我想用返回json结构的函数创建一个包，这是包中的代码：
Package 规格

create or replace PACKAGE my_utils IS

    FUNCTION get_json (id_row IN NUMBER, table_name IN VARCHAR2) RETURN CLOB;

END my_utils;

包体

create or replace PACKAGE BODY my_utils IS

    FUNCTION get_json (id_row IN NUMBER, table_name IN VARCHAR2) RETURN CLOB
IS 
    --json_clob CLOB;

    v_stmt VARCHAR2(1000);
    l_sep varchar2(1) := chr(10);
    l_tab varchar2(1) := chr(9);
    up_column VARCHAR2(50);
    low_column VARCHAR2(50);

    cur_asc SYS_REFCURSOR;
    Vcdogcur SYS_REFCURSOR;

    id_ccd number;
    first boolean := true;
begin
    id_ccd := id_row;
    v_stmt := 'select ';

    open cur_asc for 
        SELECT column_name as up_column
              ,lower(column_name) as low_column
        FROM USER_TAB_COLUMNS
        WHERE table_name = upper(table_name);
    loop 
        FETCH cur_asc
        INTO  up_column, low_column;
        EXIT WHEN cur_asc%NOTFOUND;
        if not first then
            v_stmt := v_stmt || ',';
        end if;
        first := false;
        v_stmt := v_stmt || l_sep || l_tab ||up_column || ' as "' || low_column || '"';
    END LOOP;
    v_stmt := v_stmt || l_sep || 'from ' || table_name || l_sep ||'where id = ' || id_ccd;
    DBMS_OUTPUT.PUT_LINE(v_stmt);
    CLOSE cur_asc;

    open Vcdogcur for v_stmt;
        APEX_JSON.initialize_clob_output;
        APEX_JSON.open_object;
        APEX_JSON.write(table_name, Vcdogcur);
        APEX_JSON.close_object;
        DBMS_OUTPUT.put_line(APEX_JSON.get_clob_output);

        --json_clob := APEX_JSON.get_clob_output;

        --APEX_JSON.free_output;
    --CLOSE Vcdogcur;

    --return json_clob;
    return APEX_JSON.get_clob_output;
end;

END my_utils;

我测试了这段代码，并在最后打印了json结构（注解为（**））
现在我想从另一个plsql使用这个函数，我想看到结果，使用以下代码：
案例-1

DECLARE
    SALIDA CLOB;
BEGIN

    SALIDA := mibdes.homeserver_utils.get_json(174, 'my_table_name');
    DBMS_OUTPUT.put_line(SALIDA);

END;
/

但我看不到我想要的结果。我看到这个错误：
错误-->情况1：

Informe de error -
ORA-06502: PL/SQL: error : buffer de cadenas de caracteres demasiado pequeño numérico o de valor
ORA-06512: en "my_schema.my_utils", línea 48
ORA-06512: en línea 10
06502. 00000 -  "PL/SQL: numeric or value error%s"

* Cause:    An arithmetic, numeric, string, conversion, or constraint error

           occurred. For example, this error occurs if an attempt is made to
           assign the value NULL to a variable declared NOT NULL, or if an
           attempt is made to assign an integer larger than 99 to a variable
           declared NUMBER(2).

* Action:   Change the data, how it is manipulated, or how it is declared so

           that values do not violate constraints.

案例-2
第1步：

create table temp_json (
  json_data blob not null
);
alter table temp_json
  add constraint temp_data_json 
  check ( json_data is json );

第2步：

DECLARE
    SALIDA CLOB;
BEGIN

    insert into temp_json (JSON_DATA) values (mibdes.homeserver_utils.get_json(174, 'my_table_name'));

END;
/

错误-->情况2：

Informe de error -
ORA-06502: PL/SQL: error : buffer de cadenas de caracteres demasiado pequeño numérico o de valor
ORA-06512: en "my_schema.my_utils", línea 48
ORA-06512: en línea 14
06502. 00000 -  "PL/SQL: numeric or value error%s"

* Cause:    An arithmetic, numeric, string, conversion, or constraint error

           occurred. For example, this error occurs if an attempt is made to
           assign the value NULL to a variable declared NOT NULL, or if an
           attempt is made to assign an integer larger than 99 to a variable
           declared NUMBER(2).

