when i using case when to trans string to float data, it can not get right error,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 is it,get neg value such:
one_data[“name1″]=”123”
name1_value = -123

what is the right answer to use sql