关键字

本文介绍 TiDB 的关键字，对保留字和非保留字作出区分，并汇总所有的关键字以供查询使用。

关键字是 SQL 语句中具有特殊含义的单词，例如 SELECT，UPDATE，DELETE 等等。它们之中有的能够直接作为标识符，被称为非保留关键字（简称非保留字），但有需要经过特殊处理才能作为标识符的字，被称为保留关键字（简称保留字）。

对于保留字，必须使用反引号包裹，才能作为标识符被使用。例如：

CREATE TABLE select (a INT);

ERROR 1105 (HY000): line 0 column 19 near " (a INT)" (total length 27)

CREATE TABLE `select` (a INT);

Query OK, 0 rows affected (0.09 sec)

而非保留字则不需要反引号也能直接作为标识符。例如 BEGIN 和 END 是非保留字，以下语句能够正常执行：

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：

CREATE TABLE test.select (BEGIN int, END int);

Query OK, 0 rows affected (0.08 sec)

下表列出了 TiDB 中所有的关键字。其中保留字用 (R) 来标识。窗口函数的保留字用 (R-Window) 来标识：

A

• ACCOUNT
• ACTION
• ADD (R)
• ADMIN (R)
• ADVISE
• AFTER
• AGAINST
• AGO
• ALGORITHM
• ALL (R)
• ALTER (R)
• ALWAYS
• ANALYZE (R)
• AND (R)
• ANY
• AS (R)
• ASC (R)
• ASCII
• AUTO_ID_CACHE
• AUTO_INCREMENT
• AUTO_RANDOM
• AUTO_RANDOM_BASE
• AVG
• AVG_ROW_LENGTH

B

• BACKEND
• BACKUP
• BACKUPS
• BEGIN
• BETWEEN (R)
• BIGINT (R)
• BINARY (R)
• BINDING
• BINDINGS
• BINLOG
• BIT
• BLOB (R)
• BLOCK
• BOOL
• BOOLEAN
• BOTH (R)
• BTREE
• BUCKETS (R)
• BUILTINS (R)
• BY (R)
• BYTE

C

• CACHE
• CANCEL (R)
• CAPTURE
• CASCADE (R)
• CASCADED
• CASE (R)
• CHAIN
• CHANGE (R)
• CHAR (R)
• CHARACTER (R)
• CHARSET
• CHECK (R)
• CHECKPOINT
• CHECKSUM
• CIPHER
• CLEANUP
• CLIENT
• CMSKETCH (R)
• COALESCE
• COLLATE (R)
• COLLATION
• COLUMN (R)
• COLUMNS
• COLUMN_FORMAT
• COMMENT
• COMMIT
• COMMITTED
• COMPACT
• COMPRESSED
• COMPRESSION
• CONCURRENCY
• CONFIG
• CONNECTION
• CONSISTENT
• CONSTRAINT (R)
• CONTEXT
• CONVERT (R)
• CPU
• CREATE (R)
• CROSS (R)
• CSV_BACKSLASH_ESCAPE
• CSV_DELIMITER
• CSV_HEADER
• CSV_NOT_NULL
• CSV_NULL
• CSV_SEPARATOR
• CSV_TRIM_LAST_SEPARATORS
• CUME_DIST (R-Window)
• CURRENT
• CURRENT_DATE (R)
• CURRENT_ROLE (R)
• CURRENT_TIME (R)
• CURRENT_TIMESTAMP (R)
• CURRENT_USER (R)
• CYCLE

D

• DATA
• DATABASE (R)
• DATABASES (R)
• DATE
• DATETIME
• DAY
• DAY_HOUR (R)
• DAY_MICROSECOND (R)
• DAY_MINUTE (R)
• DAY_SECOND (R)
• DDL (R)
• DEALLOCATE
• DECIMAL (R)
• DEFAULT (R)
• DEFINER
• DELAYED (R)
• DELAY_KEY_WRITE
• DELETE (R)
• DENSE_RANK (R-Window)
• DEPTH (R)
• DESC (R)
• DESCRIBE (R)
• DIRECTORY
• DISABLE
• DISCARD
• DISK
• DISTINCT (R)
• DISTINCTROW (R)
• DIV (R)
• DO
• DOUBLE (R)
• DRAINER (R)
• DROP (R)
• DUAL (R)
• DUPLICATE
• DYNAMIC

E

• ELSE (R)
• ENABLE
• ENCLOSED (R)
• ENCRYPTION
• END
• ENFORCED
• ENGINE
• ENGINES
• ENUM
• ERROR
• ERRORS
• ESCAPE
• ESCAPED (R)
• EVENT
• EVENTS
• EVOLVE
• EXCEPT (R)
• EXCHANGE
• EXCLUSIVE
• EXECUTE
• EXISTS (R)
• EXPANSION
• EXPIRE
• EXPLAIN (R)
• EXTENDED

