如果参数是数字，我怎样才能让雪花中的 javascript 函数返回一个值，如果参数不是数字，我如何返回另一个值？

Question

My company is transitioning from an oracle database solution to snowflake data warehouse. I am converting our user defined oracle functions to snowflake user defined functions. One function we have in oracle will return a 1 if the passed value is numeric, and a 0 if the passed value is non-numeric.

To be more specific, I want to update a column (x_value) when the value column has a numeric value in it. For instance, if I have a field titled creditscore with values of 700, 599, 'no record' in rows, I need to update a field (xscore) with the numeric values and leave the non-numeric creditscore null in the xscore field.

I am new to javascript (well, not new exactly -- I did work with it all day today), and have had no luck. Here is the basic function:

CREATE OR REPLACE FUNCTION isnum(x variant)
RETURNS integer
LANGUAGE javascript
'
IF (isNan(x))
{
RETURN 1;
}
ELSE RETURN 0;
';

I have also tried typeof but get the same error, shown below:

SQL Error [1003] [42000]: SQL compilation error:
syntax error line 4 at position 0 unexpected ''

IF (isNan(x))
{
RETURN 1;
}
ELSE RETURN 0;

''.

Thank you for your assistance!

Answer 1

If it is Javascript then it is case sensitive.

if ( isNaN(x) ) {
  return 1;
} else {
  return 0;
}

Or you could always use a ternary operator:

return ( isNaN(x) ? 1 : 0 );

However, I have never used Snowflake before, so if it requires the JS to be formatted in a specific manner than I am unable to help with that (just the vanilla JS syntax itself).

Answer 2

You don't need a user defined function for this. You can use Snowflake's TRY_TO_NUMBER function.

create or replace table TEST1 (s string);

insert into TEST1 select ('Not a number');
insert into TEST1 select ('750');

select try_to_number(s) from TEST_IS_NUMBER;

Then you can insert from this select.