如何在Oracle PL/SQL类型中定义无参数构造函数？

Question

如何在Oracle PL/SQL类型中定义无参数构造函数？我试过这个:

create or replace type FooBar as object
(
    constructor function FooBar() return self as result
);

...

foo_bar := FooBar();

但是类型声明中的空参数列表会引发PLS-00103.

Answer 1

在无参数函数的名称后面不需要括号,你需要一个构造函数体的定义:

create or replace type FooBar as object
(
    bar NUMBER(1,0)
    ,constructor function FooBar return self as result
);
/


create or replace type body FooBar is

    constructor function FooBar return self as result
    IS
    BEGIN
    RETURN;
    END;
end;
/


    declare 
     foo foobar;
    begin
      foo := foobar();
    end;
   /