Data Types

Data Types

Data Type:-Data types define the ways to identify the type of data and their associated operations. 

Types of Data Types :-There are 4 types of predefined data types explained as below

1) Scalar Data Types:- A scalar data type is an atomic data type that does not have any  
                                             internal components.
 Example:-
CHAR (fixed length character value between 1 and 32,767 characters)
VARCHAR2 (variable length character value between 1 and 32,767 characters)
NUMBER ( fixed-decimal, floating-decimal or integer values)
BOOLEAN ( logical data type for TRUE FALSE or NULL values)
DATE (stores date and time information)
LONG (character data of variable length)
 
2) Composite Data Types:- A composite data type is made up of other data types and  
                                                       internal components that can be easily used and manipulated.
Example:- Record, Associate Array, Nested Table and Varray.
 
3) Reference Data Types: A reference data types holds values, called pointers that designate to other program items or data items.  
Example:- %type, %rowtype
 
4) Large Object Data Types: A Large Object datatype holds values, called locators, that defines the location of large objects( such as video clips, graphic image) stored out of line.
Example:-
BFILE (Binary file)
BLOB (Binary large object)
CLOB ( Character large object)
NCLOB( NCHAR type large object)