When I am using case when to trans string to float data, it can not get a correct response.

The SQL is right here:

• input: one_data is a map where with key and value
• output: get the right value into float value.

SQL:

select 
    case 
        when one_data["name1"] is not null 
            then cast(one_data["name1"] as float) 
            else 0.0 
    end as name1_value 

When I run it, I get a negative value like this:

one_data["name1"]="123" 
name1_value = -123

What is the right answer to use SQL