SHOW EXTERNAL FUNCTION

语法

SHOW EXTERNAL FUNCTION function_name [ ( parameter_type[, ...] ) ]

描述

输出注册在function manager中的external function函数信息。 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.

例子

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:

show external function example.default.format(double, integer);

                                                             External Function                                                              | Argument Types
--------------------------------------------------------------------------------------------------------------------------------------------+-----------------
 External FUNCTION example.default.format (                                                                                                 | double, integer
    k double,                                                                                                                               |
    h integer                                                                                                                               |
 )                                                                                                                                          |
 RETURNS varchar                                                                                                                            |
                                                                                                                                            |
 COMMENT 'format the number ''num'' to a format like''#,###,###.##'', rounded to ''lo'' decimal places, and returns the result as a string' |
 DETERMINISTIC                                                                                                                              |
 RETURNS NULL ON NULL INPUT                                                                                                                 |
 EXTERNAL

显示所有函数名称为 example.default.format 的external function函数信息:

show external function example.default.format;

                                                             External Function                                                              | Argument Types
--------------------------------------------------------------------------------------------------------------------------------------------+-----------------
External FUNCTION example.default.format (                                                                                                 | double, integer
  k double,                                                                                                                               |
  h integer                                                                                                                               |
)                                                                                                                                          |
RETURNS varchar                                                                                                                            |
                                                                                                                                          |
COMMENT 'format the number ''num'' to a format like''#,###,###.##'', rounded to ''lo'' decimal places, and returns the result as a string' |
DETERMINISTIC                                                                                                                              |
RETURNS NULL ON NULL INPUT                                                                                                                 |
EXTERNAL  
External FUNCTION example.default.format (                                                                                                | real, integer
  k real,                                                                                                                              |
  h integer                                                                                                                               |
)                                                                                                                                          |
RETURNS varchar                                                                                                                            |
                                                                                                                                          |
COMMENT 'format the number ''num'' to a format like''#,###,###.##'', rounded to ''lo'' decimal places, and returns the result as a string' |
DETERMINISTIC                                                                                                                              |
RETURNS NULL ON NULL INPUT                                                                                                                 |
EXTERNAL

参考信息

Function Namespace Managers