(mysql.info.gz) LOAD DATA
(mysql.info.gz) Data Manipulation
13.1.5 `LOAD DATA INFILE' Syntax
LOAD DATA [LOW_PRIORITY | CONCURRENT] [LOCAL] INFILE 'FILE_NAME.txt'
[REPLACE | IGNORE]
INTO TABLE TBL_NAME
[TERMINATED BY '\t']
[[OPTIONALLY] ENCLOSED BY '']
[ESCAPED BY '\\' ]
[STARTING BY '']
[TERMINATED BY '\n']
[IGNORE NUMBER LINES]
The `LOAD DATA INFILE' statement reads rows from a text file into a
table at a very high speed. For more information about the efficiency
of `INSERT' versus `LOAD DATA INFILE' and speeding up `LOAD DATA
INFILE', Insert speed.
You can also load data files by using the `mysqlimport' utility; it
operates by sending a `LOAD DATA INFILE' statement to the server. The
`--local' option causes `mysqlimport' to read data files from the
client host. You can specify the `--compress' option to get better
performance over slow networks if the client and server support the
compressed protocol. `mysqlimport' mysqlimport.
If you specify the `LOW_PRIORITY' keyword, execution of the `LOAD DATA'
statement is delayed until no other clients are reading from the table.
If you specify the `CONCURRENT' keyword with a `MyISAM' table that
satisfies the condition for concurrent inserts (that is, it contains no
free blocks in the middle), then other threads can retrieve data from
the table while `LOAD DATA' is executing. Using this option affects the
performance of `LOAD DATA' a bit, even if no other thread is using the
table at the same time.
If the `LOCAL' keyword is specified, it is interpreted with respect to
the client end of the connection:
* If `LOCAL' is specified, the file is read by the client program on
the client host and sent to the server. The file can be given as a
full pathname to specify its exact location. If given as a
relative pathname, the name is interpreted relative to the
directory in which the client program was started.
* If `LOCAL' is not specified, the file must be located on the
server host and is read directly by the server.
`LOCAL' is available in MySQL 3.22.6 or later.
When locating files on the server host, the server uses the following
* If an absolute pathname is given, the server uses the pathname as
* If a relative pathname with one or more leading components is
given, the server searches for the file relative to the server's
* If a filename with no leading components is given, the server
looks for the file in the database directory of the default
Note that these rules mean that a file named as `./myfile.txt' is read
from the server's data directory, whereas the same file named as
`myfile.txt' is read from the database directory of the default
database. For example, the following `LOAD DATA' statement reads the
file `data.txt' from the database directory for `db1' because `db1' is
the current database, even though the statement explicitly loads the
file into a table in the `db2' database:
mysql> USE db1;
mysql> LOAD DATA INFILE 'data.txt' INTO TABLE db2.my_table;
Note that Windows pathnames are specified using forward slashes rather
than backslashes. If you do use backslashes, you must double them.
For security reasons, when reading text files located on the server, the
files must either reside in the database directory or be readable by
all. Also, to use `LOAD DATA INFILE' on server files, you must have the
`FILE' privilege. Privileges provided.
Using `LOCAL' is a bit slower than letting the server access the files
directly, because the contents of the file must be sent over the
connection by the client to the server. On the other hand, you do not
need the `FILE' privilege to load local files.
As of MySQL 3.23.49 and MySQL 4.0.2 (4.0.13 on Windows), `LOCAL' works
only if your server and your client both have been enabled to allow it.
For example, if `mysqld' was started with `--local-infile=0', `LOCAL'
will not work. `LOAD DATA LOCAL' LOAD DATA LOCAL.
If you need `LOAD DATA' to read from a pipe, you can use the following
technique (here we load the listing of the '/' directory into a table):
chmod 666 /mysql/db/x/x
find / -ls > /mysql/db/x/x
mysql -e "LOAD DATA INFILE 'x' INTO TABLE x" x
If you are using a version of MySQL older than 3.23.25, you can use
this technique only with `LOAD DATA LOCAL INFILE'.
