ClickHouse/docs/zh/sql-reference/functions/ext-dict-functions.md
Ivan Blinkov d91c97d15d
[docs] replace underscores with hyphens (#10606)
* Replace underscores with hyphens

* remove temporary code

* fix style check

* fix collapse
2020-04-30 21:19:18 +03:00

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# 字典函数 {#zi-dian-han-shu}
有关连接和配置外部词典的信息,请参阅[外部词典](../../sql-reference/functions/ext-dict-functions.md)。
## dictGetUInt8,dictGetUInt16,dictGetUInt32,dictGetUInt64 {#dictgetuint8-dictgetuint16-dictgetuint32-dictgetuint64}
## dictGetInt8,dictGetInt16,dictGetInt32,dictGetInt64 {#dictgetint8-dictgetint16-dictgetint32-dictgetint64}
## dictGetFloat32,dictGetFloat64 {#dictgetfloat32-dictgetfloat64}
## dictGetDate,dictGetDateTime {#dictgetdate-dictgetdatetime}
## dictgetuid {#dictgetuuid}
## dictGetString {#dictgetstring}
`dictGetT('dict_name', 'attr_name', id)`
- 使用id键获取dict\_name字典中attr\_name属性的值。`dict_name`和`attr_name`是常量字符串。`id`必须是UInt64。
如果字典中没有`id`键,则返回字典描述中指定的默认值。
## dictGetTOrDefault {#ext_dict_functions-dictgettordefault}
`dictGetTOrDefault('dict_name', 'attr_name', id, default)`
与`dictGetT`函数相同,但默认值取自函数的最后一个参数。
## dictIsIn {#dictisin}
`dictIsIn ('dict_name', child_id, ancestor_id)`
- 对于dict\_name分层字典查找child\_id键是否位于ancestor\_id或匹配ancestor\_id。返回UInt8。
## 独裁主义 {#dictgethierarchy}
`dictGetHierarchy('dict_name', id)`
- 对于dict\_name分层字典返回从id开始并沿父元素链继续的字典键数组。返回ArrayUInt64
## dictHas {#dicthas}
`dictHas('dict_name', id)`
- 检查字典是否存在指定的`id`。如果不存在则返回0;如果存在则返回1。
[来源文章](https://clickhouse.tech/docs/en/query_language/functions/ext_dict_functions/) <!--hide-->