Oracle Data Types

1. Each value manipulated by Oracle Database has a data type.
2.  The data type of a value associates a fixed set of properties with the value.
3. These properties cause Oracle to treat values of one data type differently from values of another. For example, you can add values of NUMBER data type, but not values of CHAR data type. 
4. When you create a table, you must specify a data type for each of its columns. 
5. These data types define the domain of values that each column can contain, or each argument can have. For example, DATE columns cannot accept the value February 29 (except for a leap year) or the values 2 or 'SHOE'. 
6. For example, if you insert '01-JAN-98' into a DATE column, then Oracle treats the
   '01-JAN-98' character string as a DATE value after verifying that it translates to a valid
   date.

7. Data Types

   1. String / Char Data Types
   2. Numeric Data Types
   3. Date Data Types
   4. Binary Data Types
   String / Char Data types
   1. Char (Size)
   2. Varchar2(Size)
   3. Nvarchar2(Size)
   4. Nchar(Size)
   5. Long

   Numeric Data types

   1. Number(Precesion)
   2. Number(Precesion, [Scale])

   DATE data types

   1. Date

   Binary Data types

   1. Raw(Size)
   2. Long Raw(Size)
   3. Lob--Large Objects
   •   Clob
   •   Blob
   •  Nclob