Oracle导出clob字段到csv

news2024/10/6 10:40:46

使用UTL_FILE

ref: How to Export The Table with a CLOB Column Into a CSV File using UTL_FILE ?(Doc ID 1967617.1)

--preapre data
CREATE TABLE TESTCLOB(ID NUMBER, MYCLOB1 CLOB, MYCLOB2 CLOB );
INSERT INTO TESTCLOB(ID,MYCLOB1,MYCLOB2) VALUES(1,'Sample row 11', 'Sample row 12');
INSERT INTO TESTCLOB(ID,MYCLOB1,MYCLOB2) VALUES(2,'Sample row 21', 'Sample row 22');
INSERT INTO TESTCLOB(ID,MYCLOB1,MYCLOB2) VALUES(3,'Sample row 31', 'Sample row 32');
INSERT INTO TESTCLOB(ID,MYCLOB1,MYCLOB2) VALUES(4,'Sample row 41', 'Sample row 42');
INSERT INTO TESTCLOB(ID,MYCLOB1,MYCLOB2) VALUES(5,'Sample row 51', 'Sample row 52');
COMMIT;

column MYCLOB1 format a20
column MYCLOB2 format a20
SELECT * FROM TESTCLOB;

--create directory
CREATE OR REPLACE DIRECTORY MYDIR AS '/u02/';


--create function
CREATE OR REPLACE FUNCTION EXPORT_TABLE_TO_CSV_FILE(p_query     in dbms_sql.varchar2a,
                                                      p_separator in varchar2 default ',',
                                                      p_dir       in varchar2,
                                                      p_filename  in varchar2,
                                                      p_is_head   in boolean default false)
  RETURN NUMBER is
  l_output        utl_file.file_type;
  l_theCursor     integer default dbms_sql.open_cursor;
  l_columnValue   varchar2(2000);
  l_columnValClob clob;
  l_status        integer;
  l_colCnt        number default 0;
  l_separator     varchar2(10) default '';
  l_cnt           number default 0;
  l_col_desc      dbms_sql.desc_tab;
  l_offset        integer;
BEGIN
  dbms_sql.parse(l_theCursor,
                 p_query,
                 p_query.first,
                 p_query.last,
                 true,
                 dbms_sql.native);
  dbms_sql.describe_columns(l_theCursor, l_colCnt, l_col_desc);
  for i in 1 .. l_colCnt loop
    if l_col_desc(i).col_type = 112 then
      dbms_sql.define_column(l_theCursor, i, l_columnValClob);
    else
      dbms_sql.define_column(l_theCursor, i, l_columnValue, 4000);
    end if;
  end loop;
  l_status := dbms_sql.execute(l_theCursor);
  if dbms_sql.fetch_rows(l_theCursor) > 0 then
    l_output := utl_file.fopen(p_dir, p_filename, 'w', 32767);
    if p_is_head then
      for i in 1 .. l_col_desc.count loop
        utl_file.put(l_output, l_separator || l_col_desc(i).col_name);
        l_separator := p_separator;
      end loop;
      utl_file.new_line(l_output);
    end if;
    loop
      l_separator := '';
      for i in 1 .. l_colCnt loop
        if l_col_desc(i).col_type = 112 then
          l_offset := 1;
          dbms_sql.column_value(l_theCursor, i, l_columnValClob);
          utl_file.put(l_output, l_separator);
          loop
            l_columnValue := dbms_lob.substr(l_columnValClob,
                                             2000,
                                             l_offset);
            -- dbms_output.put_line(l_columnValue);
            l_offset := l_offset + 2000;
            utl_file.put(l_output, l_columnValue);
            exit when trim(l_columnValue) is null;
          end loop;
        else
          dbms_sql.column_value(l_theCursor, i, l_columnValue);
          utl_file.put(l_output, l_separator || l_columnValue);
        end if;
        l_separator := p_separator;
      end loop;
      utl_file.new_line(l_output);
      l_cnt := l_cnt + 1;
      exit when(dbms_sql.fetch_rows(l_theCursor) <= 0);
    end loop;
  end if;
  dbms_sql.close_cursor(l_theCursor);
  utl_file.fclose(l_output);
  return l_cnt;
END;
/



set serverout on
DECLARE
  l_sql dbms_sql.varchar2a;
  l_cnt integer;
BEGIN
  l_sql(1) := 'SELECT * FROM TESTCLOB';
  l_cnt := export_table_to_csv_file(l_sql,
                                    ',',
                                    'MYDIR',
                                    'csvsample.csv',
                                    TRUE);
END;
/