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LOAD DATA INFILE

Read rows from a text file into a table. This high-speed data loading command parses structured text files and inserts records, often much faster than INSERT statements.

Syntax

Description

LOAD DATA INFILE is for statement-based replication.

Reads rows from a text file into the designated table on the database at a very high speed. The file name must be given as a literal string.

Files are written to disk using the statement. You can then read the files back into a table using the LOAD DATA INFILE statement. The FIELDS and LINES clauses are the same in both statements and by default fields are expected to be terminated with tabs () and lines with newlines (). These clauses are optional, but if both are specified then the FIELDS clause must precede LINES.

Executing this statement activates INSERT .

One must have the privilege to be able to execute LOAD DATA INFILE. This is to ensure normal users cannot read system files. LOAD DATA LOCAL INFILE does not have this requirement.

If the system variable is set (by default it is not), the loaded file must be present in the specified directory.

Note that MariaDB's unit file restricts access to /home, /root, and /run/user by default. See .

LOAD DATA LOCAL INFILE

When you execute the LOAD DATA INFILE statement, MariaDB Server attempts to read the input file from its own file system. By contrast, when you execute the LOAD DATA LOCAL INFILE statement, the client attempts to read the input file from its file system, and it sends the contents of the input file to the MariaDB Server. This allows you to load files from the client's local file system into the database.

If you don't want to permit this operation (perhaps for security reasons), you can disable the LOAD DATA LOCAL INFILE statement on either the server or the client.

  • The LOAD DATA LOCAL INFILE statement can be disabled on the server by setting the system variable to 0.

  • The LOAD DATA LOCAL INFILE statement can be disabled on the client. If you are using , this can be done by unsetting the CLIENT_LOCAL_FILES capability flag with the function or by unsetting the MYSQL_OPT_LOCAL_INFILE option with function. If you are using a different client or client library, then see the documentation for your specific client or client library to determine how it handles the LOAD DATA LOCAL INFILE

If the LOAD DATA LOCAL INFILE statement is disabled by either the server or the client and if the user attempts to execute it, then the server will cause the statement to fail with the following error message:

Note that it is not entirely accurate to say that the MariaDB version does not support the command. It would be more accurate to say that the MariaDB configuration does not support the command. See for more information.

From , the error message is more accurate:

REPLACE and IGNORE

If you load data from a file into a table that already contains data and has a , you may encounter issues where the statement attempts to insert a row with a primary key that already exists. When this happens, the statement fails with Error 1064, protecting the data already on the table. If you want MariaDB to overwrite duplicates, use the REPLACE keyword.

The REPLACE keyword works like the statement. Here, the statement attempts to load the data from the file. If the row does not exist, it adds it to the table. If the row contains an existing primary key, it replaces the table data. That is, in the event of a conflict, it assumes the file contains the desired row.

This operation can cause a degradation in load speed by a factor of 20 or more if the part that has already been loaded is larger than the capacity of the . This happens because it causes a lot of turnaround in the buffer pool.

Use the IGNORE keyword when you want to skip any rows that contain a conflicting primary key. Here, the statement attempts to load the data from the file. If the row does not exist, it adds it to the table. If the row contains an existing primary key, it ignores the addition request and moves on to the next. That is, in the event of a conflict, it assumes the table contains the desired row.

IGNORE number {LINES|ROWS}

The IGNORE number LINES syntax can be used to ignore a number of rows from the beginning of the file. Most often this is needed when the file starts with one row that includes the column headings.

Character Sets

When the statement opens the file, it attempts to read the contents using the default character-set, as defined by the system variable.

In the cases where the file was written using a character-set other than the default, you can specify the character-set to use with the CHARACTER SET clause in the statement. It ignores character-sets specified by the statement and by the system variable. Setting the CHARACTER SET clause to a value of binary indicates "no conversion."

The statement interprets all fields in the file as having the same character-set, regardless of the column data type. To properly interpret file contents, you must ensure that it was written with the correct character-set. If you write a data file with or with the statement with the client, be sure to use the --default-character-set option, so that the output is written with the desired character-set.

When using mixed character sets, use the CHARACTER SET clause in both and LOAD DATA INFILE to ensure that MariaDB correctly interprets the escape sequences.

The system variable controls the interpretation of the filename. It is currently not possible to load data files that use the ucs2 character set.

