MySQL Interface

ClickHouse supports MySQL wire protocol. It can be enabled by mysql_port setting in configuration file:

  1. <mysql_port>9004</mysql_port>

Example of connecting using command-line tool mysql:

  1. $ mysql --protocol tcp -u default -P 9004

Output if a connection succeeded:

  1. Welcome to the MySQL monitor.  Commands end with ; or \g.
  2. Your MySQL connection id is 4
  3. Server version: 20.2.1.1-ClickHouse
  5. Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
  7. Oracle is a registered trademark of Oracle Corporation and/or its
  8. affiliates. Other names may be trademarks of their respective
  9. owners.
  11. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
  13. mysql>

For compatibility with all MySQL clients, it is recommended to specify user password with double SHA1 in configuration file.
If user password is specified using SHA256, some clients won’t be able to authenticate (mysqljs and old versions of command-line tool mysql).

Restrictions:

  • prepared queries are not supported

  • some data types are sent as strings

To cancel a long query use KILL QUERY connection_id statement (it is replaced with KILL QUERY WHERE query_id = connection_id while proceeding). For example:

  1. $ mysql --protocol tcp -h mysql_server -P 9004 default -u default --password=123 -e "KILL QUERY 123456;"