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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, “Database, Table, Index, Column, and Alias 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 allowed 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 non-function context. For further detail on recognition of function names, see Section 9.2.3, “Function Name Parsing and Resolution”.

The words in the following table are explicitly reserved in MySQL 5.0. At some point, you might upgrade to a higher version, so it's 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.

ADDALLALTER
ANALYZEANDAS
ASCASENSITIVEBEFORE
BETWEENBIGINTBINARY
BLOBBOTHBY
CALLCASCADECASE
CHANGECHARCHARACTER
CHECKCOLLATECOLUMN
CONDITIONCONSTRAINTCONTINUE
CONVERTCREATECROSS
CURRENT_DATECURRENT_TIMECURRENT_TIMESTAMP
CURRENT_USERCURSORDATABASE
DATABASESDAY_HOURDAY_MICROSECOND
DAY_MINUTEDAY_SECONDDEC
DECIMALDECLAREDEFAULT
DELAYEDDELETEDESC
DESCRIBEDETERMINISTICDISTINCT
DISTINCTROWDIVDOUBLE
DROPDUALEACH
ELSEELSEIFENCLOSED
ESCAPEDEXISTSEXIT
EXPLAINFALSEFETCH
FLOATFLOAT4FLOAT8
FORFORCEFOREIGN
FROMFULLTEXTGRANT
GROUPHAVINGHIGH_PRIORITY
HOUR_MICROSECONDHOUR_MINUTEHOUR_SECOND
IFIGNOREIN
INDEXINFILEINNER
INOUTINSENSITIVEINSERT
INTINT1INT2
INT3INT4INT8
INTEGERINTERVALINTO
ISITERATEJOIN
KEYKEYSKILL
LEADINGLEAVELEFT
LIKELIMITLINES
LOADLOCALTIMELOCALTIMESTAMP
LOCKLONGLONGBLOB
LONGTEXTLOOPLOW_PRIORITY
MATCHMEDIUMBLOBMEDIUMINT
MEDIUMTEXTMIDDLEINTMINUTE_MICROSECOND
MINUTE_SECONDMODMODIFIES
NATURALNOTNO_WRITE_TO_BINLOG
NULLNUMERICON
OPTIMIZEOPTIONOPTIONALLY
ORORDEROUT
OUTEROUTFILEPRECISION
PRIMARYPROCEDUREPURGE
RAID0READREADS
REALREFERENCESREGEXP
RELEASERENAMEREPEAT
REPLACEREQUIRERESTRICT
RETURNREVOKERIGHT
RLIKESCHEMASCHEMAS
SECOND_MICROSECONDSELECTSENSITIVE
SEPARATORSETSHOW
SMALLINTSONAMESPATIAL
SPECIFICSQLSQLEXCEPTION
SQLSTATESQLWARNINGSQL_BIG_RESULT
SQL_CALC_FOUND_ROWSSQL_SMALL_RESULTSSL
STARTINGSTRAIGHT_JOINTABLE
TERMINATEDTHENTINYBLOB
TINYINTTINYTEXTTO
TRAILINGTRIGGERTRUE
UNDOUNIONUNIQUE
UNLOCKUNSIGNEDUPDATE
USAGEUSEUSING
UTC_DATEUTC_TIMEUTC_TIMESTAMP
VALUESVARBINARYVARCHAR
VARCHARACTERVARYINGWHEN
WHEREWHILEWITH
WRITEX509XOR
YEAR_MONTHZEROFILL 

The following are new reserved words in MySQL 5.0:

ASENSITIVECALLCONDITION
CONTINUECURSORDECLARE
DETERMINISTICEACHELSEIF
EXITFETCHINOUT
INSENSITIVEITERATELEAVE
LOOPMODIFIESOUT
READSRELEASEREPEAT
RETURNSCHEMASCHEMAS
SENSITIVESPECIFICSQL
SQLEXCEPTIONSQLSTATESQLWARNING
TRIGGERUNDOWHILE

MySQL allows 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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