ANYDATA介紹

ANYDATA特殊列，屬于Oracle内建列，對于Oracle資料庫，每一個值都是一種資料類型。當使用者建立表或聚簇時，需要為每一個列指定對應的資料類型。即使是建立存儲過程或函數的時，一樣需要為參數指定相應的資料類型。

一個資料類型可以是标量的或非标量的，标的包含一個原子值，非标量的（有時成為集合）包含一個集合值。LOB(Large Object)就是一個特殊形式的标量資料類型表示大量的标量、二進制或字元資料，

Oracle内建資料類型可分為如下幾類：

Oracle中通過Code代碼來指代相應的資料類型，如下表所示：

Table 2-1 Built-in Data Type Summary

Code	Data Type	Description
1	VARCHAR2 ( size  [ BYTE  |  CHAR ])	Variable-length character string having maximum length  size  bytes or characters. You must specify  size  for  VARCHAR2 . Minimum  size  is 1 byte or 1 character. Maximum size is: 32767 bytes or characters if MAX_STRING_SIZE = EXTENDED 4000 bytes or characters if MAX_STRING_SIZE = STANDARD Refer to "Extended Data Types" for more information on the  MAX_STRING_SIZE initialization parameter. BYTE  indicates that the column will have byte length semantics.  CHAR  indicates that the column will have character semantics.
	NVARCHAR2 size )	Variable-length Unicode character string having maximum length  size  characters. You must specify  size NVARCHAR2 . The number of bytes can be up to two times size AL16UTF16  encoding and three times  size UTF8  encoding. Maximum size  is determined by the national character set definition, with an upper limit of: 32767 bytes if  MAX_STRING_SIZE = EXTENDED 4000 bytes if  MAX_STRING_SIZE = STANDARD MAX_STRING_SIZE
2	NUMBER  [ ( p  [,  s ]) ]	Number having precision  p  and scale  s . The precision  p  can range from 1 to 38. The scale  s  can range from -84 to 127. Both precision and scale are in decimal digits. A NUMBER  value requires from 1 to 22 bytes.
	FLOAT  [( p )]	A subtype of the  NUMBER  data type having precision  p . A  FLOAT  value is represented internally as  NUMBER p  can range from 1 to 126 binary digits. A  FLOAT value requires from 1 to 22 bytes.
8	LONG	Character data of variable length up to 2 gigabytes, or 231 -1 bytes. Provided for backward compatibility.
12	DATE	Valid date range from January 1, 4712 BC, to December 31, 9999 AD. The default format is determined explicitly by the NLS_DATE_FORMAT  parameter or implicitly by the  NLS_TERRITORY  parameter. The size is fixed at 7 bytes. This data type contains the datetime fields  YEAR ,  MONTH DAY HOUR , MINUTE , and  SECOND . It does not have fractional seconds or a time zone.
100	BINARY_FLOAT	32-bit floating point number. This data type requires 4 bytes.
101	BINARY_DOUBLE	64-bit floating point number. This data type requires 8 bytes.
180	TIMESTAMP [( fractional_seconds_precision	Year, month, and day values of date, as well as hour, minute, and second values of time, where  fractional_seconds_precision  is the number of digits in the fractional part of the  SECOND  datetime field. Accepted values of  fractional_seconds_precision  are 0 to 9. The default is 6. The default format is determined explicitly by the NLS_TIMESTAMP_FORMAT NLS_TERRITORY  parameter. The size is 7 or 11 bytes, depending on the precision. This data type contains the datetime fields  YEAR MONTH DAY HOUR MINUTE SECOND . It contains fractional seconds but does not have a time zone.
181	TIMESTAMP fractional_seconds_precision )]  WITH TIME ZONE	All values of  TIMESTAMP  as well as time zone displacement value, where fractional_seconds_precision  is the number of digits in the fractional part of the SECOND  datetime field. Accepted values are 0 to 9. The default is 6. The default format is determined explicitly by the NLS_TIMESTAMP_FORMAT NLS_TERRITORY  parameter. The size is fixed at 13 bytes. This data type contains the datetime fields  YEAR MONTH DAY HOUR MINUTE SECOND TIMEZONE_HOUR TIMEZONE_MINUTE . It has fractional seconds and an explicit time zone.