* Action:   Change the data, how it is manipulated, or how it is declared so

           that values do not violate constraints.

独立运行

CREATE OR REPLACE FUNCTION otro_get_json (id_row     IN NUMBER, 
                                     table_name IN VARCHAR2) RETURN CLOB 
IS 
  --json_clob CLOB; 
  v_stmt     VARCHAR2(1000); 
  l_sep      VARCHAR2(1) := Chr(10); 
  l_tab      VARCHAR2(1) := Chr(9); 
  up_column  VARCHAR2(50); 
  low_column VARCHAR2(50); 
  cur_asc    SYS_REFCURSOR; 
  vcdogcur   SYS_REFCURSOR; 
  --id_ccd     NUMBER; 
  first      BOOLEAN := TRUE; 
BEGIN 
    --id_ccd := id_row; 

    v_stmt := 'select '; 

    OPEN cur_asc FOR 
      SELECT column_name        AS up_column, 
             Lower(column_name) AS low_column 
      FROM   user_tab_columns 
      WHERE  table_name = Upper(table_name); 

    LOOP 
        FETCH cur_asc INTO up_column, low_column; 
        EXIT WHEN cur_asc%NOTFOUND; 
        IF NOT first THEN 
          v_stmt := v_stmt 
                    || ','; 
        END IF; 

        first := FALSE; 
        v_stmt := v_stmt 
                  || l_sep 
                  || l_tab 
                  ||up_column 
                  || ' as "' 
                  || low_column 
                  || '"'; 
    END LOOP; 

    v_stmt := v_stmt 
              || l_sep 
              || 'from ' 
              || table_name 
              || l_sep 
              ||'where id = ' 
              || id_row; 

    --dbms_output.Put_line(v_stmt); 
    CLOSE cur_asc; 
    OPEN vcdogcur FOR v_stmt; 
    apex_json.initialize_clob_output; 
    apex_json.open_object; 
    apex_json.WRITE(table_name, vcdogcur); 
    apex_json.close_object; 
    --dbms_output.Put_line(apex_json.get_clob_output); 

    --json_clob := APEX_JSON.get_clob_output; 
    --APEX_JSON.free_output; 
    --CLOSE Vcdogcur; 
    --return json_clob; 
    RETURN apex_json.get_clob_output; 
END; 
/

函数编译正确，没有错误，但当我想使用它时：

DECLARE
    SALIDA CLOB;
BEGIN
    SALIDA := otro_get_json(174, 'my_table_name');
    DBMS_OUTPUT.put_line(SALIDA);

END;
/

错误-->独立函数：

Informe de error -
ORA-06502: PL/SQL: error : buffer de cadenas de caracteres demasiado pequeño numérico o de valor
ORA-06512: en "my_schema.OTRO_GET_JSON", línea 34
ORA-06512: en línea 10
06502. 00000 -  "PL/SQL: numeric or value error%s"

* Cause:    An arithmetic, numeric, string, conversion, or constraint error

           occurred. For example, this error occurs if an attempt is made to
           assign the value NULL to a variable declared NOT NULL, or if an
           attempt is made to assign an integer larger than 99 to a variable
           declared NUMBER(2).

* Action:   Change the data, how it is manipulated, or how it is declared so

           that values do not violate constraints.

有什么问题，我该如何解决？
我的函数返回如下内容：

{
  "my_table_name": [
    {
      "created": "2020-06-04T08:10:09.000000000Z",
      "created_by": "APEX_APP",
      "updated": "2020-06-04T10:10:09.295632000Z",
      "updated_by": "APEX_APP",
      "id": 174,
      "text": "ALL",
      "part": 2770,
      "code": 2212,
      "date": "2017-01-01T00:00:00.000000000Z",
      "percentage": -4.98
    }
  ]
}

但我需要看到或打印salida变量。
非常感谢