4

For some reason, I have certain fields in a table, that are collections of chars. Chars of different length. Example:

create or replace type t_charray_1 as varray(5) of char(1);
create or replace type t_charray_2 as varray(5) of char(2);
create or replace type t_charray_3 as varray(5) of char(3);
create or replace type t_charray_4 as varray(5) of char(4);

create table mytable (
field1 number,
field2 t_charray_1,
field3 t_charray_3,

Also, I have a function that returns a (fixed length) string representation of a mytable record. This function calls other functions that are returning the string representation of a given collection-typed field. Examples:

  function to_chr(
    p_array in t_charray_1, 
    pad_length in number, 
    p_list_length in number
  ) return char as
    v_res varchar2(255) := '';
  begin
    for i in 1 .. p_list_length loop
      if p_array is not null and p_array.exists(i) and p_array(i) is not null then
        v_res := v_res || rpad(p_array(i), pad_length, ' ');
      else
        v_res := v_res || rpad(' ', pad_length, ' ');
      end if;
    end loop;
    return v_res;
  end to_chr;
  ------------------------------------------------------------------------------
  function to_chr(
    p_array in t_charray_2, 
    pad_length in number, 
    p_list_length in number
  ) return char as
    v_res varchar2(255) := '';
  begin
    for i in 1 .. p_list_length loop
      if p_array is not null and p_array.exists(i) and p_array(i) is not null then
        v_res := v_res || rpad(p_array(i), pad_length, ' ');
      else
        v_res := v_res || rpad(' ', pad_length, ' ');
      end if;
    end loop;
    return v_res;
  end to_chr;

Note that these functions are overloaded versions of each other. The only difference in their signature is the type of the p_array argument.

Please also note that the bodies of these functions are identical.

Motivation

I want to eliminate duplicate code. What are my choices?

EDIT I have heard of sys.anydata but never used it. Can it be a solution?

4

2 回答 2

2

尝试：

create or replace function to_chr(p_array       in anydata,
                                  pad_length    in number,
                                  p_list_length in number) return char as

  v_res varchar2(255) := '';
  x     number;

  v_array t_charray_4;

  v_array1 t_charray_1;
  v_array2 t_charray_2;
  v_array3 t_charray_3;

begin

  dbms_output.put_line(p_array.GetTypeName);
  case p_array.GetTypeName
    when '<schema>.T_CHARRAY_1' then
      x := p_array.GetCollection(v_array1);
      select cast(v_array1 as t_charray_4) into v_array from dual;
    when '<schema>.T_CHARRAY_2' then
      x := p_array.GetCollection(v_array2);
      select cast(v_array2 as t_charray_4) into v_array from dual;
    when '<schema>.T_CHARRAY_3' then
      x := p_array.GetCollection(v_array3);
      select cast(v_array3 as t_charray_4) into v_array from dual;
    when '<schema>.T_CHARRAY_4' then
      x := p_array.GetCollection(v_array);
  end case;

  for i in 1 .. p_list_length loop
    if v_array is not null and v_array.exists(i) and v_array(i) is not null then
      v_res := v_res || rpad(v_array(i), pad_length, ' ');
    else
      v_res := v_res || rpad(' ', pad_length, ' ');
    end if;
  end loop;
  return v_res;
end to_chr;

你可以像这样运行它：

declare
  p_array anydata;
  v_array t_charray_3 := new t_charray_3('aaa', 'bbb');
  v_res   varchar2(255);
begin
  p_array := anydata.convertcollection(v_array);

  v_res := to_chr(p_array => p_array, pad_length => 2, p_list_length => 3);
end;
于 2012-10-31T13:08:42.943 回答
2

您可以编写一个采用最大类型的过程，并在传递较小的类型之前显式地将它们转换为较大的类型。注意 CAST 只能在 SQL 中使用

DECLARE

  x t_charray_1 := t_charray_1();
  y t_charray_2 := t_charray_2();

  PROCEDURE foo( p_foo t_charray_2 )
  AS
  BEGIN
    FOR i IN p_foo.FIRST..p_foo.LAST loop
      dbms_output.put_line( p_foo(i) );
    END LOOP;
  END;

BEGIN
  x.EXTEND;
  x.EXTEND;
  x(1) := 'A';
  x(2) := 'B';

  y.EXTEND;
  y.EXTEND;
  y(1) := 'AA';
  y(2) := 'BB';

  foo(y);

  SELECT CAST(x AS t_charray_2) INTO y FROM dual;
  foo(y);
END;
/
于 2012-10-31T12:44:12.473 回答