Weka链接Mysql数据库

Weka简介

　　Weka的全名是怀卡托智能分析环境（Waikato Environment for Knowledge Analysis），是一款免费的，非商业化（与之对应的是SPSS公司商业数据挖掘产品--Clementine ）的，基于JAVA环境下开源的机器学习（machine learning）以及数据挖掘（data minining）软件。

Weka数据格式

WEKA存储数据的格式是ARFF（Attribute-Relation File Format）文件，这是一种ASCII文本文件。二维表格存储在如下的ARFF文件中。这也就是WEKA自带的“weather.arff” 文件，在WEKA安装目录的“data”子目录下可以找到。

代码:

% ARFF file for the weather data with some numric features

@relation weather

@attribute outlook {sunny, overcast, rainy}

@attribute temperature real

@attribute humidity real

@attribute windy {TRUE, FALSE}

@attribute play {yes, no}

@data

% 14 instances

sunny,85,85,FALSE,no

sunny,80,90,TRUE,no

overcast,83,86,FALSE,yes

rainy,70,96,FALSE,yes

rainy,68,80,FALSE,yes

rainy,65,70,TRUE,no

overcast,64,65,TRUE,yes

sunny,72,95,FALSE,no

sunny,69,70,FALSE,yes

rainy,75,80,FALSE,yes

sunny,75,70,TRUE,yes

overcast,72,90,TRUE,yes

overcast,81,75,FALSE,yes

rainy,71,91,TRUE,no

Mysql简介

　　MySQL是一个关系型数据库管理系统，由瑞典MySQL AB公司开发，目前属于Oracle公司。MySQL是一种关联数据库管理系统，关联数据库将数据保存在不同的表中，而不是将所有数据放在一个大仓库内，这样就增加了速度并提高了灵活性。MySQL所使用的SQL语言是用于访问数据库的最常用标准化语言。MySQL软件采用了双授权政策（本词条“授权政策”），它分为社区版和商业版，由于其体积小、速度快、总体拥有成本低，尤其是开放源码这一特点，一般中小型网站的开发都选择MySQL作为网站数据库。由于其社区版的性能卓越，搭配PHP和Apache可组成良好的开发环境。

Weka直接连接Mysql

由于Weka数据格式的特殊性，如果想在Weka中处理数据，必须首先将数据的格式转化成ARFF格式，所以需要经历SQL->ARFF的转化，比较麻烦，但是Weka已经为此做了充分的准备，只需简单配置就可在Weka GUI上直接连接操作Mysql数据库。

准备工作：

Java运行环境

Weka安装

mysql-connector-java-5.1.26-bin.jar

详细配置步骤：

　　在weka的安装目录下新建lib文件夹，将mysql-connector-java-5.1.26-bin.jar包复制到此lib文件夹下，并且在%JAVA_HOME%\jre\lib\ext"下也复制一份mysql-connector-java-5.1.6-bin.jar。

　　在weka的安装目录下找到weka.jar,将其解压到当前目录，你会看到多出来一个名为weka的文件夹，进到此文件夹目录下，找到experiment文件夹下的DatabaseUtils.props.mysql，将其改名为DatabaseUtils.props，替换原有的DatabaseUtils.props文件，并将其修改文件里的以下内容：

