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CSV Overview

The CSV Storage Engine stores data in comma-separated values format text files, making it easy to exchange data with other applications.

The CSV Storage Engine can read and append to files stored in CSV (comma-separated-values) format.

The CSV storage engine and logging to tables

The CSV storage engine is the default storage engine when using logging of SQL queries to tables.

CSV Storage Engine files

When you create a table using the CSV storage engine, three files are created:

  • <table_name>.frm

  • <table_name>.CSV

  • <table_name>.CSM

The .frm file is the table format file.

The .CSV file is a plain text file. Data you enter into the table is stored as plain text in comma-separated-values format.

The .CSM file stores metadata about the table such as the state and the number of rows in the table.

Limitations

  • CSV tables do not support indexing.

  • CSV tables cannot be partitioned.

  • Columns in CSV tables must be declared as NOT NULL.

  • No .

Examples

Forgetting to add NOT NULL:

Creating, inserting and selecting:

Viewing in a text editor:

See Also

This page is licensed: CC BY-SA / Gnu FDL

mysqld --log-output=table
The original CSV-format does not enable IETF-compatible parsing of embedded quote and comma characters. From , it is possible to do so by setting the IETF_QUOTES option when creating a table.
transactions
Checking and Repairing CSV Tables
CREATE TABLE csv_test (x INT, y DATE, z CHAR(10)) ENGINE=CSV;
ERROR 1178 (42000): The storage engine for the table doesn't support nullable columns
CREATE TABLE csv_test (
  x INT NOT NULL, y DATE NOT NULL, z CHAR(10) NOT NULL
  ) ENGINE=CSV;
INSERT INTO csv_test VALUES
    (1,CURDATE(),'one'),
    (2,CURDATE(),'two'),
    (3,CURDATE(),'three');
SELECT * FROM csv_test;
+---+------------+-------+
| x | y          | z     |
+---+------------+-------+
| 1 | 2011-11-16 | one   |
| 2 | 2011-11-16 | two   |
| 3 | 2011-11-16 | three |
+---+------------+-------+
$ cat csv_test.CSV
1,"2011-11-16","one"
2,"2011-11-16","two"
3,"2011-11-16","three"
MariaDB 10.1.8