Reserved keywords in Oracle

Oracle official documentation:

Reserved words and keywordsare identifiers that have special meaning in PL/SQL.

You cannot use reserved words as ordinary user-defined identifiers. you can use them as quoted user-defined identifiers, but it is not recommended. for more information, see "QuotedUser-Defined Identifiers ".

You can use keywords as ordinary user-defined identifiers, but it is not recommended.

Reserved Words cannot be used as User-Defined variables. However, you can add double quotation marks, but do not store them.

Keywords can be used as User-Defined variables without being pushed.

For example:

(1) Reserved Words

-- Number

Create a table as the field name.

SQL> CREATE TABLE cux_oyj_RESERVED_WORDS (NUMBER );

Create table cux_oyj_RESERVED_WORDS (NUMBER)

ORA-00904: The identifier is invalid.

You can add double quotation marks

SQL> CREATE TABLE cux_oyj_RESERVED_WORDS ("NUMBER" NUMBER );

Table created

But query:

SQL> SELECT rw. number from cux_oyj_RESERVED_WORDS rw;

SELECT rw. number from cux_oyj_RESERVED_WORDS rw

ORA-01747: user. table. column, table. column or column description invalid

It is troublesome to use.

(2) KEYWORDS

-- Name

Create a table as the field name.

SQL> CREATE TABLE cux_oyj_KEYWORDS (NAME VARCHAR2 (50 ));

Table created

View of Reserved Words and keywords (Dynamic View) V $ RESERVED_WORDS

This view gives a list of all SQL keywords. To determine whether a participant keyword is reserved in any way, check the RESERVED, RES_TYPE, RES_ATTR, and RES_SEMI columns.

Column	Datatype	Description
KEYWORD	VARCHAR2(30)	Name of the keyword
LENGTH	NUMBER	Length of the keyword
RESERVED	VARCHAR2(1)	A value of Y means that the keyword cannot be used as an identifier. A value of N means that it is not reserved.
RES_TYPE	VARCHAR2(1)	A value of Y means that the keyword cannot be used as a type name. A value of N means that it is not reserved.
RES_ATTR	VARCHAR2(1)	A value of Y means that the keyword cannot be used as an attribute name. A value of N means that it is not reserved.
RES_SEMI	VARCHAR2(1)	A value of Y means that the keyword is not allowed as an identifier in certain situations, such as in DML. A value of N means that it is not reserved.
DUPLICATE	VARCHAR2(1)	A value of Y means that the keyword is a duplicate of another keyword. A value of N means that it is not a duplicate.

Reserved Words:

Begins:	Reserved Words
A	ALL, ALTER, AND, ANY, AS, ASC,
B	BEGIN, BETWEEN,
C	CASE, CHECK, CLUSTERS, CLUSTER, COLAUTH, COLUMNS, COMPRESS, CONNECT, CRASH, CREATE, CURSOR
D	DECLARE, DEFAULT, DESC, DISTINCT, DROP
E	ELSE, END, EXCEPTION, EXCLUSIVE
F	FETCH, FOR, FROM, FUNCTION
G	GOTO, GRANT, GROUP
H	HAVING
I	IDENTIFIED, IF, IN, INDEX, INDEXES, INSERT, INTERSECT, INTO, IS
L	LIKE, LOCK
M	MINUS, MODE
N	NOCOMPRESS, NOT, NOWAIT, NULL
O	OF, ON, OPTION, OR, ORDER, OVERLAPS
P	PROCEDURE, PUBLIC
R	RESOURCE, REVOKE
S	SELECT, SHARE, SIZE, SQL, START, SUBTYPE
T	TABAUTH, TABLE, THEN, TO, TYPE
U	UNION, UNIQUE, UPDATE
V	VALUES, VIEW, VIEWS
W	WHEN, WHERE,

Keywords:

Begins:	Keywords
A	A, ADD, AGENT, AGGREGATE, ARRAY, ATTRIBUTE, AUTHID, AVG
B	BFILE_BASE, BINARY, BLOB_BASE, BLOCK, BODY, BOTH, BOUND, BULK, BYTE
C	C, CALL, CALLING, CASCADE, CHAR, CHAR_BASE, CHARACTER, CHARSET, CHARSETFORM, CHARSETID, CLOB_BASE, CLOSE, COLLECT, COMMENT, COMMIT, COMMITTED, COMPILED, CONSTANT, CONSTRUCTOR, CONTEXT, CONTINUE, CONVERT, COUNT, CURRENT, CUSTOMDATUM
D	DANGLING, DATA, DATE, DATE_BASE, DAY, DEFINE, DELETE, DETERMINISTIC, DOUBLE, DURATION
E	ELEMENT, ELSIF, EMPTY, ESCAPE, escape t, EXCEPTIONS, EXECUTE, EXISTS, EXIT, EXTERNAL
F	FINAL, FIXED, FLOAT, FORALL, FORCE
G	GENERAL
H	HASH, HEAP, HIDDEN, HOUR
I	IMMEDIATE, INCLUDING, INDICATOR, INDICES, INFINITE, INSTANTIABLE, INT, INTERFACE, INTERVAL, INVALIDATE, ISOLATION
J	JAVA
L	LANGUAGE, LARGE, LEADING, LENGTH, LEVEL, LIBRARY, LIKE2, LIKE4, LIKEC, LIMIT, LIMITED, LOCAL, LONG, LOOP
M	MAP, MAX, MAXLEN, MEMBER, MERGE, MIN, MINUTE, MOD, MODIFY, MONTH, MULTISET
N	NAME, NAN, NATIONAL, NATIVE, NCHAR, NEW, NOCOPY, NUMBER_BASE
O	OBJECT, OCICOLL, OCIDATE, OCIDATETIME, OCIDURATION, OCIINTERVAL, interval, OCINUMBER, OCIRAW, OCIREF, region, OCIROWID, OCISTRING, OCITYPE, OLD, ONLY, OPAQUE, OPEN, OPERATOR, ORACLE, ORADATA, ORGANIZATION, ORLANY, ORLVARY, OTHERS, OUT, OVERRIDING
P	PACKAGE, PARALLEL_ENABLE, PARAMETER, PARAMETERS, PARENT, PARTITION, PASCAL, PIPE, PIPELINED, PRAGMA, PRECISION, PRIOR, PRIVATE
R	RAISE, RANGE, RAW, READ, RECORD, REF, REFERENCE, RELIES_ON, REM, REMAINDER, RENAME, RESULT, RESULT_CACHE, RETURN, RETURNING, REVERSE, ROLLBACK, ROW
S	SAMPLE, SAVE, SAVEPOINT, SB1, SB2, SB4, SECOND, SEGMENT, SELF, SEPARATE, SEQUENCE, SERIALIZABLE, SET, SHORT, SIZE_T, SOME, SPARSE, SQLCODE, SQLDATA, SQLNAME, SQLSTATE, STANDARD, STATIC, STDDEV, STORED, STRING, STRUCT, STYLE, SUBMULTISET, SUBPARTITION, SUBSTITUTABLE, SUM, SYNONYM
T	TDO, THE, TIME, TIMESTAMP, TIMEZONE_ABBR, TIMEZONE_HOUR, TIMEZONE_MINUTE, TIMEZONE_REGION, TRAILING, TRANSACTION, TRANSACTIONAL, TRUSTED
U	UB1, UB2, UB4, UNDER, UNSIGNED, UNTRUSTED, USE, USING
V	VALIST, VALUE, VARIABLE, VARIANCE, VARRAY, VARYING, VOID
W	WHILE, WORK, WRAPPED, WRITE
Y	YEAR
Z	ZONE