Question

I’m new in PLSQL (about a week) and I have an object with hundreds attributes and I need to check which ones are filled and null to add to a clob.

It is possible to iterate in the object attributes like

for i in object loop
   object.i
end loop;

Answer 1

Using standard PL/SQL construct you cannot. You can iterate through a collection using

for i in mycol.FIRST .. mycol.LAST loop

Variable i is not index but one element of the iterated collection.

If your object is an Oracle TYPE you can query a system view ALL_TYPE_ATTRS. This view is part of a database catalog. You find its description in Oracle Reference (not Oracle SQL Reference!). You get a list of attribute names, I’m not sure, if you can access it in dynamic way.

The simplest way is to write a set of helper procedures which will check an attribute according its type and manage its value and then simply call this procedure.

declare
    procedure Manage_Char_Attr(value IN VARCHAR2, pclob CLOB) IS
    BEGIN
      if value is null then
        ...
    END;
    procedure Manage_Number_Attr(value IN NUMBER, pclob CLOB) IS
    ...
    procedure Manage_Date_Attr(value IN DATE, pclob CLOB) IS
    ...

    CLOB myclob

begin
    -- initialize your CLOB
    ... 
    -- manage attributes
    Manage_Char_Attr(attr1, myclob); -- let attr1 is a string
    Manage_Char_Attr(attr2, myclob); -- let attr2 is a string
    Manage_Numvber_Attr(attr3, myclob); -- let attr3 is a number
    Manage_Date_Attr(attr4, myclob); -- let attr4 is a date
    ...
end;