231	TIMESTAMP fractional_seconds_precision WITH LOCAL TIME ZONE	TIMESTAMP WITH TIME ZONE , with the following exceptions: Data is normalized to the database time zone when it is stored in the database. When the data is retrieved, users see the data in the session time zone. The default format is determined explicitly by the  NLS_TIMESTAMP_FORMAT NLS_TERRITORY parameter. The size is 7 or 11 bytes, depending on the precision.
182	INTERVAL YEAR year_precision TO MONTH	Stores a period of time in years and months, where  year_precision  is the number of digits in the  YEAR  datetime field. Accepted values are 0 to 9. The default is 2. The size is fixed at 5 bytes.
183	INTERVAL DAY day_precision TO SECOND fractional_seconds_precision	Stores a period of time in days, hours, minutes, and seconds, where day_precision  is the maximum number of digits in the  DAY  datetime field. Accepted values are 0 to 9. The default is 2. fractional_seconds_precision is the number of digits in the fractional part of the  SECOND  field. Accepted values are 0 to 9. The default is 6. The size is fixed at 11 bytes.
23	RAW size	Raw binary data of length  size  bytes. You must specify  size  for a  RAW  value. Maximum  size  is: MAX_STRING_SIZE = EXTENDED 2000 bytes if  MAX_STRING_SIZE = STANDARD MAX_STRING_SIZE
24	LONG RAW	Raw binary data of variable length up to 2 gigabytes.
69	ROWID	Base 64 string representing the unique address of a row in its table. This data type is primarily for values returned by the  ROWID pseudocolumn.
208	UROWID size	Base 64 string representing the logical address of a row of an index-organized table. The optional  size  is the size of a column of type  UROWID . The maximum size and default is 4000 bytes.
96	CHAR size BYTE CHAR ])]	Fixed-length character data of length  size bytes or characters. Maximum  size  is 2000 bytes or characters. Default and minimum size  is 1 byte. BYTE  and  CHAR  have the same semantics as for  VARCHAR2 .
	NCHAR size	size characters. The number of bytes can be up to two times  size AL16UTF16 size UTF8  encoding. Maximum  size  is determined by the national character set definition, with an upper limit of 2000 bytes. Default and minimum  size  is 1 character.
112	CLOB	A character large object containing single-byte or multibyte characters. Both fixed-width and variable-width character sets are supported, both using the database character set. Maximum size is (4 gigabytes - 1) * (database block size).
	NCLOB	A character large object containing Unicode characters. Both fixed-width and variable-width character sets are supported, both using the database national character set. Maximum size is (4 gigabytes - 1) * (database block size). Stores national character set data.
113	BLOB	A binary large object. Maximum size is (4 gigabytes - 1) * (database block size).
114	BFILE	Contains a locator to a large binary file stored outside the database. Enables byte stream I/O access to external LOBs residing on the database server. Maximum size is 4 gigabytes.

Any Types

Any類型用于處理未知的過程參數和表列的實際類型。該資料類型可以讓你動态的封裝和通路類型描述，資料執行個體和任何SQL類的執行個體資料集，這些類型由OCI和PL/SQL接口構造和通路

ANYTYPE

該類型包含一個對任何SQL類型的名或未命名的臨時類型的類型描述。

ANYDATA

該類型包含一個給定的類型執行個體，資料類型加描述，ANYDATA可以向表中列的資料類型那樣使用，并且将各種混雜的值存于該列之中。這些值可以是SQL内建類型和使用者定義類型。

ANYDATASET

該類型包含一個給定的類型描述加類型執行個體集，ANYDATASET可靈活的用于過程參數資料類型，這些值同樣可以是SQL内建類型和使用者定義類型。

資料類型的介紹：

http://docs.oracle.com/database/121/SQLRF/sql_elements001.htm#SQLRF0021