sql - 从 plsql 输出/返回的 CLOB 值(指定的 LOB 定位器无效 : ORA-22275)

Question

我有存储的 plsql 过程，它从文件中获取大文本

create or replace 
procedure dbst_load_a_file( p_file_name in varchar2, l_clob  out  clob )
    as
        l_bfile   bfile;
        dst_offset  number := 1 ;
        src_offset  number := 1 ;
        lang_ctx    number := DBMS_LOB.DEFAULT_LANG_CTX;
        warning     number;
    begin
        l_bfile := bfilename( 'SCHEMES_OF_PS', p_file_name );
        dbms_lob.fileopen( l_bfile );
        dbms_lob.loadclobfromfile(
          DEST_LOB     => l_clob
        , SRC_BFILE    => l_bfile
        , AMOUNT       => dbms_lob.getlength( l_bfile )
        , DEST_OFFSET  => dst_offset
        , SRC_OFFSET   => src_offset
        , BFILE_CSID   => DBMS_LOB.DEFAULT_CSID
        , LANG_CONTEXT => lang_ctx
        , WARNING      => warning);
        dbms_lob.fileclose( l_bfile );
    end;

然后我尝试以这种方式使用它:

  insert into SCHEME_SOURCE (SOURCE, ID, CODE) 
  values (exec dbst_load_a_file( 'SCHEMES_OF_PS', 'Konotop.svg' ), 15, 'Konotop');

或更正确:

declare
  myVal clob := empty_clob();

begin
  DBMS_OUTPUT.PUT_LINE(myVal);
  dbst_load_a_file('Konotop.svg', myVal);
  DBMS_OUTPUT.PUT_LINE(myVal);
end;

在第二种情况下我得到一个错误

PL/SQL: numeric or value error: invalid LOB locator specified: ORA-22275

在第一种情况下，我怀疑语法不存在。

我如何从存储的 plsql 中使用它的过程/函数输出/返回 CLOB 参数

如果我有这个代码

create or replace
function dbst_load_a_file2( p_file_name in varchar2 ) return clob
    is
        l_clob  clob;
        l_bfile   bfile;
        dst_offset  number := 1 ;
        src_offset  number := 1 ;
        lang_ctx    number := DBMS_LOB.DEFAULT_LANG_CTX;
        warning     number;
    begin
        l_bfile := bfilename( 'SCHEMES_OF_PS', p_file_name );
        dbms_lob.fileopen( l_bfile );
        dbms_lob.loadclobfromfile( 
          DEST_LOB     => l_clob
        , SRC_BFILE    => l_bfile
        , AMOUNT       => dbms_lob.getlength( l_bfile )
        , DEST_OFFSET  => dst_offset
        , SRC_OFFSET   => src_offset
        , BFILE_CSID   => DBMS_LOB.DEFAULT_CSID
        , LANG_CONTEXT => lang_ctx
        , WARNING      => warning);
        dbms_lob.fileclose( l_bfile );
        return l_clob;
    end;

  insert into SCHEME_SOURCE (SOURCE, ID, CODE) 
  values (dbst_load_a_file2('Konotop.svg' ), 15, 'Konotop');

然后又报错

SQL Error: ORA-06502: PL/SQL: numeric or value error: invalid LOB locator specified: ORA-22275 ORA-06512: at "SYS.DBMS_LOB", line 890 ORA-06512: at "VAG.DBST_LOAD_A_FILE2", line 12

谢谢

Answer 1

此时:

    dbms_lob.loadclobfromfile(
      DEST_LOB     => l_clob

...您的l_clob OUT 参数尚未初始化。使它成为一个空的 CLOB 也不起作用(因此，即使您将 l_clob 设置为 IN OUT 参数，它仍然会报错)as the documentation for empty_clob mentions :

You cannot use the locator returned from this function as a parameter to the DBMS_LOB package or the OCI.

您可以改用临时 CLOB，方法是在尝试使用它之前添加对 dbms_lob.createtemporary(l_clob, true) 的调用:

...
begin
    l_bfile := bfilename( 'SCHEMES_OF_PS', p_file_name );
    dbms_lob.fileopen( l_bfile );
    dbms_lob.createtemporary(l_clob, true);
    dbms_lob.loadclobfromfile(
      DEST_LOB     => l_clob
      ...

然后你在调用它的时候不需要给它一个初始的空值:

declare
  myVal clob;
begin
  dbst_load_a_file('Konotop.svg', myVal);
  DBMS_OUTPUT.PUT_LINE(myVal);
end;
/

这也是一个函数:

create or replace 
function dbst_load_a_file( p_file_name in varchar2) return clob
as
    l_clob    clob;
    l_bfile   bfile;
    dst_offset  number := 1 ;
    src_offset  number := 1 ;
    lang_ctx    number := DBMS_LOB.DEFAULT_LANG_CTX;
    warning     number;
begin
    l_bfile := bfilename( 'SCHEMES_OF_PS', p_file_name );
    dbms_lob.fileopen( l_bfile );
    dbms_lob.createtemporary(l_clob, true);
    dbms_lob.loadclobfromfile(
      DEST_LOB     => l_clob
    , SRC_BFILE    => l_bfile
    , AMOUNT       => dbms_lob.getlength( l_bfile )
    , DEST_OFFSET  => dst_offset
    , SRC_OFFSET   => src_offset
    , BFILE_CSID   => DBMS_LOB.DEFAULT_CSID
    , LANG_CONTEXT => lang_ctx
    , WARNING      => warning);
    dbms_lob.fileclose( l_bfile );
    return l_clob;
end;
/

select dbst_load_a_file('Konotop.svg') from dual;

或者在您编辑的问题中使用 insert。