MySQL

Allows to connect to databases on a remote MySQL server and perform INSERT and SELECT queries to exchange data between ClickHouse and MySQL.

The MySQL database engine translate queries to the MySQL server so you can perform operations such as SHOW TABLES or SHOW CREATE TABLE.

You cannot perform the following queries:

• RENAME
• CREATE TABLE
• ALTER

Creating a Database

CREATE DATABASE [IF NOT EXISTS] db_name [ON CLUSTER cluster]
ENGINE = MySQL('host:port', ['database' | database], 'user', 'password')

Engine Parameters

• host:port — MySQL server address.
• database — Remote database name.
• user — MySQL user.
• password — User password.

Data Types Support

All other MySQL data types are converted into String.

Nullable is supported.

Examples of Use

Table in MySQL:

mysql> USE test;
Database changed
mysql> CREATE TABLE `mysql_table` (
    ->   `int_id` INT NOT NULL AUTO_INCREMENT,
    ->   `float` FLOAT NOT NULL,
    ->   PRIMARY KEY (`int_id`));
Query OK, 0 rows affected (0,09 sec)
mysql> insert into mysql_table (`int_id`, `float`) VALUES (1,2);
Query OK, 1 row affected (0,00 sec)
mysql> select * from mysql_table;
+--------+-------+
| int_id | value |
+--------+-------+
|      1 |     2 |
+--------+-------+
1 row in set (0,00 sec)

Database in ClickHouse, exchanging data with the MySQL server:

CREATE DATABASE mysql_db ENGINE = MySQL('localhost:3306', 'test', 'my_user', 'user_password')

SHOW DATABASES

┌─name─────┐
│ default  │
│ mysql_db │
│ system   │
└──────────┘

SHOW TABLES FROM mysql_db

┌─name─────────┐
│  mysql_table │
└──────────────┘

SELECT * FROM mysql_db.mysql_table

┌─int_id─┬─value─┐
│      1 │     2 │
└────────┴───────┘

INSERT INTO mysql_db.mysql_table VALUES (3,4)

SELECT * FROM mysql_db.mysql_table

┌─int_id─┬─value─┐
│      1 │     2 │
│      3 │     4 │
└────────┴───────┘