Dynamic PL/SQL query, how to ignore null parameters? - sql

Question

I have a PL/SQL procedure with multiple parameters. When a webapp calls the procedure, if it's not using a certain parameter, it passes is as null, ie
procedure test (param1 in varchar2, param2 in varchar2, param3 in varchar2, cursor out sys_refcursor)
...
end procedure test;
I want to make an SQL query where I include the given parameters in the WHERE clause only if the parameter is not null. Is there a way to achieve this in an elegant way, other than building the SQL query in a string and then opening the cursor for that string, like this
vSQL := 'SELECT * from TABLE WHERE something = something_else';
if param1 IS NOT NULL
vSQL := vSQL || 'AND some_param = ' || param1;

Answer 1

I have answered a similar question on dba.stackexchange.com

Answer 2

You can code it all into a single select
SELECT * from TABLE WHERE something = something_else
AND ((param1 IS NOT NULL AND some_param = param1) OR 1)

Answer 3

Create a test table:
create table testtab
(
name_first varchar2(50),
name_last varchar2(50),
name_middle varchar2(50)
);
insert into testtab values ('Joe', 'Jones', 'A');
insert into testtab values ('Joe', 'Smith', 'A');
insert into testtab values ('Steve', 'Jones', 'B');
insert into testtab values ('Axl', 'Rose', 'C');
insert into testtab values ('Phil', 'McCracken', 'D');
commit;
Create your procedure:
CREATE OR REPLACE procedure ECDATA.get_testtab_rows
(i_name_first in varchar2 default null,
i_name_last in varchar2 default null,
i_name_middle in varchar2 default null,
o_cursor out sys_refcursor
) as
v_result_cur sys_refcursor;
begin
open v_result_cur for
select * from testtab
where name_first like nvl(i_name_first, '%')
and name_last like nvl(i_name_last, '%')
and name_middle like nvl(i_name_middle, '%')
;
o_cursor := v_result_cur;
end;
/
Then call it like this:
declare
v_cur sys_refcursor;
testtab_rec testtab%rowtype;
begin
get_testtab_rows(i_name_last=>'Jones', o_cursor=>v_cur);
loop
fetch v_cur into testtab_rec;
exit when v_cur%notfound;
dbms_output.put_line(testtab_rec.name_first || ' ' || testtab_rec.name_middle || ' ' || testtab_rec.name_last);
end loop;
exception
when others then raise;
end;