mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-09-30 05:30:51 +00:00
cd14f9ebcb
* split up select.md * array-join.md basic refactoring * distinct.md basic refactoring * format.md basic refactoring * from.md basic refactoring * group-by.md basic refactoring * having.md basic refactoring * additional index.md refactoring * into-outfile.md basic refactoring * join.md basic refactoring * limit.md basic refactoring * limit-by.md basic refactoring * order-by.md basic refactoring * prewhere.md basic refactoring * adjust operators/index.md links * adjust sample.md links * adjust more links * adjust operatots links * fix some links * adjust aggregate function article titles * basic refactor of remaining select clauses * absolute paths in make_links.sh * run make_links.sh * remove old select.md locations * translate docs/es * translate docs/fr * translate docs/fa * remove old operators.md location * change operators.md links * adjust links in docs/es * adjust links in docs/es * minor texts adjustments * wip * update machine translations to use new links * fix changelog * es build fixes * get rid of some select.md links * temporary adjust ru links * temporary adjust more ru links * improve curly brace handling * adjust ru as well * fa build fix * ru link fixes * zh link fixes * temporary disable part of anchor checks
106 lines
4.0 KiB
Markdown
106 lines
4.0 KiB
Markdown
---
|
||
machine_translated: true
|
||
machine_translated_rev: 72537a2d527c63c07aa5d2361a8829f3895cf2bd
|
||
toc_priority: 33
|
||
toc_title: MySQL
|
||
---
|
||
|
||
# Mysql {#mysql}
|
||
|
||
El motor MySQL le permite realizar `SELECT` consultas sobre datos almacenados en un servidor MySQL remoto.
|
||
|
||
## Creación de una tabla {#creating-a-table}
|
||
|
||
``` sql
|
||
CREATE TABLE [IF NOT EXISTS] [db.]table_name [ON CLUSTER cluster]
|
||
(
|
||
name1 [type1] [DEFAULT|MATERIALIZED|ALIAS expr1] [TTL expr1],
|
||
name2 [type2] [DEFAULT|MATERIALIZED|ALIAS expr2] [TTL expr2],
|
||
...
|
||
) ENGINE = MySQL('host:port', 'database', 'table', 'user', 'password'[, replace_query, 'on_duplicate_clause']);
|
||
```
|
||
|
||
Vea una descripción detallada del [CREATE TABLE](../../../sql-reference/statements/create.md#create-table-query) consulta.
|
||
|
||
La estructura de la tabla puede diferir de la estructura de la tabla MySQL original:
|
||
|
||
- Los nombres de columna deben ser los mismos que en la tabla MySQL original, pero puede usar solo algunas de estas columnas y en cualquier orden.
|
||
- Los tipos de columna pueden diferir de los de la tabla MySQL original. ClickHouse intenta [elenco](../../../sql-reference/functions/type-conversion-functions.md#type_conversion_function-cast) valores a los tipos de datos ClickHouse.
|
||
|
||
**Parámetros del motor**
|
||
|
||
- `host:port` — MySQL server address.
|
||
|
||
- `database` — Remote database name.
|
||
|
||
- `table` — Remote table name.
|
||
|
||
- `user` — MySQL user.
|
||
|
||
- `password` — User password.
|
||
|
||
- `replace_query` — Flag that converts `INSERT INTO` consultas a `REPLACE INTO`. Si `replace_query=1`, la consulta se sustituye.
|
||
|
||
- `on_duplicate_clause` — The `ON DUPLICATE KEY on_duplicate_clause` expresión que se añade a la `INSERT` consulta.
|
||
|
||
Ejemplo: `INSERT INTO t (c1,c2) VALUES ('a', 2) ON DUPLICATE KEY UPDATE c2 = c2 + 1`, donde `on_duplicate_clause` ser `UPDATE c2 = c2 + 1`. Ver el [Documentación de MySQL](https://dev.mysql.com/doc/refman/8.0/en/insert-on-duplicate.html) para encontrar qué `on_duplicate_clause` se puede utilizar con el `ON DUPLICATE KEY` clausula.
|
||
|
||
Especificar `on_duplicate_clause` tienes que pasar `0` a la `replace_query` parámetro. Si pasa simultáneamente `replace_query = 1` y `on_duplicate_clause`, ClickHouse genera una excepción.
|
||
|
||
Simple `WHERE` cláusulas tales como `=, !=, >, >=, <, <=` se ejecutan en el servidor MySQL.
|
||
|
||
El resto de las condiciones y el `LIMIT` La restricción de muestreo se ejecuta en ClickHouse solo después de que finalice la consulta a MySQL.
|
||
|
||
## Ejemplo de uso {#usage-example}
|
||
|
||
Tabla en MySQL:
|
||
|
||
``` text
|
||
mysql> CREATE TABLE `test`.`test` (
|
||
-> `int_id` INT NOT NULL AUTO_INCREMENT,
|
||
-> `int_nullable` INT NULL DEFAULT NULL,
|
||
-> `float` FLOAT NOT NULL,
|
||
-> `float_nullable` FLOAT NULL DEFAULT NULL,
|
||
-> PRIMARY KEY (`int_id`));
|
||
Query OK, 0 rows affected (0,09 sec)
|
||
|
||
mysql> insert into test (`int_id`, `float`) VALUES (1,2);
|
||
Query OK, 1 row affected (0,00 sec)
|
||
|
||
mysql> select * from test;
|
||
+------+----------+-----+----------+
|
||
| int_id | int_nullable | float | float_nullable |
|
||
+------+----------+-----+----------+
|
||
| 1 | NULL | 2 | NULL |
|
||
+------+----------+-----+----------+
|
||
1 row in set (0,00 sec)
|
||
```
|
||
|
||
Tabla en ClickHouse, recuperando datos de la tabla MySQL creada anteriormente:
|
||
|
||
``` sql
|
||
CREATE TABLE mysql_table
|
||
(
|
||
`float_nullable` Nullable(Float32),
|
||
`int_id` Int32
|
||
)
|
||
ENGINE = MySQL('localhost:3306', 'test', 'test', 'bayonet', '123')
|
||
```
|
||
|
||
``` sql
|
||
SELECT * FROM mysql_table
|
||
```
|
||
|
||
``` text
|
||
┌─float_nullable─┬─int_id─┐
|
||
│ ᴺᵁᴸᴸ │ 1 │
|
||
└────────────────┴────────┘
|
||
```
|
||
|
||
## Ver también {#see-also}
|
||
|
||
- [El ‘mysql’ función de la tabla](../../../sql-reference/table-functions/mysql.md)
|
||
- [Uso de MySQL como fuente de diccionario externo](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-sources.md#dicts-external_dicts_dict_sources-mysql)
|
||
|
||
[Artículo Original](https://clickhouse.tech/docs/en/operations/table_engines/mysql/) <!--hide-->
|