PL/SQL 3.3以上的版本中，UTL_FILE包答应用户通过PL/SQL读写操作系统文件。如下：
declare
file_handle UTL_FILE.FILE_TYPE;
begin
file_handle := UTL_FILE.FOPEN('TMP', '文件名', 'w',[1-32767]);
--四个参数：目录，文件名，打开方式，最大行数(默认为2000)
UTL_FILE.PUTF(file_handle, '写入的信息\n');
UTL_FILE.FCLOSE(file_handle);
exception
WHEN utl_file.invalid_path THEN
raise_application_error(-20000, 'ERROR: Invalid path for file or path not in INIT.ORA.');
end;
PutF()过程用来以指定格式把文本写入一个文件
Put_Line()过程把一个指定的字符串写入文件并在文件中开始新的一行
9i中函数说明：
UTL_FILE.FOPEN (
location IN VARCHAR2,
filename IN VARCHAR2,
open_mode IN VARCHAR2,
max_linesize IN BINARY_INTEGER)
RETURN file_type;
Parameters Description
location (IN) The Directory location of the source file, a DIRECTORY_NAME from the ALL_DIRECTORIES view (case sensitive)
filename File name, including extension (file type), without directory path. In Unix,the filename cannot end with /.
一个使用文件的测试
1、用sys用户登录到数据库(ora9i):conn sys/orcl@eai01 as sysdba
2、在sqlplus中运行create or replace directory TMP as 'd:\testtmp';
在sqlplus中运行grant read on directory TMP to public
3、在scott用户下建立存储过程如：pReadFileTest
CREATE OR REPLACE PROCEDURE pReadFileTest
(FPATH IN STRING,FNAME IN STRING,MAX_NUM IN NUMBER)
IS
FILE_HANDLE UTL_FILE.FILE_TYPE;
TEXT_BUFFER STRING(1000);
LINE_NUM NUMBER;
BEGIN
DBMS_OUTPUT.PUT_LINE('INPUT PATH='FPATH);
DBMS_OUTPUT.PUT_LINE('INPUT FILENAME='FNAME);
LINE_NUM :=0;
BEGIN
FILE_HANDLE := UTL_FILE.FOPEN(FPATH,FNAME,'R',MAX_NUM);
LOOP
LINE_NUM:= LINE_NUM + 1;
UTL_FILE.GET_LINE(FILE_HANDLE,TEXT_BUFFER);
DBMS_OUTPUT.PUT_LINE('LINE'LINE_NUM' : 'TEXT_BUFFER);
END LOOP;
EXCEPTION
WHEN NO_DATA_FOUND THEN
RETURN;
WHEN UTL_FILE.INVALID_PATH THEN
DBMS_OUTPUT.PUT_LINE('INVALID PATH');
WHEN UTL_FILE.INVALID_MODE THEN
DBMS_OUTPUT.PUT_LINE('INVALID MODE');
WHEN UTL_FILE.INVALID_FILEHANDLE THEN
DBMS_OUTPUT.PUT_LINE('INVALID FILEHANDLE');
WHEN UTL_FILE.INVALID_OPERATION THEN
DBMS_OUTPUT.PUT_LINE('INVALID OPERATION');
WHEN UTL_FILE.READ_ERROR THEN
DBMS_OUTPUT.PUT_LINE('READ ERROR');
WHEN UTL_FILE.WRITE_ERROR THEN
DBMS_OUTPUT.PUT_LINE('WRITE ERROR');
WHEN UTL_FILE.INTERNAL_ERROR THEN
DBMS_OUTPUT.PUT_LINE('INTERNAL ERROR');
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE(SQLERRM);
END;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('OTHER ERROR='SQLERRM);
END pReadFileTest;
4、在sqlplus中运行set serveroutput on
5、exec pReadFileTest('TMP','A.TXT','R')
6、正常输出
小结：在9i中可以不在init.ora中增加utl_file_dir目录，而是在sys用户下创建一个directory目录（实际上是在sys用户下的dir$表中增加一个对应的OS_PATH），然后将对该directory对象的读/写操作的权限grant给public。
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