notation. Suppose that you want
mysqldump to quote column values within
double quotes. To do so, specify double quote as the value for
the
--fields-enclosed-by
option. But this character is often special to command
interpreters and must be treated specially. For example, on
Unix, you can quote the double quote like this:
--fields-enclosed-by='"'
On any platform, you can specify the value in hex:
--fields-enclosed-by=0x22
It is common to use several of the data-formatting options
together. For example, to dump tables in comma-separated values
format with lines terminated by carriage-return/newline pairs
(\r\n
), use this command (enter it on a
single line):
shell>mysqldump --tab=/tmp --fields-terminated-by=,
--fields-enclosed-by='"' --lines-terminated-by=0x0d0a db1
Should you use any of the data-formatting options to dump table data, you will need to specify the same format when you reload data files later, to ensure proper interpretation of the file contents.
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