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  • 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';

    本案例具体创建如下:


    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;

    例如:
    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.

    SQL> select * from dba_directories;

    OWNER                          DIRECTORY_NAME                 DIRECTORY_PATH
    ------------------------------ ------------------------------ ------------------------------
    SYS                            UTL_FILE_DIR                   /opt/oracle/utl_file
    SYS                            BDUMP_DIR                      /opt/oracle/admin/conner/bdump
    SYS                            EXP_DIR                        /opt/oracle/utl_file

    可以使用drop directory删除这些路径.

    SQL> drop directory exp_dir;

    Directory dropped

    SQL> select * from dba_directories;

    OWNER                          DIRECTORY_NAME                 DIRECTORY_PATH
    ------------------------------ ------------------------------ ------------------------------
    SYS                            UTL_FILE_DIR                   /opt/oracle/utl_file
    SYS                            BDUMP_DIR                      /opt/oracle/admin/conner/bdump

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  • 原文地址:https://www.cnblogs.com/advocate/p/1957542.html
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