Delete an Oracle Database

$ sqlplus "/ as sysdba"

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.

SQL> startup mount exclusive
ORACLE instance started.

Total System Global Area  285212672 bytes
Fixed Size                  1218992 bytes
Variable Size             100664912 bytes
Database Buffers          180355072 bytes
Redo Buffers                2973696 bytes
Database mounted.

SQL> alter system enable restricted session;

System altered.

SQL> drop database;

SQL> exit

List a column and use it to make an operation with TSQL

DECLARE @tags varchar(200)
DECLARE @K int
SET @K=1

DECLARE MyCursor CURSOR
FOR
   SELECT columns
   FROM table

OPEN MyCursor

-- read the first record
FETCH MyCursor INTO @tags

-- loop
WHILE @@fetch_Status = 0
BEGIN
   INSERT INTO table2 (id, new_tags) VALUES
		(@K, @tags);
   SET @K = @K + 1;
-- read next record
   FETCH MyCursor INTO @tags
END

CLOSE myCursor

DEALLOCATE myCursor

Source : http://sqlpro.developpez.com/cours/sqlserver/transactsql/