F

• FALSE (R)
• FAULTS
• FIELDS
• FILE
• FIRST
• FIRST_VALUE (R-Window)
• FIXED
• FLOAT (R)
• FLUSH
• FOLLOWING
• FOR (R)
• FORCE (R)
• FOREIGN (R)
• FORMAT
• FROM (R)
• FULL
• FULLTEXT (R)
• FUNCTION

G

• GENERAL
• GENERATED (R)
• GLOBAL
• GRANT (R)
• GRANTS
• GROUP (R)
• GROUPS (R-Window)

H

• HASH
• HAVING (R)
• HIGH_PRIORITY (R)
• HISTORY
• HOSTS
• HOUR
• HOUR_MICROSECOND (R)
• HOUR_MINUTE (R)
• HOUR_SECOND (R)

I

• IDENTIFIED
• IF (R)
• IGNORE (R)
• IMPORT
• IMPORTS
• IN (R)
• INCREMENT
• INCREMENTAL
• INDEX (R)
• INDEXES
• INFILE (R)
• INNER (R)
• INSERT (R)
• INSERT_METHOD
• INSTANCE
• INT (R)
• INT1 (R)
• INT2 (R)
• INT3 (R)
• INT4 (R)
• INT8 (R)
• INTEGER (R)
• INTERVAL (R)
• INTO (R)
• INVISIBLE
• INVOKER
• IO
• IPC
• IS (R)
• ISOLATION
• ISSUER

J

• JOB (R)
• JOBS (R)
• JOIN (R)
• JSON

K

• KEY (R)
• KEYS (R)
• KEY_BLOCK_SIZE
• KILL (R)

L

• LABELS
• LAG (R-Window)
• LANGUAGE
• LAST
• LASTVAL
• LAST_BACKUP
• LAST_VALUE (R-Window)
• LEAD (R-Window)
• LEADING (R)
• LEFT (R)
• LESS
• LEVEL
• LIKE (R)
• LIMIT (R)
• LINEAR (R)
• LINES (R)
• LIST
• LOAD (R)
• LOCAL
• LOCALTIME (R)
• LOCALTIMESTAMP (R)
• LOCATION
• LOCK (R)
• LOGS
• LONG (R)
• LONGBLOB (R)
• LONGTEXT (R)
• LOW_PRIORITY (R)

M

• MASTER
• MATCH (R)
• MAXVALUE (R)
• MAX_CONNECTIONS_PER_HOUR
• MAX_IDXNUM
• MAX_MINUTES
• MAX_QUERIES_PER_HOUR
• MAX_ROWS
• MAX_UPDATES_PER_HOUR
• MAX_USER_CONNECTIONS
• MB
• MEDIUMBLOB (R)
• MEDIUMINT (R)
• MEDIUMTEXT (R)
• MEMORY
• MERGE
• MICROSECOND
• MINUTE
• MINUTE_MICROSECOND (R)
• MINUTE_SECOND (R)
• MINVALUE
• MIN_ROWS
• MOD (R)
• MODE
• MODIFY
• MONTH

N

• NAMES
• NATIONAL
• NATURAL (R)
• NCHAR
• NEVER
• NEXT
• NEXTVAL
• NO
• NOCACHE
• NOCYCLE
• NODEGROUP
• NODE_ID (R)
• NODE_STATE (R)
• NOMAXVALUE
• NOMINVALUE
• NONE
• NOT (R)
• NOWAIT
• NO_WRITE_TO_BINLOG (R)
• NTH_VALUE (R-Window)
• NTILE (R-Window)
• NULL (R)
• NULLS
• NUMERIC (R)
• NVARCHAR

O

• OFFSET
• ON (R)
• ONLINE
• ONLY
• ON_DUPLICATE
• OPEN
• OPTIMISTIC (R)
• OPTIMIZE (R)
• OPTION (R)
• OPTIONALLY (R)
• OR (R)
• ORDER (R)
• OUTER (R)
• OUTFILE (R)
• OVER (R-Window)

P

• PACK_KEYS
• PAGE
• PARSER
• PARTIAL
• PARTITION (R)
• PARTITIONING
• PARTITIONS
• PASSWORD
• PERCENT_RANK (R-Window)
• PER_DB
• PER_TABLE
• PESSIMISTIC (R)
• PLUGINS
• PRECEDING
• PRECISION (R)
• PREPARE
• PRE_SPLIT_REGIONS
• PRIMARY (R)
• PRIVILEGES
• PROCEDURE (R)
• PROCESS
• PROCESSLIST
• PROFILE
• PROFILES
• PUMP (R)

