66 lines
5.2 KiB
Markdown
66 lines
5.2 KiB
Markdown
# SHOW EXTERNAL FUNCTION
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## 语法
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``` sql
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SHOW EXTERNAL FUNCTION function_name [ ( parameter_type[, ...] ) ]
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```
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## 描述
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输出注册在`function manager`中的`external function`函数信息。
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如果指定输入参数，则输出精准匹配输入类型的 `function_name` 的函数信息.
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## 例子
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例如我们需要显示函数签名为 `example.default.format(double, integer)`的`external function`函数信息:
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``` sql
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show external function example.default.format(double, integer);
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```
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``` sql
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External Function | Argument Types
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--------------------------------------------------------------------------------------------------------------------------------------------+-----------------
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External FUNCTION example.default.format ( | double, integer
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k double, |
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h integer |
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) |
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RETURNS varchar |
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COMMENT 'format the number ''num'' to a format like''#,###,###.##'', rounded to ''lo'' decimal places, and returns the result as a string' |
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DETERMINISTIC |
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RETURNS NULL ON NULL INPUT |
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EXTERNAL
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```
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显示所有函数名称为 `example.default.format` 的`external function`函数信息:
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``` sql
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show external function example.default.format;
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```
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``` sql
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External Function | Argument Types
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--------------------------------------------------------------------------------------------------------------------------------------------+-----------------
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External FUNCTION example.default.format ( | double, integer
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k double, |
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h integer |
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) |
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RETURNS varchar |
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COMMENT 'format the number ''num'' to a format like''#,###,###.##'', rounded to ''lo'' decimal places, and returns the result as a string' |
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DETERMINISTIC |
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RETURNS NULL ON NULL INPUT |
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EXTERNAL
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External FUNCTION example.default.format ( | real, integer
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k real, |
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h integer |
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) |
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RETURNS varchar |
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COMMENT 'format the number ''num'' to a format like''#,###,###.##'', rounded to ''lo'' decimal places, and returns the result as a string' |
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DETERMINISTIC |
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RETURNS NULL ON NULL INPUT |
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EXTERNAL
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```
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## 参考信息
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[Function Namespace Managers](../admin/function-namespace-managers.md) |