当我尝试 select 行，其中列的修剪值不是 null 时，它仍然返回具有 null 值的行（雪花）

Question

SELECT Client_id, first_name, mobile_number 
FROM client_table 
WHERE trim(mobile_number) IS NOT NULL

Answer 1

Trim does not make the value as NULL but instead an empty string

 create or replace table table2 (province varchar); insert into table2 (province) values (' '), (' '); select trim(province) from table2 where trim(province,' ') = '';

https://docs.snowflake.com/en/sql-reference/functions/trim.html

Answer 2

If the value of mobile_number can be a null or blanks, I normally do something like this: WHERE COALESCE(trim(mobile_number), '') <> ''