详细解释mysql全文索引之停止词(stopword)

innodb和myisam分别有两组不同的设置，控制着对应的stopword。

全文检索时，停止词列表将会被读取和检索，在不同的字符集和排序方式下（character_set_server and collation_server 系统变量），可能会导致在搜索时的停止词的不匹配。

停止词是否大小写敏感，取决于不同的排序方式，比如：latin1_swedish_ci下停止词是大小写敏感的，latin1_general_cs 或 latin1_bin下停止词是大小写不敏感的。

innodb的索引停止词

innodb的默认停止词列表很短。查询INFORMATION_SCHEMA.INNODB_FT_DEFAULT_STOPWORD表来查看默认的innodb停止词表。

mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_FT_DEFAULT_STOPWORD;
+-------+
| value |
+-------+
| a     |
| about |
| an    |
| are   |
| as    |
| at    |
| be    |
| by    |
| com   |
| de    |
| en    |
| for   |
| from  |
| how   |
| i     |
| in    |
| is    |
| it    |
| la    |
| of    |
| on    |
| or    |
| that  |
| the   |
| this  |
| to    |
| was   |
| what  |
| when  |
| where |
| who   |
| will  |
| with  |
| und   |
| the   |
| www   |
+-------+
36 rows in set (0.00 sec)

myisam索引的停止词

myisam索引的停止词列表与innodb不同，默认的myisam停止词列表是直接在mysql程序源码中已写入。设置ft_stopword_file系统变量来指定停止词文件，从而覆盖默认设置。

在mysql源程序的 storage/myisam/ft_static.c file文件中，你可以找到默认的myisam停止词列表：

a's able about above according
accordingly across actually after afterwards
again against ain't all allow
allows almost alone along already
also although always am among
amongst an and another any
anybody anyhow anyone anything anyway
anyways anywhere apart appear appreciate
appropriate are aren't around as
aside ask asking associated at
available away awfully be became
because become becomes becoming been
before beforehand behind being believe
below beside besides best better
between beyond both brief but
by c'mon c's came can
can't cannot cant cause causes
certain certainly changes clearly co
com come comes concerning consequently
consider considering contain containing contains
corresponding could couldn't course currently
definitely described despite did didn't
different do does doesn't doing
don't done down downwards during
each edu eg eight either
else elsewhere enough entirely especially
et etc even ever every
everybody everyone everything everywhere ex
exactly example except far few
fifth first five followed following
follows for former formerly forth
four from further furthermore get
gets getting given gives go
goes going gone got gotten
greetings had hadn't happens hardly
has hasn't have haven't having
he he's hello help hence
her here here's hereafter hereby
herein hereupon hers herself hi
him himself his hither hopefully
how howbeit however i'd i'll
i'm i've ie if ignored
immediate in inasmuch inc indeed
indicate indicated indicates inner insofar
instead into inward is isn't
it it'd it'll it's its
itself just keep keeps kept
know known knows last lately
later latter latterly least less
lest let let's like liked
likely little look looking looks
ltd mainly many may maybe
me mean meanwhile merely might
more moreover most mostly much
must my myself name namely
nd near nearly necessary need
needs neither never nevertheless new
next nine no nobody non
none noone nor normally not
nothing novel now nowhere obviously
of off often oh ok
okay old on once one
ones only onto or other
others otherwise ought our ours
ourselves out outside over overall
own particular particularly per perhaps
placed please plus possible presumably
probably provides que quite qv
rather rd re really reasonably
regarding regardless regards relatively respectively
right said same saw say
saying says second secondly see
seeing seem seemed seeming seems
seen self selves sensible sent
serious seriously seven several shall
she should shouldn't since six
so some somebody somehow someone
something sometime sometimes somewhat somewhere
soon sorry specified specify specifying
still sub such sup sure
t's take taken tell tends
th than thank thanks thanx
that that's thats the their
theirs them themselves then thence
there there's thereafter thereby therefore
therein theres thereupon these they
they'd they'll they're they've think
third this thorough thoroughly those
though three through throughout thru
thus to together too took
toward towards tried tries truly
try trying twice two un
under unfortunately unless unlikely until
unto up upon us use
used useful uses using usually
value various very via viz
vs want wants was wasn't
way we we'd we'll we're
we've welcome well went were
weren't what what's whatever when
whence whenever where where's whereafter
whereas whereby wherein whereupon wherever
whether which while whither who
who's whoever whole whom whose
why will willing wish with
within without won't wonder would
wouldn't yes yet you you'd
you'll you're you've your yours
yourself yourselves zero