mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-16 19:32:07 +00:00
d91c97d15d
* Replace underscores with hyphens * remove temporary code * fix style check * fix collapse
4.0 KiB
4.0 KiB
toc_priority | toc_title |
---|---|
30 | MySQL |
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
MySQL | ClickHouse |
---|---|
UNSIGNED TINYINT | UInt8 |
TINYINT | Int8 |
UNSIGNED SMALLINT | UInt16 |
SMALLINT | Int16 |
UNSIGNED INT, UNSIGNED MEDIUMINT | UInt32 |
INT, MEDIUMINT | Int32 |
UNSIGNED BIGINT | UInt64 |
BIGINT | Int64 |
FLOAT | Float32 |
DOUBLE | Float64 |
DATE | Date |
DATETIME, TIMESTAMP | DateTime |
BINARY | FixedString |
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 │
└────────┴───────┘