DESCRIBE FUNCTION

描述指定的用户定义函数 (UDF) 或外部函数,包括签名(如实参)、返回值、语言和正文(如定义)。

DESCRIBE 可以缩写为 DESC。

另请参阅:

DROP FUNCTIONALTER FUNCTIONCREATE FUNCTIONSHOW USER FUNCTIONSSHOW EXTERNAL FUNCTIONS

语法

DESC[RIBE] FUNCTION <name> ( [ <arg_data_type> ] [ , ... ] )
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参数

name

指定要描述的函数的标识符。如果标识符包含空格或特殊字符,则整个字符串必须放在双引号内。放在双引号内的标识符也区分大小写。

arg_data_type [ , ... ]

指定函数的实参(如果有)的数据类型。实参数据类型是必需的,因为函数支持名称重载(即同一架构中的两个函数可以具有相同的名称),并且实参数据类型用于标识函数。

使用说明

  • To post-process the output of this command, you can use the pipe operator (->>) or the RESULT_SCAN function. Both constructs treat the output as a result set that you can query.

    For example, you can use the pipe operator or RESULT_SCAN function to select specific columns from the SHOW command output or filter the rows.

    When you refer to the output columns, use double-quoted identifiers for the column names. For example, to select the output column type, specify SELECT "type".

    You must use double-quoted identifiers because the output column names for SHOW commands are in lowercase. The double quotes ensure that the column names in the SELECT list or WHERE clause match the column names in the SHOW command output that was scanned.

示例

此示例演示了 DESCRIBE FUNCTION 命令:

DESC FUNCTION multiply(number, number);

-----------+----------------------------------+
 property  |              value               |
-----------+----------------------------------+
 signature | (a NUMBER(38,0), b NUMBER(38,0)) |
 returns   | NUMBER(38,0)                     |
 language  | SQL                              |
 body      | a * b                            |
-----------+----------------------------------+
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语言: 中文