If you are using MySQL before Version 3.23.24, you can't read from a
FIFO with `LOAD DATA INFILE'. If you need to read from a FIFO (for
example, the output from `gunzip'), use `LOAD DATA LOCAL INFILE'
The `REPLACE' and `IGNORE' keywords control handling of input records
that duplicate existing records on unique key values.
If you specify `REPLACE', input rows replace existing rows (in other
words, rows that have the same value for a primary or unique index as an
existing row). `REPLACE' REPLACE.
If you specify `IGNORE', input rows that duplicate an existing row on a
unique key value are skipped. If you don't specify either option, the
behavior depends on whether or not the `LOCAL' keyword is specified.
Without `LOCAL', an error occurs when a duplicate key value is found,
and the rest of the text file is ignored. With `LOCAL', the default
behavior is the same as if `IGNORE' is specified; this is because the
server has no way to stop transmission of the file in the middle of the
If you want to ignore foreign key constraints during the load
operation, you can issue a `SET FOREIGN_KEY_CHECKS=0' statement before
executing `LOAD DATA'.
If you use `LOAD DATA INFILE' on an empty `MyISAM' table, all
non-unique indexes are created in a separate batch (as for `REPAIR
TABLE'). This normally makes `LOAD DATA INFILE' much faster when you
have many indexes. Normally this is very fast, but in some extreme
cases, you can create the indexes even faster by turning them off with
`ALTER TABLE .. DISABLE KEYS' before loading the file into the table
and using `ALTER TABLE .. ENABLE KEYS' to re-create the indexes after
loading the file. Insert speed.
`LOAD DATA INFILE' is the complement of `SELECT ... INTO OUTFILE'.
`SELECT' SELECT. To write data from a table to a file, use
`SELECT ... INTO OUTFILE'. To read the file back into a table, use
`LOAD DATA INFILE'. The syntax of the `FIELDS' and `LINES' clauses is
the same for both statements. Both clauses are optional, but `FIELDS'
must precede `LINES' if both are specified.
If you specify a `FIELDS' clause, each of its subclauses (`TERMINATED
BY', `[OPTIONALLY] ENCLOSED BY', and `ESCAPED BY') is also optional,
except that you must specify at least one of them.
If you don't specify a `FIELDS' clause, the defaults are the same as if
you had written this:
FIELDS TERMINATED BY '\t' ENCLOSED BY '' ESCAPED BY '\\'
If you don't specify a `LINES' clause, the default is the same as if
you had written this:
LINES TERMINATED BY '\n' STARTING BY ''
In other words, the defaults cause `LOAD DATA INFILE' to act as follows
when reading input:
* Look for line boundaries at newlines.
* Do not skip over any line prefix.
* Break lines into fields at tabs.
* Do not expect fields to be enclosed within any quoting characters.
* Interpret occurrences of tab, newline, or `\' preceded by `\' as
literal characters that are part of field values.
Conversely, the defaults cause `SELECT ... INTO OUTFILE' to act as
follows when writing output:
* Write tabs between fields.
* Do not enclose fields within any quoting characters.
* Use `\' to escape instances of tab, newline, or `\' that occur
within field values.
* Write newlines at the ends of lines.
Note that to write `FIELDS ESCAPED BY '\\'', you must specify two
backslashes for the value to be read as a single backslash.
* If you have generated the text file on a Windows system, you
might have to use `LINES TERMINATED BY '\r\n'' to read the file
properly, because Windows programs typically use two characters as a
line terminator. Some programs, such as `WordPad', might use `\r' as a
line terminator when writing files. To read such files, use `LINES
TERMINATED BY '\r''.
