Like MySQL, MaxDB has a number of reserved words that have special meanings. Normally, they cannot be used as names of identifiers, such as database or table names. The following table lists reserved words in MaxDB, indicates the context in which those words are used, and indicates whether or not they have counterparts in MySQL. If such a counterpart exists, the meaning in MySQL might be identical or differing in some aspects. The main purpose is to list in which respects MaxDB differs from MySQL; therefore, this list is not complete.
Para la lista de palabras reservardas en MySQL, Visite Sección 9.6, “Tratamiento de palabras reservadas en MySQL”.
Reserved in MaxDB | Context of usage in MaxDB | MySQL counterpart |
@ |
Can prefix identifier, like “@table” | Not allowed |
ADDDATE() |
Funcion SQL |
ADDDATE() ; nuevo en MySQL 4.1.1 |
ADDTIME() |
Funcion SQL |
ADDTIME() ; nuevo en MySQL 4.1.1 |
ALPHA |
Funcion SQL | Sin comparacion |
ARRAY |
Tipo de Dato | Sin Implementar |
ASCII() |
Funcion SQL |
ASCII() , implementado pero con otro significado |
AUTOCOMMIT |
Transactions; ON by default |
Transactions; OFF by default |
BOOLEAN |
Column types; BOOLEAN accepts as values only
TRUE , FALSE , and
NULL
|
BOOLEAN was added in MySQL 4.1.0; it is a synonym for
BOOL which is mapped to
TINYINT(1) . It accepts integer values
in the same range as TINYINT as well as
NULL . TRUE and
FALSE can be used as aliases for
1 and 0 . |
CHECK |
CHECK TABLE |
CHECK TABLE ; similar, but not identical usage |
COLUMN |
Column types |
COLUMN ; noise word |
CHAR() |
SQL function |
CHAR() ; identical syntax; similar, not identical
usage |
COMMIT |
Implicit commits of transactions happen when data definition statements are issued | Implicit commits of transactions happen when data definition statements are issued, and also with a number of other statements |
COSH() |
SQL function | Nothing comparable |
COT() |
SQL function |
COT() ; identical syntax and implementation |
CREATE |
SQL, data definition language | CREATE |
DATABASE |
SQL function |
DATABASE() ; DATABASE is used in a
different context; for example, CREATE
DATABASE
|
DATE() |
SQL function | CURRENT_DATE |
DATEDIFF() |
SQL function |
DATEDIFF() ; new in MySQL 4.1.1 |
DAY() |
SQL function | Nothing comparable |
DAYOFWEEK() |
SQL function |
DAYOFWEEK() ; by default, 1
represents Monday in MaxDB and Sunday in MySQL |
DISTINCT |
SQL functions AVG , MAX ,
MIN , SUM
|
DISTINCT ; but used in a different context:
SELECT DISTINCT
|
DROP |
DROP INDEX , for example |
DROP INDEX ; similar, but not identical usage |
EBCDIC() |
SQL function | Nothing comparable |
EXPAND() |
SQL function | Nothing comparable |
EXPLAIN |
Optimization |
EXPLAIN ; similar, but not identical usage |
FIXED() |
SQL function | Nothing comparable |
FLOAT() |
SQL function | Nothing comparable |
HEX() |
SQL function |
HEX() ; similar, but not identical usage |
INDEX() |
SQL function |
INSTR() or LOCATE() ; similar, but
not identical syntaxes and meanings |
INDEX |
USE INDEX , IGNORE INDEX and
similar hints are used right after
SELECT ; for example, SELECT
... USE INDEX
|
USE INDEX , IGNORE INDEX and
similar hints are used in the FROM
clause of a SELECT query; for example,
in SELECT ... FROM ... USE INDEX
|
INITCAP() |
SQL function | Nothing comparable |
LENGTH() |
SQL function |
LENGTH() ; identical syntax, but slightly different
implementation |
LFILL() |
SQL function | Nothing comparable |
LIKE |
Comparisons |
LIKE ; but the extended LIKE MaxDB
provides rather resembles the MySQL
REGEX
|
LIKE wildcards |
