mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-10-17 22:10:54 +00:00
23 lines
879 B
Markdown
23 lines
879 B
Markdown
|
---
|
||
|
|
machine_translated: true
|
||
|
|
machine_translated_rev: b111334d6614a02564cf32f379679e9ff970d9b1
|
||
|
|
toc_folder_title: "\u5B57\u5178"
|
||
|
|
toc_priority: 35
|
||
|
|
toc_title: "\u5BFC\u8A00"
|
||
|
|
---
|
||
|
|
|
||
|
|
# 字典 {#dictionaries}
|
||
|
|
|
||
|
|
字典是一个映射 (`key -> attributes`）这是方便各种类型的参考清单。
|
||
|
|
|
||
|
|
ClickHouse支持使用可用于查询的字典的特殊功能。 这是更容易和更有效地使用字典与功能比 `JOIN` 与参考表。
|
||
|
|
|
||
|
|
[NULL](../syntax.md#null) 值不能存储在字典中。
|
||
|
|
|
||
|
|
ClickHouse支持:
|
||
|
|
|
||
|
|
- [内置字典](internal_dicts.md#internal_dicts) 具有特定的 [功能集](../../sql_reference/functions/ym_dict_functions.md).
|
||
|
|
- [插件（外部）字典](external_dictionaries/external_dicts.md) 用一个 [职能净额](../../sql_reference/functions/ext_dict_functions.md).
|
||
|
|
|
||
|
|
[原始文章](https://clickhouse.tech/docs/en/query_language/dicts/) <!--hide-->
|