PHP及MySQL保留关键字列表整理如下:
1、PHP保留字
以下是 PHP 中预定义标识符的列表。没有列在下面的标识符可以在脚本中作为自定义标识符使用。这些列表包括关键字和预定义变量、常量和类名。这些列表可能有遗漏,它是不完整的。
关键词列表
这些词语在 PHP 中有着特殊的意义。它们中有些像是函数,有些像是常量……但是它们不是的,它们只是语言结构的一部分。不能使用它们的任何一个作为常量、方法名或是类名。但是可以将它们作为变量名使用,不过这样会导致混淆。
表 L.1. PHP 关键词
and | or | xor | __FILE__ | exception (PHP 5) |
__LINE__ | array() | as | break | case |
class | const | continue | declare | default |
die() | do | echo() | else | elseif |
empty() | enddeclare | endfor | endforeach | endif |
endswitch | endwhile | eval() | exit() | extends |
for | foreach | function | global | if |
include() | include_once() | isset() | list() | new |
print() | require() | require_once() | return() | static |
switch | unset() | use | var | while |
__FUNCTION__ | __CLASS__ | __METHOD__ | final (as of PHP 5) | php_user_filter (as of PHP 5) |
interface (as of PHP 5) | implements (as of PHP 5) | extends | public (as of PHP 5) | private (as of PHP 5) |
protected (as of PHP 5) | abstract (as of PHP 5) | clone (as of PHP 5) | try (as of PHP 5) | catch (as of PHP 5) |
throw (as of PHP 5) | cfunction (PHP 4 only) | old_function (PHP 4 only) | this (as of PHP 5) | namespace (PHP 6 only) |
import (PHP 6 only) | goto (PHP 6 only) | |
|
尝试使用一个识别符,例如使用嵌入式MySQL数据类型或函数名作为表名或列名,例如TIMESTAMP或GROUP,会造成一个常见问题。允许你这样操作(例如,ABS可以作为一个列名)。但是,默认情况下,在数调用中在函数名和后面的‘(’字符之间不允许有空格。该要求使函数调用与列名引用不同。
该行为的不利结果是在某些上下文中省略一个空格会使识别符解释为函数名。例如,该语句合法:
mysql> CREATE TABLE abs (val INT);但省略abs后面的空格会造成语法错误,因为省略后该语句好像要调用ABS()函数:
mysql> CREATE TABLE abs(val INT);如果SQL服务器模式包括IGNORE_SPACE模式值,服务器允许函数调用时在函数名和后面的 ‘(’字符之间有空格。这样使函数名被视为保留字。结果是,与函数名相同的识别符必须按照9.2节,“数据库、表、索引、列和别名”中所描述的引起来。SQL服务器模式按照5.3.2节,“SQL服务器模式”中所描述的进行控制。
限定名中句点后面的字必须为一个识别符,因此不需要将它引起来,即使它是一个保留字。
在MySQL中,下表中的字显式被保留。其中大多数字进制被标准SQL用作列名和/或表名(例如,GROUP)。少数被保留了,因为MySQL需要它们, (目前)使用yacc解析程序。保留字被引起来后可以用作识别符:
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 | CONNECTION | 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 |
GOTO | 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 | IS |
ITERATE | JOIN | KEY |
KEYS | KILL | LABEL |
LEADING | LEAVE | LEFT |
LIKE | LIMIT | LINEAR |
LINES | LOAD | LOCALTIME |
LOCALTIMESTAMP | LOCK | LONG |
LONGBLOB | LONGTEXT | LOOP |
LOW_PRIORITY | MATCH | MEDIUMBLOB |
MEDIUMINT | MEDIUMTEXT | MIDDLEINT |
MINUTE_MICROSECOND | MINUTE_SECOND | MOD |
MODIFIES | NATURAL | NOT |
NO_WRITE_TO_BINLOG | NULL | NUMERIC |
ON | OPTIMIZE | OPTION |
OPTIONALLY | OR | ORDER |
OUT | OUTER | OUTFILE |
PRECISION | PRIMARY | PROCEDURE |
PURGE | RAID0 | RANGE |
READ | READS | REAL |
REFERENCES | REGEXP | RELEASE |
RENAME | REPEAT | REPLACE |
REQUIRE | RESTRICT | RETURN |
REVOKE | RIGHT | RLIKE |
SCHEMA | SCHEMAS | SECOND_MICROSECOND |
SELECT | SENSITIVE | SEPARATOR |
SET | SHOW | 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 | X509 |
XOR | YEAR_MONTH | ZEROFILL |
MySQL 允许部分关键字用做未引起来的识别符,因为许多人以前曾使用过它们。下面列出了一些例子:
-
ACTION
-
BIT
-
DATE
-
ENUM
-
NO
-
TEXT
-
TIME
-
TIMESTAMP
PS:记住啊,建库,建表的时候,如果用到这些关键字了。一写要用反引号 '` '给其包上啊。就是ESC下面的那个带波浪线的键子 。
评论