MaxDB supports “%”, “_”,
“Control-underline”, “Control-up
arrow”, “*”, and “?” as
wildcards in LIKE comparisons |
MySQL supports “%”, and “_” as wildcards in
LIKE comparisons |
LPAD() |
SQL function |
LPAD() ; slightly different implementation |
LTRIM() |
SQL function |
LTRIM() ; slightly different implementation |
MAKEDATE() |
SQL function |
MAKEDATE() ; new in MySQL 4.1.1 |
MAKETIME() |
SQL function |
MAKETIME() ; new in MySQL 4.1.1 |
MAPCHAR() |
SQL function | Nothing comparable |
MICROSECOND() |
SQL function |
MICROSECOND() ; new in MySQL 4.1.1 |
NOROUND() |
SQL function | Nothing comparable |
NULL |
Column types; comparisons |
NULL ; MaxDB supports special NULL
values that are returned by arithmetic operations that
lead to an overflow or a division by zero; MySQL does not
support such special values |
PI |
SQL function |
PI() ; identical syntax and implementation, but
parentheses are mandatory in MySQL |
REF |
Data type | Nothing comparable |
RFILL() |
SQL function | Nothing comparable |
ROWNO |
Predicate in WHERE clause |
Similar to LIMIT clause |
RPAD() |
SQL function |
RPAD() ; slightly different implementation |
RTRIM() |
SQL function |
RTRIM() ; slightly different implementation |
SEQUENCE |
CREATE SEQUENCE , DROP SEQUENCE
|
AUTO_INCREMENT ; similar concept, but different
implementation |
SINH() |
SQL function | Nothing comparable |
SOUNDS() |
SQL function |
SOUNDEX() ; slightly different syntax |
STATISTICS |
UPDATE STATISTICS |
ANALYZE TABLE ; similar concept, but different
implementation |
SUBSTR() |
SQL function |
SUBSTRING() ; slightly different implementation |
SUBTIME() |
SQL function |
SUBTIME() ; new in MySQL 4.1.1 |
SYNONYM |
Data definition language: CREATE [PUBLIC] SYNONYM ,
RENAME SYNONYM , DROP
SYNONYM
|
Nothing comparable |
TANH() |
SQL function | Nothing comparable |
TIME() |
SQL function | CURRENT_TIME |
TIMEDIFF() |
SQL function |
TIMEDIFF() ; new in MySQL 4.1.1 |
TIMESTAMP() |
SQL function |
TIMESTAMP() ; new in MySQL 4.1.1 |
TIMESTAMP() as argument to
DAYOFMONTH() and
DAYOFYEAR()
|
SQL function | Nothing comparable |
TIMEZONE() |
SQL function | Nothing comparable |
TRANSACTION() |
Returns the ID of the current transaction | Nothing comparable |
TRANSLATE() |
SQL function |
REPLACE() ; identical syntax and implementation |
TRIM() |
SQL function |
TRIM() ; slightly different implementation |
TRUNC() |
SQL function |
TRUNCATE() ; slightly different syntax and
implementation |
USE |
Switches to a new database instance; terminates the connection to the current database instance; all subsequent commands are referred to this database instance |
USE ; identical syntax, but does not terminate the
connection to the current database |
USER |
SQL function |
USER() ; identical syntax, but slightly different
implementation, and parentheses are mandatory in MySQL |
UTC_DIFF() |
SQL function |
UTC_DATE() ; provides a means to calculate the same
result as UTC_DIFF()
|
VALUE() |
SQL function, alias for COALESCE()
|
COALESCE() ; identical syntax and implementation |
VARIANCE() |
SQL function |
VARIANCE() ; new in MySQL 4.1.0 |
WEEKOFYEAR() |
SQL function |
WEEKOFYEAR() ; new in MySQL 4.1.1 |
Ésta es una traducción del manual de referencia de MySQL, que puede encontrarse en dev.mysql.com. El manual de referencia original de MySQL está escrito en inglés, y esta traducción no necesariamente está tan actualizada como la versión original. Para cualquier sugerencia sobre la traducción y para señalar errores de cualquier tipo, no dude en dirigirse a mysql-es@vespito.com.