9.3. Reserved Words

Certain words such as SELECT, DELETE, or BIGINT are reserved and require special treatment for use as identifiers such as table and column names. This may also be true for the names of built-in functions.

Reserved words are permitted as identifiers if you quote them as described in Section 9.2, "Schema Object Names":

mysql> CREATE TABLE interval (begin INT, end
        INT);ERROR 1064 (42000): You have an error in your SQL syntax ...near 'interval (begin INT, end INT)'mysql> CREATE TABLE `interval` (begin INT, end INT);Query OK, 0 rows affected (0.01 sec)

Exception: A word that follows a period in a qualified name must be an identifier, so it need not be quoted even if it is reserved:

mysql> CREATE TABLE mydb.interval (begin INT, end
        INT);Query OK, 0 rows affected (0.01 sec)

Names of built-in functions are permitted as identifiers but may require care to be used as such. For example, COUNT is acceptable as a column name. However, by default, no whitespace is permitted in function invocations between the function name and the following "(" character. This requirement enables the parser to distinguish whether the name is used in a function call or in nonfunction context. For further detail on recognition of function names, see Section 9.2.4, "Function Name Parsing and Resolution".

The words in the following table are explicitly reserved in MySQL 5.7. In addition, _FILENAME is reserved. At some point, you might upgrade to a higher version, so it is a good idea to have a look at future reserved words, too. You can find these in the manuals that cover higher versions of MySQL. Most of the words in the table are forbidden by standard SQL as column or table names (for example, GROUP). A few are reserved because MySQL needs them and uses a yacc parser. A reserved word can be used as an identifier if you quote it.

For a more detailed list of reserved words, including differences between versions, see Reserved Words in MySQL 5.7.

Table 9.2. Reserved Words in MySQL 5.7.2

ACCESSIBLE ADD ALL
ALTER ANALYZE AND
AS ASC ASENSITIVE
BEFORE BETWEEN BIGINT
BINARY BLOB BOTH
BY CALL CASCADE
CASE CHANGE CHAR
CHARACTER CHECK COLLATE
COLUMN CONDITION CONSTRAINT
CONTINUE CONVERT CREATE
CROSS CURRENT_DATE CURRENT_TIME
CURRENT_TIMESTAMP CURRENT_USER CURSOR
DATABASE DATABASES DAY_HOUR
DAY_MICROSECOND DAY_MINUTE DAY_SECOND
DEC DECIMAL DECLARE
DEFAULT DELAYED DELETE
DESC DESCRIBE DETERMINISTIC
DISTINCT DISTINCTROW DIV
DOUBLE DROP DUAL
EACH ELSE ELSEIF
ENCLOSED ESCAPED EXISTS
EXIT EXPLAIN FALSE
FETCH FLOAT FLOAT4
FLOAT8 FOR FORCE
FOREIGN FROM FULLTEXT
GET GRANT GROUP
HAVING HIGH_PRIORITY HOUR_MICROSECOND
HOUR_MINUTE HOUR_SECOND IF
IGNORE IN INDEX
INFILE INNER INOUT
INSENSITIVE INSERT INT
INT1 INT2 INT3
INT4 INT8 INTEGER
INTERVAL INTO IO_AFTER_GTIDS
IO_BEFORE_GTIDS IS ITERATE
JOIN KEY KEYS
KILL LEADING LEAVE
LEFT LIKE LIMIT
LINEAR LINES LOAD
LOCALTIME LOCALTIMESTAMP LOCK
LONG LONGBLOB LONGTEXT
LOOP LOW_PRIORITY MASTER_BIND
MASTER_SSL_VERIFY_SERVER_CERT MATCH MAXVALUE
MEDIUMBLOB MEDIUMINT MEDIUMTEXT
MIDDLEINT MINUTE_MICROSECOND MINUTE_SECOND
MOD MODIFIES NATURAL
NONBLOCKING NOT NO_WRITE_TO_BINLOG
NULL NUMERIC ON
OPTIMIZE OPTION OPTIONALLY
OR ORDER OUT
OUTER OUTFILE PARTITION
PRECISION PRIMARY PROCEDURE
PURGE RANGE READ
READS READ_WRITE REAL
REFERENCES REGEXP RELEASE
RENAME REPEAT REPLACE
REQUIRE RESIGNAL RESTRICT
RETURN REVOKE RIGHT
RLIKE SCHEMA SCHEMAS
SECOND_MICROSECOND SELECT SENSITIVE
SEPARATOR SET SHOW
SIGNAL SMALLINT SPATIAL
SPECIFIC SQL SQLEXCEPTION
SQLSTATE SQLWARNING SQL_BIG_RESULT
SQL_CALC_FOUND_ROWS SQL_SMALL_RESULT SSL
STARTING STRAIGHT_JOIN TABLE
TERMINATED THEN TINYBLOB
TINYINT TINYTEXT TO
TRAILING TRIGGER TRUE
UNDO UNION UNIQUE
UNLOCK UNSIGNED UPDATE
USAGE USE USING
UTC_DATE UTC_TIME UTC_TIMESTAMP
VALUES VARBINARY VARCHAR
VARCHARACTER VARYING WHEN
WHERE WHILE WITH
WRITE XOR YEAR_MONTH
ZEROFILL

Table 9.3. New Reserved Words in MySQL 5.7

NONBLOCKING

MySQL permits some keywords to be used as unquoted identifiers because many people previously used them. Examples are those in the following list:




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