为多列构建 TYPE

Build TYPE for many columns

我有以下类型:

TYPE t_my_list is record(col1 VARCHAR2(4000),col2 varchar2(4000),col3 varchar2(4000));
Type  listOfString is table of t_my_list;

然后我在做 BULK COLLECT:

EXECUTE IMMEDIATE v_stmt BULK COLLECT INTO v_ret;

如果我有 20 列怎么办?这样做我认为没有意义:

TYPE t_my_list is record(col1 VARCHAR2(4000),col2 varchar2(4000),....col20 varchar2(200);

还能如何构建 TYPE?

更新:

declare
  TYPE                         t_my_list is record(colX VARCHAR2(4000),colY varchar2(4000),ColZ varchar2(4000));
  Type                         listOfString  is table of t_my_list;
  v_stmt      VARCHAR2(32000) := 'SELECT col1, col2, col2 FROM table_TEST';
  v_ret                        listOfString  := listOfString ();

begin
   EXECUTE IMMEDIATE v_stmt BULK COLLECT INTO v_ret;
   --DBMS_OUTPUT.PUT_LINE('v_ret = '||v_ret.count);   
    for i in v_ret.first..v_ret.last loop
       DBMS_OUTPUT.PUT_LINE('colX: '||v_ret (i).colX||', colY: '||v_ret (i).colY||', ColZ: '||v_ret (i).ColZ);
       --will be done second EXECUTE IMMEDIATE taking as parameter ColX, ColY and ColZ
    end loop;
end;

看起来你并不真的需要使用动态 SQL,所以你可以静态声明一个游标,然后使用该游标的 %rowtype 创建一个集合类型:

declare
  cursor c_my_cursor is select col1, col2, col3 from table_test;
  type t_my_table is table of c_my_cursor%rowtype;
  v_ret t_my_table;
begin
  open c_my_cursor;
  fetch c_my_cursor bulk collect into v_ret;
  close c_my_cursor;

  --DBMS_OUTPUT.PUT_LINE('v_ret = '||v_ret.count);   
  for i in v_ret.first..v_ret.last loop
    DBMS_OUTPUT.PUT_LINE('col1: '||v_ret (i).col1||', col2: '||v_ret (i).col2||', Col3: '||v_ret (i).Col3);
  end loop;
end;
/

这不会在游标上循环,它只是打开它,对集合进行一次批量提取,然后再次关闭它。

如果您出于某种原因选择同一列两次,或者如果您只想坚持 X/Y/Z 命名(或任何您想要的方案),您可以在游标查询中为列添加别名:

  cursor c_my_cursor is select col1 as colx, col2 as coly, col3 as colz from table_test;
...
    DBMS_OUTPUT.PUT_LINE('colX: '||v_ret (i).colX||', colY: '||v_ret (i).colY||', ColZ: '||v_ret (i).ColZ);