If all the lines you want to read in have a common prefix that you want
to ignore, you can use `LINES STARTING BY 'prefix_string'' to skip over
the prefix (and anything before it). If a line doesn't include the
in the middle of the line!
mysql> LOAD DATA INFILE '/tmp/test.txt'
-> INTO TABLE test LINES STARTING BY "xxx";
With this you can read in a file that contains something like:
And just get the data `("row",1)' and `("row",2)'.
The `IGNORE number LINES' option can be used to ignore lines at the
start of the file. For example, you can use `IGNORE 1 LINES' to skip
over an initial header line containing column names:
mysql> LOAD DATA INFILE '/tmp/test.txt'
-> INTO TABLE test IGNORE 1 LINES;
When you use `SELECT ... INTO OUTFILE' in tandem with `LOAD DATA
INFILE' to write data from a database into a file and then read the
file back into the database later, the field- and line-handling options
for both statements must match. Otherwise, `LOAD DATA INFILE' will not
interpret the contents of the file properly. Suppose that you use
`SELECT ... INTO OUTFILE' to write a file with fields delimited by
mysql> SELECT * INTO OUTFILE 'data.txt'
-> FIELDS TERMINATED BY ','
-> FROM table2;
To read the comma-delimited file back in, the correct statement would
mysql> LOAD DATA INFILE 'data.txt' INTO TABLE table2
-> FIELDS TERMINATED BY ',';
If instead you tried to read in the file with the statement shown here,
it wouldn't work because it instructs `LOAD DATA INFILE' to look for
tabs between fields:
mysql> LOAD DATA INFILE 'data.txt' INTO TABLE table2
-> FIELDS TERMINATED BY '\t';
The likely result is that each input line would be interpreted as a
`LOAD DATA INFILE' can be used to read files obtained from external
sources, too. For example, a file in dBASE format will have fields
separated by commas and enclosed within double quotes. If lines in the
file are terminated by newlines, the statement shown here illustrates
the field- and line-handling options you would use to load the file:
mysql> LOAD DATA INFILE 'data.txt' INTO TABLE TBL_NAME
-> FIELDS TERMINATED BY ',' ENCLOSED BY '"'
-> LINES TERMINATED BY '\n';
Any of the field- or line-handling options can specify an empty string
(`'''). If not empty, the `FIELDS [OPTIONALLY] ENCLOSED BY' and
`FIELDS ESCAPED BY' values must be a single character. The `FIELDS
TERMINATED BY', `LINES STARTING BY', and `LINES TERMINATED BY' values
can be more than one character. For example, to write lines that are
terminated by carriage return/linefeed pairs, or to read a file
containing such lines, specify a `LINES TERMINATED BY '\r\n'' clause.
To read a file containing jokes that are separated by lines consisting
of `%%', you can do this
mysql> CREATE TABLE jokes
-> (a INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
-> joke TEXT NOT NULL);
mysql> LOAD DATA INFILE '/tmp/jokes.txt' INTO TABLE jokes
-> FIELDS TERMINATED BY ''
-> LINES TERMINATED BY '\n%%\n' (joke);
`FIELDS [OPTIONALLY] ENCLOSED BY' controls quoting of fields. For
output (`SELECT ... INTO OUTFILE'), if you omit the word `OPTIONALLY',
all fields are enclosed by the `ENCLOSED BY' character. An example of
such output (using a comma as the field delimiter) is shown here:
"2","a string containing a , comma","102.20"
"3","a string containing a \" quote","102.20"
"4","a string containing a \", quote and comma","102.20"
If you specify `OPTIONALLY', the `ENCLOSED BY' character is used only
to enclose `CHAR' and `VARCHAR' fields:
2,"a string containing a , comma",102.20
3,"a string containing a \" quote",102.20
4,"a string containing a \", quote and comma",102.20
Note that occurrences of the `ENCLOSED BY' character within a field
value are escaped by prefixing them with the `ESCAPED BY' character.
