Oracle Reserved Words

The following words are reserved by Oracle. That is, they have a special meaning to Oracle and so cannot be redefined. For this reason, you cannot use them to name database objects such as columns, tables, or indexes.

Oracle Reserved Words
ACCESS	ELSE	MODIFY	START
ADD	EXCLUSIVE	NOAUDIT	SELECT
ALL	EXISTS	NOCOMPRESS	SESSION
ALTER	FILE	NOT	SET
AND	FLOAT	NOTFOUND	SHARE
ANY	FOR	NOWAIT	SIZE
ARRAYLEN	FROM	NULL	SMALLINT
AS	GRANT	NUMBER	SQLBUF
ASC	GROUP	OF	SUCCESSFUL
AUDIT	HAVING	OFFLINE	SYNONYM
BETWEEN	IDENTIFIED	ON	SYSDATE
BY	IMMEDIATE	ONLINE	TABLE
CHAR	IN	OPTION	THEN
CHECK	INCREMENT	OR	TO
CLUSTER	INDEX	ORDER	TRIGGER
COLUMN	INITIAL	PCTFREE	UID
COMMENT	INSERT	PRIOR	UNION
COMPRESS	INTEGER	PRIVILEGES	UNIQUE
CONNECT	INTERSECT	PUBLIC	UPDATE
CREATE	INTO	RAW	USER
CURRENT	IS	RENAME	VALIDATE
DATE	LEVEL	RESOURCE	VALUES
DECIMAL	LIKE	REVOKE	VARCHAR
DEFAULT	LOCK	ROW	VARCHAR2
DELETE	LONG	ROWID	VIEW
DESC	MAXEXTENTS	ROWLABEL	WHENEVER
DISTINCT	MINUS	ROWNUM	WHERE
DROP	MODE	ROWS	WITH

Oracle Keywords

The following words also have a special meaning to Oracle but are not reserved words and so can be redefined. However, some might eventually become reserved words.

Oracle Keywords
ADMIN	CURSOR	FOUND	MOUNT
AFTER	CYCLE	FUNCTION	NEXT
ALLOCATE	DATABASE	GO	NEW
ANALYZE	DATAFILE	GOTO	NOARCHIVELOG
ARCHIVE	DBA	GROUPS	NOCACHE
ARCHIVELOG	DEC	INCLUDING	NOCYCLE
AUTHORIZATION	DECLARE	INDICATOR	NOMAXVALUE
AVG	DISABLE	INITRANS	NOMINVALUE
BACKUP	DISMOUNT	INSTANCE	NONE
BEGIN	DOUBLE	INT	NOORDER
BECOME	DUMP	KEY	NORESETLOGS
BEFORE	EACH	LANGUAGE	NORMAL
BLOCK	ENABLE	LAYER	NOSORT
BODY	END	LINK	NUMERIC
CACHE	ESCAPE	LISTS	OFF
CANCEL	EVENTS	LOGFILE	OLD
CASCADE	EXCEPT	MANAGE	ONLY
CHANGE	EXCEPTIONS	MANUAL	OPEN
CHARACTER	EXEC	MAX	OPTIMAL
CHECKPOINT	EXPLAIN	MAXDATAFILES	OWN
CLOSE	EXECUTE	MAXINSTANCES	PACKAGE
COBOL	EXTENT	MAXLOGFILES	PARALLEL
COMMIT	EXTERNALLY	MAXLOGHISTORY	PCTINCREASE
COMPILE	FETCH	MAXLOGMEMBERS	PCTUSED
CONSTRAINT	FLUSH	MAXTRANS	PLAN
CONSTRAINTS	FREELIST	MAXVALUE	PLI
CONTENTS	FREELISTS	MIN	PRECISION
CONTINUE	FORCE	MINEXTENTS	PRIMARY
CONTROLFILE	FOREIGN	MINVALUE	PRIVATE
COUNT	FORTRAN	MODULE	PROCEDURE
PROFILE	SAVEPOINT	SQLSTATE	TRACING
QUOTA	SCHEMA	STATEMENT_ID	TRANSACTION
READ	SCN	STATISTICS	TRIGGERS
REAL	SECTION	STOP	TRUNCATE
RECOVER	SEGMENT	STORAGE	UNDER
REFERENCES	SEQUENCE	SUM	UNLIMITED
REFERENCING	SHARED	SWITCH	UNTIL
RESETLOGS	SNAPSHOT	SYSTEM	USE
RESTRICTED	SOME	TABLES	USING
REUSE	SORT	TABLESPACE	WHEN
ROLE	SQL	TEMPORARY	WRITE
ROLES	SQLCODE	THREAD	WORK
ROLLBACK	SQLERROR	TIME

PL/SQL Reserved Words

The following PL/SQL keywords may require special treatment when used in embedded SQL statements.

