user defined type as input parameters in PostgreSQL function

Question

Hi I am creating a procedure for insertion of meta data. I created types and I included 1 type in another type and in procedure I am iterating it to get the value. Since I am new to PostgreSQL Can anyone help me on how to call the procedure. The input parameter is type

Create Type Form_details as(
                     formName character varying(100),
                     submittedBy numeric,
                      createdDate date,    
                     updatedBy numeric,
                     updatedDate date,
                     comments character varying(500),
                  Sections Section[]  

)

create type Section as (
                           sectionName character varying(100),
                           sectionLabel character varying(100),                           
                           sectionOrder numeric                           



                     )

and the procedure I wrote is

    CREATE OR REPLACE FUNCTION form_insertion(formdetails form_details[])
  RETURNS character varying AS
$BODY$

DECLARE 
         form_details_seq integer;
         section_seq integer;
         formName character varying(100);
         submittedBy numeric;
         createdDate date;    
         comments character varying(500);
                formStatusId numeric;

         sectionOrder numeric;
         sectionName character varying(100);
         sectionLabel character varying(100);
         attributeId numeric;

         I integer;
         J integer;
begin
FOR I IN 1..formdetails.COUNT

LOOP

formName             :=formdetails[I].formName;
formStatusId         :=formdetails[I].formStatusId;
comments             :=formdetails[I].comments;
  RAISE NOTICE '%', formName;

  FOR J IN 1..formdetails.Section.COUNT
   LOOP

   sectionName             :=formdetails[I].Section[J].sectionName;
 RAISE NOTICE '%', sectionName;

   END LOOP ;


END LOOP;

Return formName,sectionName;
end;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

This is not complete procedure. But I am trying to test with this. Can you please let me know whether my approach is correct and how can I test it from DB side. How I will pass this parameter. By the way the type I created is from Java object. this procedure will be calling from Java end. Any help would be greatly appreciated.

Answer 1

To call the function from a SQL query, you must cast the parameters to your custom type as in the following example.

select form_insertion(array[
    cast(row('Form 1', 1, current_date, 1, current_date, 'This is form 1', 
        array[
            cast(row('section-1', 'Section One', 1) as section),
            cast(row('section-2', 'Section Two', 2) as section),
            cast(row('section-3', 'Section Three', 3) as section)
        ]
    ) as form_details),
    cast(row('Form 2', 2, current_date, 1, current_date, 'This is form 2', 
        array[
            cast(row('section-2', 'Section Two', 2) as section),
            cast(row('section-3', 'Section Three', 3) as section)
        ]
    ) as form_details),
    cast(row('Form 3', 1, current_date, 1, current_date, 'This is form 3', 
        array[
            cast(row('section-1', 'Section One', 1) as section),
            cast(row('section-3', 'Section Three', 3) as section)
        ]
    ) as form_details)
])

Note that PostgreSQL arrays don't have a .COUNT property. You can iterate through an array by index range with array_upper function:

for i IN 1..array_upper(formdetails, 1)
LOOP 
   -- your code here
END LOOP;

Since PostgreSQL 9.1, you can use the FOREACH statement to loop through the array:

create or replace function form_insertion(formdetails form_details[])
    returns varchar as $$
declare
    detail form_details;
    sec section;
begin
    foreach detail in array formdetails
    LOOP 
       RAISE NOTICE '%', detail.formName;

       foreach sec in array detail.sections
       LOOP
         raise NOTICE '%', sec.sectionName;
       END LOOP;
    END LOOP;
    return '';
end;$$
    language plpgsql;