Also note that if you specify an empty `ESCAPED BY' value, it is
possible to generate output that cannot be read properly by `LOAD DATA
INFILE'. For example, the preceding output just shown would appear as
follows if the escape character is empty. Observe that the second
field in the fourth line contains a comma following the quote, which
(erroneously) appears to terminate the field:
2,"a string containing a , comma",102.20
3,"a string containing a " quote",102.20
4,"a string containing a ", quote and comma",102.20
For input, the `ENCLOSED BY' character, if present, is stripped from
the ends of field values. (This is true whether or not `OPTIONALLY' is
specified; `OPTIONALLY' has no effect on input interpretation.)
Occurrences of the `ENCLOSED BY' character preceded by the `ESCAPED BY'
character are interpreted as part of the current field value.
If the field begins with the `ENCLOSED BY' character, instances of that
character are recognized as terminating a field value only if followed
by the field or line `TERMINATED BY' sequence. To avoid ambiguity,
occurrences of the `ENCLOSED BY' character within a field value can be
doubled and will be interpreted as a single instance of the character.
For example, if `ENCLOSED BY '"'' is specified, quotes are handled as
"The ""BIG"" boss" -> The "BIG" boss
The "BIG" boss -> The "BIG" boss
The ""BIG"" boss -> The ""BIG"" boss
`FIELDS ESCAPED BY' controls how to write or read special characters.
If the `FIELDS ESCAPED BY' character is not empty, it is used to prefix
the following characters on output:
* The `FIELDS ESCAPED BY' character
* The `FIELDS [OPTIONALLY] ENCLOSED BY' character
* The first character of the `FIELDS TERMINATED BY' and `LINES
TERMINATED BY' values
* ASCII `0' (what is actually written following the escape character
is ASCII `0', not a zero-valued byte)
If the `FIELDS ESCAPED BY' character is empty, no characters are
escaped and `NULL' is output as `NULL', not `\N'. It is probably not a
good idea to specify an empty escape character, particularly if field
values in your data contain any of the characters in the list just
For input, if the `FIELDS ESCAPED BY' character is not empty,
occurrences of that character are stripped and the following character
is taken literally as part of a field value. The exceptions are an
escaped `0' or `N' (for example, `\0' or `\N' if the escape character is
`\'). These sequences are interpreted as ASCII NUL (a zero-valued
byte) and `NULL'. The rules for `NULL' handling are described later in
For more information about `\'-escape syntax, see Literals.
In certain cases, field- and line-handling options interact:
* If `LINES TERMINATED BY' is an empty string and `FIELDS TERMINATED
BY' is non-empty, lines are also terminated with `FIELDS
* If the `FIELDS TERMINATED BY' and `FIELDS ENCLOSED BY' values are
both empty (`'''), a fixed-row (non-delimited) format is used.
With fixed-row format, no delimiters are used between fields (but
you can still have a line terminator). Instead, column values are
written and read using the "display" widths of the columns. For
example, if a column is declared as `INT(7)', values for the
column are written using seven-character fields. On input, values
for the column are obtained by reading seven characters.
`LINES TERMINATED BY' is still used to separate lines. If a line
doesn't contain all fields, the rest of the columns are set to
their default values. If you don't have a line terminator, you
should set this to `'''. In this case, the text file must contain
all fields for each row.
Fixed-row format also affects handling of `NULL' values, as
described later. Note that fixed-size format will not work if you
are using a multi-byte character set.
Handling of `NULL' values varies according to the `FIELDS' and `LINES'
options in use:
* For the default `FIELDS' and `LINES' values, `NULL' is written as
a field value of `\N' for output, and a field value of `\N' is
read as `NULL' for input (assuming that the `ESCAPED BY' character
* If `FIELDS ENCLOSED BY' is not empty, a field containing the
literal word `NULL' as its value is read as a `NULL' value. This
differs from the word `NULL' enclosed within `FIELDS ENCLOSED BY'
characters, which is read as the string `'NULL''.
