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* replace exit with assert in test_single_page * improve save_raw_single_page docs option * More grammar fixes * "Built from" link in new tab * fix mistype * Example of include in docs * add anchor to meeting form * Draft of translation helper * WIP on translation helper * Replace some fa docs content with machine translation * add normalize-en-markdown.sh * normalize some en markdown * normalize some en markdown * admonition support * normalize * normalize * normalize * support wide tables * normalize * normalize * normalize * normalize * normalize * normalize * normalize * normalize * normalize * normalize * normalize * normalize * normalize * lightly edited machine translation of introdpection.md * lightly edited machhine translation of lazy.md * WIP on translation utils * Normalize ru docs * Normalize other languages * some fixes * WIP on normalize/translate tools * add requirements.txt * [experimental] add es docs language as machine translated draft * remove duplicate script * Back to wider tab-stop (narrow renders not so well) * Links to nowhere check at least for English * use f string * More complete es translation
2.8 KiB
2.8 KiB
Diccionario
El Dictionary el motor muestra el Diccionario datos como una tabla ClickHouse.
Como ejemplo, considere un diccionario de products con la siguiente configuración:
<dictionaries>
<dictionary>
<name>products</name>
<source>
<odbc>
<table>products</table>
<connection_string>DSN=some-db-server</connection_string>
</odbc>
</source>
<lifetime>
<min>300</min>
<max>360</max>
</lifetime>
<layout>
<flat/>
</layout>
<structure>
<id>
<name>product_id</name>
</id>
<attribute>
<name>title</name>
<type>String</type>
<null_value></null_value>
</attribute>
</structure>
</dictionary>
</dictionaries>
Consultar los datos del diccionario:
SELECT
name,
type,
key,
attribute.names,
attribute.types,
bytes_allocated,
element_count,
source
FROM system.dictionaries
WHERE name = 'products'
┌─name─────┬─type─┬─key────┬─attribute.names─┬─attribute.types─┬─bytes_allocated─┬─element_count─┬─source──────────┐
│ products │ Flat │ UInt64 │ ['title'] │ ['String'] │ 23065376 │ 175032 │ ODBC: .products │
└──────────┴──────┴────────┴─────────────────┴─────────────────┴─────────────────┴───────────────┴─────────────────┘
Puede usar el dictGet* función para obtener los datos del diccionario en este formato.
Esta vista no es útil cuando necesita obtener datos sin procesar o cuando JOIN operación. Para estos casos, puede usar el Dictionary motor, que muestra los datos del diccionario en una tabla.
Sintaxis:
CREATE TABLE %table_name% (%fields%) engine = Dictionary(%dictionary_name%)`
Ejemplo de uso:
create table products (product_id UInt64, title String) Engine = Dictionary(products);
Ok
Echa un vistazo a lo que hay en la mesa.
select * from products limit 1;
┌────product_id─┬─title───────────┐
│ 152689 │ Some item │
└───────────────┴─────────────────┘