mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-18 13:42:02 +00:00
790704d081
* Simplify 404 page * add es array_functions.md * restore some old manual anchors * update sitemaps * trigger checks * restore more old manual anchors * refactor test.md + temporary disable failure again * fix mistype
129 lines
3.6 KiB
Markdown
129 lines
3.6 KiB
Markdown
# 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 {#creating-a-database}
|
|
|
|
``` sql
|
|
CREATE DATABASE [IF NOT EXISTS] db_name [ON CLUSTER cluster]
|
|
ENGINE = MySQL('host:port', 'database', 'user', 'password')
|
|
```
|
|
|
|
**Engine Parameters**
|
|
|
|
- `host:port` — MySQL server address.
|
|
- `database` — Remote database name.
|
|
- `user` — MySQL user.
|
|
- `password` — User password.
|
|
|
|
## Data Types Support {#data_types-support}
|
|
|
|
| MySQL | ClickHouse |
|
|
|----------------------------------|---------------------------------------------|
|
|
| UNSIGNED TINYINT | [UInt8](../data_types/int_uint.md) |
|
|
| TINYINT | [Int8](../data_types/int_uint.md) |
|
|
| UNSIGNED SMALLINT | [UInt16](../data_types/int_uint.md) |
|
|
| SMALLINT | [Int16](../data_types/int_uint.md) |
|
|
| UNSIGNED INT, UNSIGNED MEDIUMINT | [UInt32](../data_types/int_uint.md) |
|
|
| INT, MEDIUMINT | [Int32](../data_types/int_uint.md) |
|
|
| UNSIGNED BIGINT | [UInt64](../data_types/int_uint.md) |
|
|
| BIGINT | [Int64](../data_types/int_uint.md) |
|
|
| FLOAT | [Float32](../data_types/float.md) |
|
|
| DOUBLE | [Float64](../data_types/float.md) |
|
|
| DATE | [Date](../data_types/date.md) |
|
|
| DATETIME, TIMESTAMP | [DateTime](../data_types/datetime.md) |
|
|
| BINARY | [FixedString](../data_types/fixedstring.md) |
|
|
|
|
All other MySQL data types are converted into [String](../data_types/string.md).
|
|
|
|
[Nullable](../data_types/nullable.md) is supported.
|
|
|
|
## Examples of Use {#examples-of-use}
|
|
|
|
Table in MySQL:
|
|
|
|
``` text
|
|
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:
|
|
|
|
``` sql
|
|
CREATE DATABASE mysql_db ENGINE = MySQL('localhost:3306', 'test', 'my_user', 'user_password')
|
|
```
|
|
|
|
``` sql
|
|
SHOW DATABASES
|
|
```
|
|
|
|
``` text
|
|
┌─name─────┐
|
|
│ default │
|
|
│ mysql_db │
|
|
│ system │
|
|
└──────────┘
|
|
```
|
|
|
|
``` sql
|
|
SHOW TABLES FROM mysql_db
|
|
```
|
|
|
|
``` text
|
|
┌─name─────────┐
|
|
│ mysql_table │
|
|
└──────────────┘
|
|
```
|
|
|
|
``` sql
|
|
SELECT * FROM mysql_db.mysql_table
|
|
```
|
|
|
|
``` text
|
|
┌─int_id─┬─value─┐
|
|
│ 1 │ 2 │
|
|
└────────┴───────┘
|
|
```
|
|
|
|
``` sql
|
|
INSERT INTO mysql_db.mysql_table VALUES (3,4)
|
|
```
|
|
|
|
``` sql
|
|
SELECT * FROM mysql_db.mysql_table
|
|
```
|
|
|
|
``` text
|
|
┌─int_id─┬─value─┐
|
|
│ 1 │ 2 │
|
|
│ 3 │ 4 │
|
|
└────────┴───────┘
|
|
```
|
|
|
|
[Original article](https://clickhouse.tech/docs/en/database_engines/mysql/) <!--hide-->
|