Oracle Data Types - VARCHAR2

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

Oracle - VARCHAR2
Syntax	VARCHAR2(n [CHAR \| BYTE])
Data	Variable-length character data, single-byte and multibyte character sets
Parameters	n is the maximum number of bytes if BYTE is specified (default, defined by NLS_LENGTH_SEMANTICS) or characters if CHAR is specified
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
Character Set	Database default
Empty String	'' is treated as NULL
Error Handling	Error is raised if the value is too long
Storage Size	Actual entry length
Synonyms	VARCHAR, CHAR VARYING, CHARACTER VARYING
Version Differences	Oracle 9i - CHAR and BYTE qualifiers added
Standards	Oracle Extension

Oracle VARCHAR2 - Equivalents in Other Databases

Database	Data Type and Conversion
SQL Server	VARCHAR(n \| max), 1 ⇐ n ⇐ 8000, 2G if max is specified
MySQL	VARCHAR(n), 1 ⇐ n ⇐ 65535/charsize
PostgreSQL	VARCHAR(n), 1 ⇐ n ⇐ 1G
Sybase ASE	VARCHAR(n), 1 ⇐ n ⇐ pagesize (2K, 4K, 8K or 16K)
Informix	VARCHAR(n,r), 1 ⇐ n ⇐ 255, LVARCHAR(n), 1 ⇐ n ⇐ 32739
HP Neoview	VARCHAR(n), 1 ⇐ n ⇐ (32708 - size of other columns)
Ingres	VARCHAR(n), 1 ⇐ n ⇐ 32000

Related Data Types in Oracle

Data Types
Fixed-length Character Data	CHAR(n)	NCHAR(n)
Variable-length Character Data	NVARCHAR2(n)
Character Large Objects	CLOB	NCLOB	LONG

All Data Types

Oracle

SQL Server

IBM DB2

MySQL

PostgreSQL

Sybase ASE

Sybase ASA

Informix DS

Teradata

HP Neoview

Interbase/Firebird

Ingres