在函数调用中声明日期和空值

Question

当我调用函数时，例如

SELECT  * FROM TABLE(FN_ABC(NULL::DATE , '2022-04-07'::DATE ))

Snowflake 强制我将传递给数据类型（例如 DATE）的参数绑定到上述所有 NULL。

有没有办法避免绑定它们？我已经在我的函数中将它们声明为 DATES

即不带数据类型直接调用它

SELECT  * FROM TABLE(FN_ABC(NULL, '2022-04-07'))

原因是这些参数是作为 NULL 或 2022-04-07 从网页传递的

谢谢

Answer 1

你的 sql 不是两个日期，它是一个未定义的类型，和一个 string/text/varchar.

select
    null as a
    ,'2022-04-07' as b
    ,system$typeof(a) as t_a
    ,system$typeof(b) as t_b
    ,a::date as d_a
    ,b::date as d_b
    ,system$typeof(d_a) as t_da
    ,system$typeof(d_b) as t_db

A	B	T_A	T_B	D_A	D_B	T_DA	T_DB
null	2022-04-07	NULL[LOB]	VARCHAR(10)[LOB]	null	2022-04-07	DATE[SB4]	DATE[SB4]

因此使用这些值会给您带来错误：

001044 (42P13): SQL compilation error: error line 1 at position 21

Invalid argument types for function 'FN_ABC': (NULL, VARCHAR(10))

但是如果你已经有DATE个值，就没有问题了：

with data as (
  select 
    null as a
    ,'2022-04-07' as b
    ,system$typeof(a) as t_a
    ,system$typeof(b) as t_b
    ,a::date as d_a
    ,b::date as d_b
     ,system$typeof(d_a) as t_da
    ,system$typeof(d_b) as t_db
  )
SELECT 
    f.*
FROM data as d
,table(fn_abc(d.d_a, d.d_b)) f;

运行，很好

X	Y
null	2022-04-07

在函数调用中声明日期和空值

Declaring Dates and Nulls in function calls

function

parameter-passing

snowflake-cloud-data-platform