Introduction
to Oracle Datatypes
Each
column value and constant in a SQL statement has a data type, which is
associated with a specific storage format, constraints, and a valid range of
values. When you create a table, you must specify a datatype for each of its
columns.
- Overview of Character Datatypes
- Overview of Numeric Datatypes
- Overview of DATE Datatype
- Overview of LOB Datatypes
- Overview of RAW and LONG RAW Datatypes
- Overview of ROWID and UROWID Datatypes
The following sections that describe each of the built-in
datatypes in more detail.
Overview of Character Datatypes
The
character datatypes store character (alphanumeric) data in strings, with byte
values corresponding to the character encoding scheme, generally called a
character set or code page.
The database's character set
is established when you create the database. Examples of character sets are
7-bit ASCII (American Standard Code for Information Interchange), EBCDIC
(Extended Binary Coded Decimal Interchange Code), Code Page 500, Japan Extended
UNIX, and Unicode UTF-8. Oracle supports both
single-byte and multibyte encoding schemes.
This section includes the
following topics:
· CHAR
Datatype
· VARCHAR2
and VARCHAR Datatypes
· Length
Semantics for Character Datatypes
· NCHAR
and NVARCHAR2 Datatypes
· Use
of Unicode Data in Oracle Database
· LOB
Character Datatypes
· LONG
Datatype
