Using Create directory & UTL_FILE in Oracle

Create directory让我们可以在Oracle数据库中灵活的对文件进行读写操作，极大的提高了Oracle的易用性和可扩展性。

其语法为:

CREATE [OR REPLACE] DIRECTORY directory AS 'pathname';

for example:

 

create or replace directory exp_dir as '/tmp';

目录创建以后，就可以把读写权限授予特定用户，具体语法如下:

GRANT READ[,WRITE] ON DIRECTORY directory TO username;

 

for example:

grant read, write on directory exp_dir to eygle;

 

此时用户eygle就拥有了对该目录的读写权限。

 

 

让我们看一个简单的测试:

SQL> create or replace directory UTL_FILE_DIR as '/opt/oracle/utl_file';

Directory created.

SQL> declare

  2    fhandle utl_file.file_type;

  3  begin

  4    fhandle := utl_file.fopen('UTL_FILE_DIR', 'example.txt', 'w');

  5    utl_file.put_line(fhandle , 'eygle test write one');

  6    utl_file.put_line(fhandle , 'eygle test write two');

  7    utl_file.fclose(fhandle);

  8  end;

  9  /

 

PL/SQL procedure successfully completed.

 

SQL> !

[oracle@jumper 9.2.0]$ more /opt/oracle/utl_file/example.txt

eygle test write one

eygle test write two

[oracle@jumper 9.2.0]$

 

 

类似的我们可以通过utl_file来读取文件:

 

 

SQL> declare

  2    fhandle   utl_file.file_type;

  3    fp_buffer varchar2(4000);

  4  begin

  5    fhandle := utl_file.fopen ('UTL_FILE_DIR','example.txt', 'R');

  6 

  7    utl_file.get_line (fhandle , fp_buffer );

  8    dbms_output.put_line(fp_buffer );

  9    utl_file.get_line (fhandle , fp_buffer );

 10    dbms_output.put_line(fp_buffer );

 11    utl_file.fclose(fhandle);

 12  end;

 13  /

eygle test write one

eygle test write two

 

PL/SQL procedure successfully completed.

 

 

可以查询dba_directories查看所有directory.