Oracle Data Types - NVARCHAR2

Versions: Oracle 11g, 10g, 9i, 8i and 7.3

Oracle - NVARCHAR2
Syntax	NVARCHAR2(n)
Data	Variable-length character data in Unicode - UTF-8 or UTF-16
Parameters	n is the maximum number of characters
Range	1 ⇐ n ⇐ 4000/charsize
Default	n is mandatory
Padding	Not right-padded with spaces to n
Trailing Spaces	Not removed when the value is stored and retrieved
Empty String	'' is treated as NULL
Error Handling	Error is raised if the value is too long
Storage Size	Actual entry length
Synonyms	NATIONAL VARCHAR, NATIONAL CHAR VARYING, NATIONAL CHARACTER VARYING
Standards	Oracle Extension

Oracle NVARCHAR2 - Equivalents in Other Databases

Database	Data Type and Conversion
SQL Server	NVARCHAR(n \| max), 1 ⇐ n ⇐ 8000, 2G if max is specified
MySQL	NVARCHAR(n), 1 ⇐ n ⇐ 21845, Unicode - UTF-8
PostgreSQL	VARCHAR(n), 1 ⇐ n ⇐ 1G
Sybase ASE	NVARCHAR(n), 1 ⇐ n ⇐ pagesize/@@ncharsize (page size is 2K, 4K, 8K or 16K); UNIVARCHAR(n), 1 ⇐ n ⇐ pagesize/@@unicharsize, Unicode
Informix	NVARCHAR(n,r), 1 ⇐ n ⇐ 255, LVARCHAR(n), 1 ⇐ n ⇐ 32739
HP Neoview	NVARCHAR(n), 1 ⇐ n ⇐ (32708 - size of other columns)
Ingres	NVARCHAR(n), 1 ⇐ n ⇐ 16000, Unicode - UTF-8; LONG NVARCHAR, 2G, Unicode - UTF-8

Related Data Types in Oracle

Data Types
Fixed-length Character Data	CHAR(n)	NCHAR(n)
Variable-length Character Data	VARCHAR2(n)
Character Large Objects	CLOB	NCLOB	LONG

All Data Types

Oracle

SQL Server

IBM DB2

MySQL

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Sybase ASA

Informix DS

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HP Neoview

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Ingres