Sometimes you need to copy some OS file from one location to another. If you’re using only Sql*Plus and you can’t connect directly to OS, you can user Oracle’s UTL_FILE.FCOPY function to achieve this goal.

Firstly, we’ll create two directories and one file. Then we’ll create a user and copy this file from one folder to another using UTL_FILE package

[oracle@localhost /]$ cd /tmp
[oracle@localhost tmp]$ mkdir copy_dir
[oracle@localhost tmp]$ mkdir backup_dir
[oracle@localhost tmp]$ ls backup_dir/
[oracle@localhost tmp]$
[oracle@localhost tmp]$ cd copy_dir
[oracle@localhost copy_dir]$ vi test.dat (We are adding a line with word MY_TEST to file test.dat)
[oracle@localhost copy_dir]$ ls -lh
total 4.0K
-rw-r–r–  1 oracle oinstall 8 Dec  7 04:11 test.dat
[oracle@localhost copy_dir]$ cat test.dat
MY_TEST
[oracle@localhost copy_dir]$sqlplus “/ as sysdba”

SQL> CREATE USER kamran IDENTIFIED BY kamran;

User created.

SQL> grant connect, resource to kamran;

Grant succeeded.

SQL> grant create any directory to kamran;

Grant succeeded.

SQL> grant execute on utl_file to kamran;

Grant succeeded.

SQL> conn kamran/kamran
Connected.
SQL> create directory file_source as ‘/tmp/copy_dir’;

Directory created.
SQL> create directory backup_source as ‘/tmp/backup_dir’;

Directory created.

SQL> exec utl_file.fcopy(‘FILE_SOURCE’,’test.dat’,’BACKUP_SOURCE’,’copied_test.dat’);

PL/SQL procedure successfully completed.

SQL>exit
[oracle@localhost tmp]$ cd backup_dir/
[oracle@localhost backup_dir]$ ls -lh
total 4.0K
-rw-r–r–  1 oracle oinstall 8 Dec  7 04:32 copied_test.dat
[oracle@localhost backup_dir]$

Today I’ll show how we can make a table read only using database triggers

In this example, we’ll create a table, insert data in it, and then create trigger to prevent any insert, update or delete statement on table

SQL> CREATE TABLE tbl_read_only (id NUMBER);

Table created.

SQL> INSERT INTO tbl_read_only VALUES(1);

1 row created.

SQL> COMMIT;

Commit complete.

SQL> SELECT * FROM tbl_read_only;

        ID
———-
         1

SQL> CREATE TRIGGER trg_tbl_read_only BEFORE DELETE OR INSERT OR UPDATE
  2  ON tbl_read_only
  3  BEGIN
  4  RAISE_APPLICATION_ERROR(-20202,’Table Status: READ ONLY!!!’);
  5  END;
  6  /

Trigger created.

SQL> INSERT INTO tbl_read_only VALUES(2);
INSERT INTO tbl_read_only VALUES(2)
            *
ERROR at line 1:
ORA-20202: Table Status: READ ONLY!!!
ORA-06512: at “KAMRAN.TRG_TBL_READ_ONLY”, line 2
ORA-04088: error during execution of trigger ‘KAMRAN.TRG_TBL_READ_ONLY’
SQL>