关键字和保留字

关键字在 SQL 中有特殊的意义，例如 SELECT，UPDATE，DELETE，在作为表名跟函数名的时候，需要特殊对待，例如作为表名，保留字需要被反引号包住：

mysql> CREATE TABLE select (a INT);
ERROR 1105 (HY000): line 0 column 19 near " (a INT)" (total length 27)
mysql> CREATE TABLE `select` (a INT);
Query OK, 0 rows affected (0.09 sec)

BEGIN 和 END 是关键字，但不是保留字，所以不需要反引号：

mysql> CREATE TABLE `select` (BEGIN int, END int);
Query OK, 0 rows affected (0.09 sec)

有一种特殊情况，如果使用了限定符 .，那么也不需要用反引号：

mysql> CREATE TABLE test.select (BEGIN int, END int);
Query OK, 0 rows affected (0.08 sec)

下表列出了在 TiDB 中的关键字跟保留字，保留字用 ® 来标识：

ACTION	ADD ®	ADDDATE
ADMIN	AFTER	ALL ®
ALTER ®	ALWAYS	ANALYZE®
AND ®	ANY	AS ®
ASC ®	ASCII	AUTO_INCREMENT
AVG	AVG_ROW_LENGTH	BEGIN
BETWEEN ®	BIGINT ®	BINARY ®
BINLOG	BIT	BIT_XOR
BLOB ®	BOOL	BOOLEAN
BOTH ®	BTREE	BY ®
BYTE	CASCADE ®	CASE ®
CAST	CHANGE ®	CHAR ®
CHARACTER ®	CHARSET	CHECK ®
CHECKSUM	COALESCE	COLLATE ®
COLLATION	COLUMN ®	COLUMNS
COMMENT	COMMIT	COMMITTED
COMPACT	COMPRESSED	COMPRESSION
CONNECTION	CONSISTENT	CONSTRAINT ®
CONVERT ®	COUNT	CREATE ®
CROSS ®	CURRENT_DATE ®	CURRENT_TIME ®
CURRENT_TIMESTAMP ®	CURRENT_USER ®	CURTIME
DATA	DATABASE ®	DATABASES ®
DATE	DATE_ADD	DATE_SUB
DATETIME	DAY	DAY_HOUR ®
DAY_MICROSECOND ®	DAY_MINUTE ®	DAY_SECOND ®
DDL	DEALLOCATE	DEC
DECIMAL ®	DEFAULT ®	DELAY_KEY_WRITE
DELAYED ®	DELETE ®	DESC ®
DESCRIBE ®	DISABLE	DISTINCT ®
DISTINCTROW ®	DIV ®	DO
DOUBLE ®	DROP ®	DUAL ®
DUPLICATE	DYNAMIC	ELSE ®
ENABLE	ENCLOSED	END
ENGINE	ENGINES	ENUM
ESCAPE	ESCAPED	EVENTS
EXCLUSIVE	EXECUTE	EXISTS
EXPLAIN ®	EXTRACT	FALSE ®
FIELDS	FIRST	FIXED
FLOAT ®	FLUSH	FOR ®
FORCE ®	FOREIGN ®	FORMAT
FROM ®	FULL	FULLTEXT ®
FUNCTION	GENERATED ®	GET_FORMAT
GLOBAL	GRANT ®	GRANTS
GROUP ®	GROUP_CONCAT	HASH
HAVING ®	HIGH_PRIORITY ®	HOUR
HOUR_MICROSECOND ®	HOUR_MINUTE ®	HOUR_SECOND ®
IDENTIFIED	IF ®	IGNORE ®
IN ®	INDEX ®	INDEXES
INFILE ®	INNER ®	INSERT ®
INT ®	INTEGER ®	INTERVAL ®
INTO ®	IS ®	ISOLATION
JOBS	JOIN ®	JSON
KEY ®	KEY_BLOCK_SIZE	KEYS ®
KILL ®	LEADING ®	LEFT ®
LESS	LEVEL	LIKE ®
LIMIT ®	LINES ®	LOAD ®
LOCAL	LOCALTIME ®	LOCALTIMESTAMP ®
LOCK ®	LONGBLOB ®	LONGTEXT ®
LOW_PRIORITY ®	MAX	MAX_ROWS
MAXVALUE ®	MEDIUMBLOB ®	MEDIUMINT ®
MEDIUMTEXT ®	MICROSECOND	MIN
MIN_ROWS	MINUTE	MINUTE_MICROSECOND ®
MINUTE_SECOND ®	MIN	MIN_ROWS
MINUTE	MINUTE_MICROSECOND	MINUTE_SECOND
MOD ®	MODE	MODIRY
MONTH	NAMES	NATIONAL
NATURAL ®	NO	NO_WRITE_TO_BINLOG ®
NONE	NOT ®	NOW
NULL ®	NUMERIC ®	NVARCHAR ®
OFFSET	ON ®	ONLY
OPTION ®	OR ®	ORDER ®
OUTER ®	PARTITION ®	PARTITIONS
PASSWORD	PLUGINS	POSITION
PRECISION ®	PREPARE	PRIMARY ®
PRIVILEGES	PROCEDURE ®	PROCESS
PROCESSLIST	QUARTER	QUERY
QUICK	RANGE ®	READ ®
REAL ®	REDUNDANT	REFERENCES ®
REGEXP ®	RENAME ®	REPEAT ®
REPEATABLE	REPLACE ®	RESTRICT ®
REVERSE	REVOKE ®	RIGHT ®
RLIKE ®	ROLLBACK	ROW
ROW_COUNT	ROW_FORMAT	SCHEMA
SCHEMAS	SECOND	SECOND_MICROSECOND ®
SELECT ®	SERIALIZABLE	SESSION
SET ®	SHARE	SHARED
SHOW ®	SIGNED	SMALLINT ®
SNAPSHOT	SOME	SQL_CACHE
SQL_CALC_FOUND_ROWS ®	SQL_NO_CACHE	START
STARTING ®	STATS	STATS_BUCKETS
STATS_HISTOGRAMS	STATS_META	STATS_PERSISTENT
STATUS	STORED ®	SUBDATE
SUBSTR	SUBSTRING	SUM
SUPER	TABLE ®	TABLES
TERMINATED ®	TEXT	THAN
THEN ®	TIDB	TIDB_INLJ
TIDB_SMJ	TIME	TIMESTAMP
TIMESTAMPADD	TIMESTAMPDIFF	TINYBLOB ®
TINYINT ®	TINYTEXT ®	TO ®
TRAILING ®	TRANSACTION	TRIGGER ®
TRIGGERS	TRIM	TRUE ®
TRUNCATE	UNCOMMITTED	UNION ®
UNIQUE ®	UNKNOWN	UNLOCK ®
UNSIGNED ®	UPDATE ®	USE ®
USER	USING ®	UTC_DATE ®
UTC_TIME ®	UTC_TIMESTAMP ®	VALUE
VALUES ®	VARBINARY ®	VARCHAR ®
VARIABLES	VIEW	VIRTUAL ®
WARNINGS	WEEK	WHEN ®
WHERE ®	WITH ®	WRITE ®
XOR ®	YEAR	YEAR_MONTH ®
ZEROFILL ®