关键字

SQL里有保留字和非保留字之分。根据标准，保留字决不能用做其他标识符。非保留字只是在特定的环境里有特殊的含义，而在其他环境里是可以用做标识符的。

标识符的命名需要遵守如下规范：

• 标识符需要为字母、下划线、数字（0-9）或美元符号（$）。

• 标识符必须以字母（a-z）或下划线（_）开头。

  说明:

  • 此命名规范为建议项，非强制项。
  • 特殊情况下可以使用双引号规避特殊字符报错。

表 1 SQL关键字

关键字	MogDB
ALL	reserved
ANALYSE	reserved
ANALYZE	reserved
AND	reserved
ANY	reserved
ARRAY	reserved
AS	reserved
ASC	reserved
ASYMMETRIC	reserved
AUTHID	reserved
AUTHORIZATION	type-func-name
BETWEEN	col-name
BIGINT	col-name
BINARY	type-func-name
BINARY_DOUBLE	col-name
BINARY_FLOAT	col-name
BINARY_INTEGER	col-name
BIT	col-name
BOOLEAN	col-name
BOTH	reserved
BUCKETCNT	col-name
BUCKETS	reserved
BYTEAWITHOUTORDER	col-name
BYTEAWITHOUTORDERWITHEQUAL	col-name
CASE	reserved
CAST	reserved
CHAR	col-name
CHARACTER	col-name
CHECK	reserved
COALESCE	col-name
COLLATE	reserved
COLLATION	type-func-name
COLUMN	reserved
COMPACT	type-func-name
CONCURRENTLY	type-func-name
CONSTRAINT	reserved
CREATE	reserved
CROSS	type-func-name
CSN	type-func-name
CURRENT_CATALOG	reserved
CURRENT_DATE	reserved
CURRENT_ROLE	reserved
CURRENT_SCHEMA	type-func-name
CURRENT_TIME	reserved
CURRENT_TIMESTAMP	reserved
CURRENT_USER	reserved
DATE	col-name
DEC	col-name
DECIMAL	col-name
DECODE	col-name
DEFAULT	reserved
DEFERRABLE	reserved
DELTAMERGE	type-func-name
DESC	reserved
DISTINCT	reserved
DO	reserved
ELSE	reserved
END	reserved
EXCEPT	reserved
EXCLUDED	reserved
EXISTS	col-name
EXTRACT	col-name
FALSE	reserved
FENCED	reserved
FETCH	reserved
FLOAT	col-name
FOR	reserved
FOREIGN	reserved
FREEZE	type-func-name
FROM	reserved
FULL	type-func-name
GRANT	reserved
GREATEST	col-name
GROUP	reserved
GROUPING	col-name
GROUPPARENT	reserved
HAVING	reserved
HDFSDIRECTORY	type-func-name
ILIKE	type-func-name
IN	reserved
INITIALLY	reserved
INNER	type-func-name
INOUT	col-name
INT	col-name
INTEGER	col-name
INTERSECT	reserved
INTERVAL	col-name
INTO	reserved
IS	reserved
JOIN	type-func-name
LEADING	reserved
LEAST	col-name
LEFT	type-func-name
LESS	reserved
LIKE	type-func-name
LIMIT	reserved
LOCALTIME	reserved
LOCALTIMESTAMP	reserved
MAXVALUE	reserved
MINUS	reserved
MODIFY	reserved
NATIONAL	col-name
NATURAL	type-func-name
NCHAR	col-name
NLSSORT	reserved
NONE	col-name
NOT	reserved
NOTNULL	type-func-name
NULL	reserved
NULLIF	col-name
NUMBER	col-name
NUMERIC	col-name
NVARCHAR2	col-name
NVL	col-name
OFFSET	reserved
ON	reserved
ONLY	reserved
OR	reserved
ORDER	reserved
OUT	col-name
OUTER	type-func-name
OVERLAPS	type-func-name
OVERLAY	col-name
PERFORMANCE	reserved
PLACING	reserved
POSITION	col-name
PRECISION	col-name
PRIMARY	reserved
PROCEDURE	reserved
REAL	col-name
RECYCLEBIN	type-func-name
REFERENCES	reserved
REJECT	reserved
RETURNING	reserved
RIGHT	type-func-name
ROW	col-name
ROWNUM	reserved
SELECT	reserved
SESSION_USER	reserved
SETOF	col-name
SIMILAR	type-func-name
SMALLDATETIME	col-name
SMALLINT	col-name
SOME	reserved
SUBSTRING	col-name
SYMMETRIC	reserved
SYSDATE	reserved
SYSTIMESTAMP	reserved
TABLE	reserved
TABLESAMPLE	type-func-name
THEN	reserved
TIME	col-name
TIMECAPSULE	type-func-name
TIMESTAMP	col-name
TIMESTAMPDIFF	col-name
TINYINT	col-name
TO	reserved
TRAILING	reserved
TREAT	col-name
TRIM	col-name
TRUE	reserved
UNION	reserved
UNIQUE	reserved
USER	reserved
USING	reserved
VALUES	col-name
VARCHAR	col-name
VARCHAR2	col-name
VARIADIC	reserved
VERBOSE	type-func-name
VERIFY	reserved
WHEN	reserved
WHERE	reserved
WINDOW	reserved
WITH	reserved
XMLATTRIBUTES	col-name
XMLCONCAT	col-name
XMLELEMENT	col-name
XMLEXISTS	col-name
XMLFOREST	col-name
XMLPARSE	col-name
XMLPI	col-name
XMLROOT	col-name
XMLSERIALIZE	col-name