* If `FIELDS ESCAPED BY' is empty, `NULL' is written as the word
* With fixed-row format (which happens when `FIELDS TERMINATED BY'
and `FIELDS ENCLOSED BY' are both empty), `NULL' is written as an
empty string. Note that this causes both `NULL' values and empty
strings in the table to be indistinguishable when written to the
file because they are both written as empty strings. If you need
to be able to tell the two apart when reading the file back in,
you should not use fixed-row format.
Some cases are not supported by `LOAD DATA INFILE':
* Fixed-size rows (`FIELDS TERMINATED BY' and `FIELDS ENCLOSED BY'
both empty) and `BLOB' or `TEXT' columns.
* If you specify one separator that is the same as or a prefix of
another, `LOAD DATA INFILE' won't be able to interpret the input
properly. For example, the following `FIELDS' clause would cause
FIELDS TERMINATED BY '"' ENCLOSED BY '"'
* If `FIELDS ESCAPED BY' is empty, a field value that contains an
occurrence of `FIELDS ENCLOSED BY' or `LINES TERMINATED BY'
followed by the `FIELDS TERMINATED BY' value will cause `LOAD DATA
INFILE' to stop reading a field or line too early. This happens
because `LOAD DATA INFILE' cannot properly determine where the
field or line value ends.
The following example loads all columns of the `persondata' table:
mysql> LOAD DATA INFILE 'persondata.txt' INTO TABLE persondata;
By default, when no column list is provided at the end of the `LOAD
DATA INFILE' statement, input lines are expected to contain a field for
each table column. If you want to load only some of a table's columns,
specify a column list:
mysql> LOAD DATA INFILE 'persondata.txt'
-> INTO TABLE persondata (col1,col2,...);
You must also specify a column list if the order of the fields in the
input file differs from the order of the columns in the table.
Otherwise, MySQL cannot tell how to match up input fields with table
If an input line has too many fields, the extra fields are ignored and
the number of warnings is incremented.
If an input line has too few fields, the table columns for which input
fields are missing are set to their default values. Default value
assignment is described in `CREATE TABLE' CREATE TABLE.
An empty field value is interpreted differently than if the field value
* For string types, the column is set to the empty string.
* For numeric types, the column is set to `0'.
* For date and time types, the column is set to the appropriate
"zero" value for the type. Date and time types.
These are the same values that result if you assign an empty string
explicitly to a string, numeric, or date or time type explicitly in an
`INSERT' or `UPDATE' statement.
`TIMESTAMP' columns are set to the current date and time only if there
is a `NULL' value for the column (that is, `\N'), or (for the first
`TIMESTAMP' column only) if the `TIMESTAMP' column is omitted from the
field list when a field list is specified.
`LOAD DATA INFILE' regards all input as strings, so you can't use
numeric values for `ENUM' or `SET' columns the way you can with
`INSERT' statements. All `ENUM' and `SET' values must be specified as
When the `LOAD DATA INFILE' statement finishes, it returns an
information string in the following format:
Records: 1 Deleted: 0 Skipped: 0 Warnings: 0
If you are using the C API, you can get information about the statement
by calling the `mysql_info()' function. `mysql_info()'
Warnings occur under the same circumstances as when values are inserted
via the `INSERT' statement ( `INSERT' INSERT.), except that `LOAD
DATA INFILE' also generates warnings when there are too few or too many
fields in the input row. The warnings are not stored anywhere; the
number of warnings can be used only as an indication of whether
everything went well.
From MySQL 4.1.1 on, you can use `SHOW WARNINGS' to get a list of the
first `max_error_count' warnings as information about what went wrong.
`SHOW WARNINGS' SHOW WARNINGS.
Before MySQL 4.1.1, only a warning count is available to indicate that
something went wrong. If you get warnings and want to know exactly why
you got them, one way to do this is to dump the table into another file
using `SELECT ... INTO OUTFILE' and compare the file to your original
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