CODEWITHSUNDEEP
sqlsqlite
Bentaiba Miled Basma
Bentaiba Miled Basma

Reputation: 587

Force sqlite select query to return nothing instead of null

I have a query similar to this:

select distinct 'density' as feature, density as value, 
       count(density) as frequency 
from cases
where density in not null;

Let's call it query A, and the next query is query B.

In the case when the query B:

select distinct density as value, count(density) as frequency 
from cases
where density in not null;

returns nothing, query A returns a line contains:

('density', null, null)

but I want from query A to return nothing. The question is, how to refactor the query A to force it to return nothing in the explained case?

Upvotes: 0

Views: 171

Answers (1)

Gordon Linoff
Gordon Linoff

Reputation: 1269563

Try doing this:

select 'density' as feature, density as value, 
       count(density) as frequency 
from cases
where density is not null
group by density;

If all the rows are filtered out by the where, then the group by will return no rows at all.

Upvotes: 1

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