• Keywords and Reserved Words

    Keywords and Reserved Words

    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：

    1. mysql> CREATE TABLE select (a INT);
    2. ERROR 1105 (HY000): line 0 column 19 near " (a INT)" (total length 27)
    3. mysql> CREATE TABLE `select` (a INT);
    4. 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：

    1. mysql> CREATE TABLE `select` (BEGIN int, END int);
    2. 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：

    1. mysql> CREATE TABLE test.select (BEGIN int, END int);
    2. 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 (R) 来标识：

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