[置顶] 使用oracle压缩blob对象



1、使用oracle压缩blob对象

l_blob := utl_compress.lz_compress(l_blob);

2、将blob转换成clob

FUNCTION   blob_to_clob(blob_in   IN   BLOB )   RETURN   CLOB   AS

    v_clob      CLOB ;

    v_varchar   VARCHAR2 ( 32767   );

    v_start     PLS_INTEGER   :=   1   ;

    v_buffer    PLS_INTEGER   :=   32767   ;

    tmp_num     NUMBER ;

    BEGIN

    dbms_lob.createtemporary(v_clob,   TRUE );

    tmp_num := ceil(dbms_lob.getlength(blob_in) / v_buffer);

      IF   tmp_num >   0   THEN

        --防止传入的BLOB为NULL或长度为0时引发错误

        FOR   i   IN   1   .. tmp_num   LOOP

        v_varchar := utl_raw.cast_to_varchar2(dbms_lob.substr(blob_in,

                                                              v_buffer,

                                                              v_start));

        dbms_lob.writeappend(v_clob, length(v_varchar), v_varchar);

        v_start := v_start + v_buffer;

        END   LOOP   ;

      END   IF   ;

      RETURN   v_clob;

    END   blob_to_clob;

3、将clob数据插入文件中

dbms_xslprocessor.clob2file(l_clob, p_dir_name, p_file_name);