oracle - Error: PLS-00428: an into clause is expected in this select statement

Question

I'm trying to create a function as shown below but getting the error stated in the title.

create or replace function gettaxmin(period_tax_type_id in double precision, tax_range in number) return double precision is
  Result double precision;
begin
  SELECT CASE WHEN max(tax_range) is null THEN 0 ELSE max(tax_range) END 

    FROM period_tax_rates WHERE (tax_range < 1) AND (period_tax_type_id = 2);
  return(Result);
end gettaxmin;

Any ideas?

Answer 1

You have to store the result of your SELECT statement into a variable (in this case, "Result"):

create or replace function gettaxmin
            (period_tax_type_id in double precision, tax_range in number) 
    return double precision 
is
     Result double precision;
begin
  SELECT CASE WHEN max(tax_range) is null THEN 0 ELSE max(tax_range) END 
    INTO Result 
    FROM period_tax_rates WHERE (tax_range < 1) AND (period_tax_type_id = 2);
  return Result;
end gettaxmin;