oracle18c function return table - oracle

Question

I'm trying to recover a bunch of data in the form of a table
I created the type as follows
create or replace type Structure_type AS OBJECT
(
SWID Integer,
structure_TYPESid Integer,
MAIN_BRANCHid Integer,
Organizational_structureid Integer,
Administrative_structureid Integer,
structure_tree NVarchar2(1000),
structure_NO NVarchar2(500),
Structure_level Integer
)
and create table of type
create or replace type Structure_table_type as table of Structure_type;
Then I created a data retrieval function like the following
create or replace function Get_Who_Runs_Stores
(OoA char) return Structure_table_type is
FunctionResult Structure_table_type;
begin
FunctionResult :=Structure_table_type();
CASE UPPER(OoA)
WHEN 'A' then
FOR x_Structure IN (select b.administrative_tree
from warehouse w join branches_costcenter b on (w.w_branch=b.swid))
LOOP
select
b.swid SWID,
b.costcenter_type_id structure_TYPESid ,
b.main_branch_id MAIN_BRANCHid,
b.direct_branch_cost_center_id Organizational_structureid,
b.direct_adminstration_parent_id Administrative_structureid,
b.administrative_tree structure_tree,
b.administrative_no structure_NO,
b.administrative_level Structure_level
into FunctionResult
from branches_costcenter b
where
x_Structure.Administrative_Tree like '%-' || b.swid || '-%';
end loop;
WHEN 'O' then
FOR x_Structure IN (select b.organizationa_tree
from warehouse w join branches_costcenter b on (w.w_branch=b.swid))
LOOP
select b.swid SWID,b.costcenter_type_id structure_TYPESid ,
b.main_branch_id MAIN_BRANCHid, b.direct_branch_cost_center_id Organizational_structureid,
b.direct_adminstration_parent_id Administrative_structureid,b.organizationa_tree structure_tree,
b.organizationa_no structure_NO ,b.organizationa_level Structure_level into FunctionResult
from branches_costcenter b
where
x_Structure.Organizationa_Tree like '%-' || b.swid || '-%';
end loop;
else
return null;
end case ;
return(FunctionResult);
end Get_Who_Runs_Stores;
Error: PL/SQL: ORA-00947: not enough values
Line: 45
Text: from branches_costcenter b
I tried the SQL sentence and it works correctly
select
b.swid SWID,
b.costcenter_type_id structure_TYPESid ,
b.main_branch_id MAIN_BRANCHid,
b.direct_branch_cost_center_id Organizational_structureid,
b.direct_adminstration_parent_id Administrative_structureid,
b.administrative_tree structure_tree,
b.administrative_no structure_NO,
b.administrative_level Structure_level
from branches_costcenter b
where
'-1-2-3-12-24-' like '%-' || b.swid || '-%';
How can I get the required data and what is the best way to do so?
Do I have to define all that I want to retrieve data from the function in the form of a table?
Sorry, my English is bad

Answer 1

Your function will be horrible slow. Apart from that the issue is following: If you run
FOR x_Structure IN (select ...) LOOP
SELECT ...
INTO FunctionResult
FROM ...;
END LOOP;
RETURN FunctionResult;
then you insert row by row into FunctionResult. At the end you return only the last row from your select, all other rows have been overwritten.
Try
SELECT ...
BULK COLLECT INTO FunctionResult
FROM ...;
You could also insert row by row, but this is much slower:
FOR x_Structure IN (select ...) LOOP
FunctionResult.Extend();
SELECT ...
INTO FunctionResult(FunctionResult.LAST)
FROM ...;
END LOOP;
You cannot select into FunctionResult directly. The statement must be like this:
SELECT Structure_type(b.swid, b.costcenter_type_id, ..., b.administrative_level)
BULK COLLECT INTO FunctionResult
FROM ...
Update
Depending on your client it might be easier and better to return a RefCursor. Would be like this:
create or replace function Get_Who_Runs_Stores(OoA char) return SYS_REFCURSOR is
res SYS_REFCURSOR;
begin
OPEN res FOR
SELECT b.swid SWID,b.costcenter_type_id structure_TYPESid, ...
FROM ...
WHERE ...;
RETURN res;
end;
You don't have to create any TABLE or OBJECT type, just return the RefCursor.