19

guys. Here's a simple sample two-dimensional array in PL/SQL, which is working perfectly.

declare
  type a is table of number;
  type b is table of a;

  arr b := b(a(1, 2), a(3, 4));
begin
  for i in arr.first .. arr.last loop
    for j in arr(i).first .. arr(i).last loop
      dbms_output.put_line(arr(i) (j));
    end loop;
  end loop;
end;

What I need to do, is to create something similar for a table of RECORDS. Like this:

 type a is record(a1 number, a2 number);
 type b is table of a;

The question is, can I manually initialize this kind of array, or it is supposed to be filled by bulk collects or similar? The same syntax as above doesn't seem to work, and I wasn't able to find any initialization sample in manuals.

3 Answers 3

21

There is no "constructor" syntax for RECORDs, so you have to populate them like this:

declare
 type a is record(a1 number, a2 number);
 type b is table of a;
 arr b := b();
begin
 arr.extend(2);
 arr(1).a1 := 1;
 arr(1).a2 := 2;
 arr(2).a1 := 3;
 arr(2).a2 := 4;
end;
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2 Comments

Yes. I've rarely had any use for RECORD structures, apart the ones that are associated with a table or cursor using %ROWTYPE and are handy for FETCHing into.
hm, well, I use them any time I need a temporary data storage with known data structure - that makes code some sort of self-commenting. maybe that's a bad practice.
16

This works without objects, but you have to declare a constructor function for type 'a' values.

declare  
  type a is record(a1 number, a2 number);
  type b is table of a;

  arr b;

  --Constructor for type a
  function a_(a1 number, a2 number) return a is
    r_a a;
  begin
    r_a.a1 := a1;
    r_a.a2 := a2;

    return(r_a);
  end;

begin
  arr := b(a_(1, 2), a_(3, 4), a_(5, 6), a_(7, 8));

  for i in arr.first .. arr.last loop
    dbms_output.put_line(arr(i).a1||', '||arr(i).a2);
  end loop;
end;

2 Comments

Lovely! Note to anyone re-using this, the function definition has to be the last thing in the declare block (and the compile error you get otherwise is completely unhelpful).
Also, if you run into PLS-00222: no function with name 'b' exists in this scope, you probably added `index by pls_integer' to the table definition. Like I did :) Thanks @Shallow.
4

Since release 18c Qualified Expressions provides an alternative way to define the values of complex data types. Quote:

Starting with Oracle Database Release 18c, any PL/SQL value can be provided by an expression (for example for a record or for an associative array) like a constructor provides an abstract datatype value. In PL/SQL, we use the terms "qualified expression" and "aggregate" rather than the SQL term "type constructor", but the functionality is the same.

Here's an working example:

declare 
    type a is record (a1 number, a2 number);
    type b is table of a index by varchar2 (16);
    arr b := b ('key1' => a (1, 2), 'key2' => a (3, 4)); 
begin 
    declare key varchar2 (16) := arr.first; begin 
    <<foreach>> loop
        dbms_output.put_line (arr(key).a1||','||arr (key).a2);
        key := arr.next (key);
        exit foreach when key is null;
    end loop; end;
end;
/
PL/SQL procedure successfully completed.

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