Preprocessing Inputs

col_name_or_user_var can be a column name, or a user variable. In the case of a variable, the statement can be used to preprocess the value before loading into the table.

Priority and Concurrency

In storage engines that perform table-level locking (, and ), using the keyword, MariaDB delays insertions until no other clients are reading from the table. Alternatively, when using the storage engine, you can use the keyword to perform concurrent insertion.

The LOW_PRIORITY and CONCURRENT keywords are mutually exclusive. They cannot be used in the same statement.

Progress Reporting

The LOAD DATA INFILE statement supports . You may find this useful when dealing with long-running operations. Using another client you can issue a query to check the progress of the data load.

Using mariadb-import

MariaDB ships with a separate utility for loading data from files: . It operates by sending LOAD DATA INFILE statements to the server.

MariaDB ships with a separate utility for loading data from files: mysqlimport . It operates by sending LOAD DATA INFILE statements to the server.

Using you can compress the file using the --compress option, to get better performance over slow networks, providing both the client and server support the compressed protocol. Use the --local option to load from the local file system.

Indexing

In cases where the storage engine supports statements ( and ), the LOAD DATA INFILE statement automatically disables indexes during the execution.

Examples

You have a file with this content (note the separator is ',', not tab, which is the default):

Another example, given the following data (the separator is a tab):

The value of the first column is doubled before loading:

See Also

This page is licensed: GPLv2, originally from

LOAD DATA [LOW_PRIORITY | CONCURRENT] [LOCAL] INFILE 'file_name'
    [REPLACE | IGNORE]
    INTO TABLE tbl_name
    [CHARACTER SET charset_name]
    [{FIELDS | COLUMNS}
        [TERMINATED BY 'string']
        [[OPTIONALLY] ENCLOSED BY 'CHAR']
        [ESCAPED BY 'CHAR']
    ]
    [LINES
        [STARTING BY 'string']
        [TERMINATED BY 'string']
    ]
    [IGNORE number {LINES|ROWS}]
    [(col_name_or_user_var,...)]
    [SET col_name = expr,...]
statement.
  • The LOAD DATA LOCAL INFILE strict modes like STRICT_TRANS_TABLES are disabled with keyword "local". (MDEV-11235)

  • unsafe
    SELECT INTO OUTFILE
    triggers
    FILE
    secure_file_priv
    systemd
    Configuring access to home directories
    local_infile
    MDEV-20500
    primary key
    REPLACE
    InnoDB Buffer Pool
    character_set_database
    SET NAMES
    character_set_client
    mariadb-dump -T
    SELECT INTO OUTFILE
    mariadb
    SELECT INTO OUTFILE
    character_set_filesystem
    SET
    MyISAM
    MEMORY
    MERGE
    LOW_PRIORITY
    MyISAM
    CONCURRENT
    SHOW PROCESSLIST
    mariadb-import
    mariadb-import
    ALTER TABLE... DISABLE KEYS
    MyISAM
    Aria
    How to quickly insert data into MariaDB
    Character Sets and Collations
    SELECT ... INTO OUTFILE
    mariadb-import
    fill_help_tables.sql
    The used command is not allowed with this MariaDB version
    The used command is not allowed because the MariaDB server or client 
      has disabled the local infile capability
    2,2
    3,3
    4,4
    5,5
    6,8
    CREATE TABLE t1 (a INT, b INT, c INT, d INT, PRIMARY KEY (a));
    LOAD DATA LOCAL INFILE 
     '/tmp/loaddata7.dat' INTO TABLE t1 FIELDS TERMINATED BY ',' (a,b) SET c=a+b;
    SELECT * FROM t1;
    +------+------+------+
    | a    | b    | c    |
    +------+------+------+
    |    2 |    2 |    4 |
    |    3 |    3 |    6 |
    |    4 |    4 |    8 |
    |    5 |    5 |   10 |
    |    6 |    8 |   14 |
    +------+------+------+
    1       a
    2       b
    LOAD DATA INFILE 'ld.txt' INTO TABLE ld (@i,v) SET i=@i*2;
    
    SELECT * FROM ld;
    +------+------+
    | i    | v    |
    +------+------+
    |    2 | a    |
    |    4 | b    |
    +------+------+
    MariaDB Connector/C
    mysql_real_connect
    mysql_optionsv
    progress reporting
    MariaDB 10.5.2