PL/SQL Reserved Words
ABORT	BETWEEN	CRASH	DIGITS
ACCEPT	BINARY_INTEGER	CREATE	DISPOSE
ACCESS	BODY	CURRENT	DISTINCT
ADD	BOOLEAN	CURRVAL	DO
ALL	BY	CURSOR	DROP
ALTER	CASE	DATABASE	ELSE
AND	CHAR	DATA_BASE	ELSIF
ANY	CHAR_BASE	DATE	END
ARRAY	CHECK	DBA	ENTRY
ARRAYLEN	CLOSE	DEBUGOFF	EXCEPTION
AS	CLUSTER	DEBUGON	EXCEPTION_INIT
ASC	CLUSTERS	DECLARE	EXISTS
ASSERT	COLAUTH	DECIMAL	EXIT
ASSIGN	COLUMNS	DEFAULT	FALSE
AT	COMMIT	DEFINITION	FETCH
AUTHORIZATION	COMPRESS	DELAY	FLOAT
AVG	CONNECT	DELETE	FOR
BASE_TABLE	CONSTANT	DELTA	FORM
BEGIN	COUNT	DESC	FROM
FUNCTION	NEW	RELEASE	SUM
GENERIC	NEXTVAL	REMR	TABAUTH
GOTO	NOCOMPRESS	RENAME	TABLE
GRANT	NOT	RESOURCE	TABLES
GROUP	NULL	RETURN	TASK
HAVING	NUMBER	REVERSE	TERMINATE
IDENTIFIED	NUMBER_BASE	REVOKE	THEN
IF	OF	ROLLBACK	TO
IN	ON	ROWID	TRUE
INDEX	OPEN	ROWLABEL	TYPE
INDEXES	OPTION	ROWNUM	UNION
INDICATOR	OR	ROWTYPE	UNIQUE
INSERT	ORDER	RUN	UPDATE
INTEGER	OTHERS	SAVEPOINT	USE
INTERSECT	OUT	SCHEMA	VALUES
INTO	PACKAGE	SELECT	VARCHAR
IS	PARTITION	SEPARATE	VARCHAR2
LEVEL	PCTFREE	SET	VARIANCE
LIKE	POSITIVE	SIZE	VIEW
LIMITED	PRAGMA	SMALLINT	VIEWS
LOOP	PRIOR	SPACE	WHEN
MAX	PRIVATE	SQL	WHERE
MIN	PROCEDURE	SQLCODE	WHILE
MINUS	PUBLIC	SQLERRM	WITH
MLSLABEL	RAISE	START	WORK
MOD	RANGE	STATEMENT	XOR
MODE	REAL	STDDEV
NATURAL	RECORD	SUBTYPE

C# Keywords

Keywords are predefined, reserved identifiers that have special meanings to the compiler. They cannot be used as identifiers in your program unless they include @ as a prefix. For example, @if is a valid identifier but if is not because if is a keyword.
The first table in this topic lists keywords that are reserved identifiers in any part of a C# program. The second table in this topic lists the contextual keywords in C#. Contextual keywords have special meaning only in a limited program context and can be used as identifiers outside that context. Generally, as new keywords are added to the C# language, they are added as contextual keywords in order to avoid breaking programs written in earlier versions.

abstract	as	base	bool
break	byte	case	catch
char	checked	class	const
continue	decimal	default	delegate
do	double	else	enum
event	explicit	extern	false
finally	fixed	float	for
foreach	goto	if	implicit
in	in (generic modifier)	int	interface
internal	is	lock	long
namespace	new	null	object
operator	out	out (generic modifier)	override
params	private	protected	public
readonly	ref	return	sbyte
sealed	short	sizeof	stackalloc
static	string	struct	switch
this	throw	true	try
typeof	uint	ulong	unchecked
unsafe	ushort	using	virtual
void	volatile	while

PHP Keywords

PHP Keywords

__halt_compiler()	abstract	and	array()	as
break	callable (as of PHP 5.4)	case	catch	class
clone	const	continue	declare	default
die()	do	echo	else	elseif
empty()	enddeclare	endfor	endforeach	endif
endswitch	endwhile	eval()	exit()	extends
final	for	foreach	function	global
goto (as of PHP 5.3)	if	implements	include	include_once
instanceof	insteadof (as of PHP 5.4)	interface	isset()	list()
namespace (as of PHP 5.3)	new	or	print	private
protected	public	require	require_once	return
static	switch	throw	trait (as of PHP 5.4)	try
unset()	use	var	while	xor

Visual Basic Language Keywords

The following table contains a listing of the Visual Basic .NET language keywords. All language keywords are reserved.

AddHandler	AddressOf	Alias	And
AndAlso	Ansi	As	Assembly
Auto	Boolean	ByRef	Byte
ByVal	Call	Case	Catch
CBool	CByte	CChar	CDate
CDec	CDbl	Char	CInt
Class	CLng	CObj	Const
CShort	CSng	CStr	CType
Date	Decimal	Declare	Default
Delegate	Dim	DirectCast	Do
Double	Each	Else	ElseIf
End	Enum	Erase	Error
Event	Exit	False	Finally
For	Friend	Function	Get
GetType	GoSub	GoTo	Handles
If	Implements	Imports	In
Inherits	Integer	Interface	Is
Let	Lib	Like	Long
Loop	Me	Mod	Module
MustInherit	MustOverride	MyBase	MyClass
Namespace	New	Next	Not
Nothing	NotInheritable	NotOverridable	Object
On	Option	Optional	Or
OrElse	Overloads	Overridable	Overrides
ParamArray	Preserve	Private	Property
Protected	Public	RaiseEvent	ReadOnly
ReDim	REM	RemoveHandler	Resume
Return	Select	Set	Shadows
Shared	Short	Single	Static
Step	Stop	String	Structure
Sub	SyncLock	Then	Throw
To	True	Try	TypeOf
Unicode	Until	Variant	When
While	With	WithEvents	WriteOnly
Xor	#Const	#ExternalSource	#If...Then...#Else
#Region	-	&	&=
*	*=	/	/=
\	\=	^	^=
+	+=	=	-=

Note   GoSub, Let, and Variant are retained as keywords, although they are no longer used in Visual Basic .NET.