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。