Oracle存储过程OUT CLOB返回错误字符串缓冲区太小

Posted 2023-03-29

【中文标题】Oracle存储过程OUT CLOB返回错误字符串缓冲区太小

【英文标题】：Oracle Stored Procedure OUT CLOB return error character string buffer too small

【发布时间】：2018-12-04 16:43:47

【问题描述】：

我有一个从应用程序调用的 Oracle 存储过程。存储过程将搜索我的应用程序提供的参数并查询出数据，然后将信息消息返回给我的应用程序。

但是，我得到一个错误

ORA-06502：PL/SQL：数字或值错误：字符串缓冲区太小

在第 37 行，即 P_INFO，我这里使用的是 CLOB 数据类型，假设它可以支持非常大量的字符，假设数据返回超过 100k 个字符。

create or replace PROCEDURE SimpleProcedure
(
  P_ID  VARCHAR2,
  P_INFO OUT CLOB
) AS
  V_PROJ_ID   VARCHAR2(50);
  V_PROJ_NAME NVARCHAR2(1000);
  V_APP_ID     VARCHAR2(50);
  V_APP_STATUS VARCHAR2(50);
  CURSOR SUB_ATTACH_CURSOR(APP_ID VARCHAR2) IS
    SELECT S.SUBMISSION_ID,
           SA.FILE_ID,
           SA.STATUS_CODE,
           E.FILENAME_TEXT
      FROM SUBM_ATTCHMNT SA
     INNER JOIN SUB_SUBMISSION S
        ON S.SUBMISSION_ID = SA.SUBMISSION_ID
     INNER JOIN SUB_FILE E
        ON E.FILE_ID = SA.FILE_ID
     WHERE S.APP_ID = APP_ID;
BEGIN
  SELECT P.PROJECT_ID,
         P.NAME_TEXT,
         A.APP_ID,
         A.STATUS_CODE
    INTO V_PROJ_ID, V_PROJ_NAME, V_APP_ID, V_APP_STATUS
    FROM SUB_APP A
   INNER JOIN SUB_PROJ P
      ON P.PROJECT_ID = A.PROJECT_ID
   WHERE A.ID = P_ID;
  P_INFO := 'Information:
               Proj id: ' || V_PROJ_ID || ',
               Proj name: ' || V_PROJ_NAME || ',
               App id: ' || V_APP_ID || ',
               App status: ' || V_APP_STATUS || ',';
  FOR SA IN SUB_ATTACH_CURSOR(V_APP_ID) LOOP
    P_INFO := P_INFO || 'Submission id: ' || SA.SUBMISSION_ID ||
                 ',file id: ' || SA.FILE_ID || ', file name: ' ||
                 SA.FILENAME_TEXT || ', file Status: ' ||
                 SA.STATUS_CODE || ' ';
  END LOOP;
END SimpleProcedure;

【参考方案1】：

像这样尝试（使用DBMS_LOB.APPEND）：

create or replace PROCEDURE SimpleProcedure(P_ID  VARCHAR2, P_INFO OUT CLOB) AS

  V_PROJ_ID   VARCHAR2(50);
  V_PROJ_NAME NVARCHAR2(1000);
  V_APP_ID     VARCHAR2(50);
  V_APP_STATUS VARCHAR2(50);
  v_SA VARCHAR2(30000); 

  CURSOR SUB_ATTACH_CURSOR(APP_ID VARCHAR2) IS
    SELECT S.SUBMISSION_ID,
           SA.FILE_ID,
           SA.STATUS_CODE,
           E.FILENAME_TEXT
    ...
BEGIN
  SELECT P.PROJECT_ID,
         P.NAME_TEXT,
         A.APP_ID,
         A.STATUS_CODE
     ...    
  P_INFO := 'Information:
               Proj id: ' || V_PROJ_ID || ',
               Proj name: ' || V_PROJ_NAME || ',
               App id: ' || V_APP_ID || ',
               App status: ' || V_APP_STATUS || ',';
  FOR SA IN SUB_ATTACH_CURSOR(V_APP_ID) LOOP
    v_SA := 'Submission id: ' || SA.SUBMISSION_ID ||
                 ',file id: ' || SA.FILE_ID || ', file name: ' ||
                 SA.FILENAME_TEXT || ', file Status: ' ||
                 SA.STATUS_CODE || ' ';
    DBMS_LOB.APPEND(P_INFO, v_SA);
  END LOOP;
END SimpleProcedure;