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3.0 KiB
mysql
Permitir SELECT consultas que se realizarán en los datos que se almacenan en un servidor MySQL remoto.
mysql('host:port', 'database', 'table', 'user', 'password'[, replace_query, 'on_duplicate_clause']);
Parámetros
-
host:port— Dirección del servidor MySQL. -
database— Nombre de base de datos remota. -
table— Nombre de la tabla remota. -
user— Usuario de MySQL. -
password— Contraseña de usuario. -
replace_query— Bandera que convierteINSERT INTOConsultas aREPLACE INTO. Sireplace_query=1, la consulta se reemplaza. -
on_duplicate_clause— ElON DUPLICATE KEY on_duplicate_clauseexpresión que se añade a laINSERTconsulta.Example: `INSERT INTO t (c1,c2) VALUES ('a', 2) ON DUPLICATE KEY UPDATE c2 = c2 + 1`, where `on_duplicate_clause` is `UPDATE c2 = c2 + 1`. See the MySQL documentation to find which `on_duplicate_clause` you can use with the `ON DUPLICATE KEY` clause. To specify `on_duplicate_clause` you need to pass `0` to the `replace_query` parameter. If you simultaneously pass `replace_query = 1` and `on_duplicate_clause`, ClickHouse generates an exception.
Simple WHERE cláusulas tales como =, !=, >, >=, <, <= se ejecutan actualmente 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.
Valor devuelto
Un objeto de tabla con las mismas columnas que la tabla MySQL original.
Ejemplo de uso
Tabla en MySQL:
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)
Selección de datos de ClickHouse:
SELECT * FROM mysql('localhost:3306', 'test', 'test', 'bayonet', '123')
┌─int_id─┬─int_nullable─┬─float─┬─float_nullable─┐
│ 1 │ ᴺᵁᴸᴸ │ 2 │ ᴺᵁᴸᴸ │
└────────┴──────────────┴───────┴────────────────┘