 # Database settings for MySQL 3.23.x, 4.x

 #

 # General information on database access can be found here:

 # http://weka.wikispaces.com/Databases

 #

 # url:     http://www.mysql.com/

 # jdbc:    http://www.mysql.com/products/connector/j/

 # author:  Fracpete (fracpete at waikato dot ac dot nz)

 # version: $Revision: 5836 $

 # JDBC driver (comma-separated list)

 #jdbcDriver=org.gjt.mm.mysql.Driver

 jdbcDriver=com.mysql.jdbc.Driver

 # database URL

 #jdbcURL=jdbc:mysql://server_name:3306/database_name

 jdbcURL=jdbc:mysql://localhost:3306/rtest

 # specific data types

 # string, getString() = 0;    --> nominal

 # boolean, getBoolean() = 1;  --> nominal

 # double, getDouble() = 2;    --> numeric

 # byte, getByte() = 3;        --> numeric

 # short, getByte()= 4;        --> numeric

 # int, getInteger() = 5;      --> numeric

 # long, getLong() = 6;        --> numeric

 # float, getFloat() = 7;      --> numeric

 # date, getDate() = 8;        --> date

 # text, getString() = 9;      --> string

 # time, getTime() = 10;       --> date

 # specific data types

  string, getString() = 0;    --> nominal

  boolean, getBoolean() = 1;  --> nominal

  double, getDouble() = 2;    --> numeric

  byte, getByte() = 3;        --> numeric

  short, getByte()= 4;        --> numeric

  int, getInteger() = 5;      --> numeric

  long, getLong() = 6;        --> numeric

  float, getFloat() = 7;      --> numeric

  date, getDate() = 8;        --> date

  text, getString() = 9;      --> string

  time, getTime() = 10;       --> date

 TINYINT=3

 SMALLINT=4

 #SHORT=4

 SHORT=5

 INTEGER=5

 INT=5

 INT_UNSIGNED=6

 BIGINT=6

 LONG=6

 REAL=7

 NUMERIC=2

 DECIMAL=2

 FLOAT=2

 DOUBLE=2

 CHAR=0

 TEXT=0

 VARCHAR=0

 LONGVARCHAR=9

 BINARY=0

 VARBINARY=0

 LONGVARBINARY=9

 BIT=1

 BLOB=9

 DATE=8

 TIME=8

 DATETIME=8

 TIMESTAMP=8

 # other options

 CREATE_DOUBLE=DOUBLE

 CREATE_STRING=TEXT

 CREATE_INT=INT

 CREATE_DATE=DATETIME

 DateFormat=yyyy-MM-dd HH:mm:ss

 checkUpperCaseNames=false

 checkLowerCaseNames=false

 checkForTable=true

 # All the reserved keywords for this database

 # Based on the keywords listed at the following URL (2009-04-13):

 # http://dev.mysql.com/doc/mysqld-version-reference/en/mysqld-version-reference-reservedwords-5-0.html

 Keywords=\

   ADD,\

   ALL,\

   ALTER,\

   ANALYZE,\

   AND,\

   AS,\

   ASC,\

   ASENSITIVE,\

   BEFORE,\

   BETWEEN,\

   BIGINT,\

   BINARY,\

   BLOB,\

   BOTH,\

   BY,\

   CALL,\

   CASCADE,\

   CASE,\

   CHANGE,\

   CHAR,\

   CHARACTER,\

   CHECK,\

   COLLATE,\

   COLUMN,\

   COLUMNS,\

   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,\

   FIELDS,\

   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,\

   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,\

   PRIVILEGES,\

   PROCEDURE,\

   PURGE,\

   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,\

   SONAME,\

   SPATIAL,\

   SPECIFIC,\

   SQL,\

   SQLEXCEPTION,\

   SQLSTATE,\

   SQLWARNING,\

   SQL_BIG_RESULT,\

   SQL_CALC_FOUND_ROWS,\

   SQL_SMALL_RESULT,\

   SSL,\

   STARTING,\

   STRAIGHT_JOIN,\

   TABLE,\

   TABLES,\

   TERMINATED,\

   THEN,\

   TINYBLOB,\

   TINYINT,\

   TINYTEXT,\

   TO,\

   TRAILING,\

   TRIGGER,\

   TRUE,\

   UNDO,\

   UNION,\

   UNIQUE,\

   UNLOCK,\

   UNSIGNED,\

   UPDATE,\

   UPGRADE,\

   USAGE,\

   USE,\

   USING,\

   UTC_DATE,\

   UTC_TIME,\

   UTC_TIMESTAMP,\

   VALUES,\

   VARBINARY,\

   VARCHAR,\

   VARCHARACTER,\

   VARYING,\

   WHEN,\

   WHERE,\

   WHILE,\

   WITH,\

   WRITE,\

   XOR,\

   YEAR_MONTH,\

   ZEROFILL

 # The character to append to attribute names to avoid exceptions due to

 # clashes between keywords and attribute names

 KeywordsMaskChar=_

 #flags for loading and saving instances using DatabaseLoader/Saver

 nominalToStringLimit=50

 idColumn=auto_generated_id

　　然后将weka文件夹打包成weka.jar，替换原来的weka.jar。运行weka，选择open DB，选择user，输入用户名和密码，点击connect，info显示connecting to:jdbc:mysql://localhost:3306/myweka = true，代表连接成功。Explorer就从数据库中载入数据集了。