Oracle CLOB转换BLOB方法

CREATE OR REPLACE FUNCTION clob_to_blob(b IN CLOB DEFAULT empty_clob()) RETURN BLOB IS
  res          BLOB;
  b_len        NUMBER := dbms_lob.getlength(b);
  dest_offset1 NUMBER := 1;
  src_offset1  NUMBER := 1;
  amount_c     INTEGER := dbms_lob.lobmaxsize;
  blob_csid    NUMBER := dbms_lob.default_csid;
  lang_ctx     INTEGER := dbms_lob.default_lang_ctx;
  warning      INTEGER;
BEGIN
  IF b_len > 0 THEN
    dbms_lob.createtemporary(res,TRUE);
    dbms_lob.open(res ,dbms_lob.lob_readwrite);
    dbms_lob.converttoblob(res,b,amount_c,dest_offset1,src_offset1,blob_csid,lang_ctx,warning);
  ELSE
    SELECT empty_blob() INTO res FROM dual;
  END IF;
  RETURN res;
END clob_to_blob;

-- 刘轶鹤