Q

• QUARTER
• QUERIES
• QUERY
• QUICK

R

• RANGE (R)
• RANK (R-Window)
• RATE_LIMIT
• READ (R)
• REAL (R)
• REBUILD
• RECOVER
• REDUNDANT
• REFERENCES (R)
• REGEXP (R)
• REGION (R)
• REGIONS (R)
• RELEASE (R)
• RELOAD
• REMOVE
• RENAME (R)
• REORGANIZE
• REPAIR
• REPEAT (R)
• REPEATABLE
• REPLACE (R)
• REPLICA
• REPLICATION
• REQUIRE (R)
• RESPECT
• RESTORE
• RESTORES
• RESTRICT (R)
• REVERSE
• REVOKE (R)
• RIGHT (R)
• RLIKE (R)
• ROLE
• ROLLBACK
• ROUTINE
• ROW (R)
• ROWS (R-Window)
• ROW_COUNT
• ROW_FORMAT
• ROW_NUMBER (R-Window)
• RTREE

S

• SAMPLES (R)
• SECOND
• SECONDARY_ENGINE
• SECONDARY_LOAD
• SECONDARY_UNLOAD
• SECOND_MICROSECOND (R)
• SECURITY
• SELECT (R)
• SEND_CREDENTIALS_TO_TIKV
• SEPARATOR
• SEQUENCE
• SERIAL
• SERIALIZABLE
• SESSION
• SET (R)
• SETVAL
• SHARD_ROW_ID_BITS
• SHARE
• SHARED
• SHOW (R)
• SHUTDOWN
• SIGNED
• SIMPLE
• SKIP_SCHEMA_FILES
• SLAVE
• SLOW
• SMALLINT (R)
• SNAPSHOT
• SOME
• SOURCE
• SPATIAL (R)
• SPLIT (R)
• SQL (R)
• SQL_BIG_RESULT (R)
• SQL_BUFFER_RESULT
• SQL_CACHE
• SQL_CALC_FOUND_ROWS (R)
• SQL_NO_CACHE
• SQL_SMALL_RESULT (R)
• SQL_TSI_DAY
• SQL_TSI_HOUR
• SQL_TSI_MINUTE
• SQL_TSI_MONTH
• SQL_TSI_QUARTER
• SQL_TSI_SECOND
• SQL_TSI_WEEK
• SQL_TSI_YEAR
• SSL (R)
• START
• STARTING (R)
• STATS (R)
• STATS_AUTO_RECALC
• STATS_BUCKETS (R)
• STATS_HEALTHY (R)
• STATS_HISTOGRAMS (R)
• STATS_META (R)
• STATS_PERSISTENT
• STATS_SAMPLE_PAGES
• STATUS
• STORAGE
• STORED (R)
• STRAIGHT_JOIN (R)
• STRICT_FORMAT
• SUBJECT
• SUBPARTITION
• SUBPARTITIONS
• SUPER
• SWAPS
• SWITCHES
• SYSTEM_TIME

T

• TABLE (R)
• TABLES
• TABLESPACE
• TABLE_CHECKSUM
• TEMPORARY
• TEMPTABLE
• TERMINATED (R)
• TEXT
• THAN
• THEN (R)
• TIDB (R)
• TIFLASH (R)
• TIKV_IMPORTER
• TIME
• TIMESTAMP
• TINYBLOB (R)
• TINYINT (R)
• TINYTEXT (R)
• TO (R)
• TOPN (R)
• TRACE
• TRADITIONAL
• TRAILING (R)
• TRANSACTION
• TRIGGER (R)
• TRIGGERS
• TRUE (R)
• TRUNCATE
• TYPE

U

• UNBOUNDED
• UNCOMMITTED
• UNDEFINED
• UNICODE
• UNION (R)
• UNIQUE (R)
• UNKNOWN
• UNLOCK (R)
• UNSIGNED (R)
• UPDATE (R)
• USAGE (R)
• USE (R)
• USER
• USING (R)
• UTC_DATE (R)
• UTC_TIME (R)
• UTC_TIMESTAMP (R)

V

• VALIDATION
• VALUE
• VALUES (R)
• VARBINARY (R)
• VARCHAR (R)
• VARCHARACTER (R)
• VARIABLES
• VARYING (R)
• VIEW
• VIRTUAL (R)
• VISIBLE

W

• WARNINGS
• WEEK
• WEIGHT_STRING
• WHEN (R)
• WHERE (R)
• WIDTH (R)
• WINDOW (R-Window)
• WITH (R)
• WITHOUT
• WRITE (R)

X

• X509
• XOR (R)

Y

• YEAR
• YEAR_MONTH (R)

Z

• ZEROFILL (R)