R连接Oracle、MySQL、SQLServer

1、下载mysql-connector-odbc，并安装

2、windows：控制面板->管理工具->数据源(ODBC)

->ODBC数据管理器->系统DSN->添加->MySQL ODBC Driver

->data source name（如：mysql_data）  

description  

TCP/IP Server（服务器IP）  

port（如：3306）  

user  

password  

database  

test（显示连接成功）  

->在“系统数据源”中显示“名称”，“驱动程序”

3、在R界面

3.1、程序包->安装程序包->RODBC

3.2、library(RODBC)

3.3、查看可用的数据源

>  odbcDataSources()
                                             dBASE Files                                              Excel Files
   "Microsoft Access dBASE Driver (*.dbf, *.ndx, *.mdx)" "Microsoft Excel Driver (*.xls, *.xlsx, *.xlsm, *.xlsb)"
                                      MS Access Database                                                    MySQL
              "Microsoft Access Driver (*.mdb, *.accdb)"                             "MySQL ODBC 5.3 ANSI Driver"
                                              mysql_data
                            "MySQL ODBC 5.3 ANSI Driver"

3.4、data_table <- odbcConnect("mysql_data", uid="root", pwd="123")

> data_table
RODBC Connection 1
Details:
  case=tolower
  DSN=mysql_data
  UID=root
  PWD=******

3.5、  查看数据库中的表

> sqlTables(data_table)    

TABLE_CAT TABLE_SCHEM      TABLE_NAME    TABLE_TYPE    REMARKS

1     sakila                                  actor         TABLE       

2     sakila                             actor_info       VIEW                 VIEW

3     sakila                                address       TABLE       

4     sakila                               category       TABLE       

5     sakila                                   city          TABLE       

6     sakila                                country       TABLE       

7     sakila                               customer      TABLE   

3.6、查看表的内容，存到数据框里

> data_country<-sqlFetch(data_table,"country") 

> data_country    

             country_id                  country         last_update

1            7                               Armenia       2006-02-15 04:44:00

2            8                               Australia       2006-02-15 04:44:00

3            9                               Austria         2006-02-15 04:44:00

4            23                             China           2006-02-15 04:44:00

3.7、SQL查询

> sql_country<-sqlQuery(data_table,"select country_id,country,last_update from country where country_id<5 order by country")
> sql_country
          country_id          country                      last_update
1          1                     Afghanistan                2006-02-15 04:44:00
2          2                     Algeria                       2006-02-15 04:44:00
3          3                     American Samoa         2006-02-15 04:44:00
4          4                     Angola                       2006-02-15 04:44:00

3.8、

head函数获取前n条记录

 > head(data_country,n=5)
  country_id        country         last_update
1          1    Afghanistan 2006-02-15 04:44:00
2          2        Algeria 2006-02-15 04:44:00
3          3 American Samoa 2006-02-15 04:44:00
4          4         Angola 2006-02-15 04:44:00
5          5       Anguilla 2006-02-15 04:44:00

head函数获取后n条记录
> tail(data_country,n=4)
    country_id              country         last_update
106        106 Virgin Islands, U.S. 2006-02-15 04:44:00
107        107                Yemen 2006-02-15 04:44:00
108        108           Yugoslavia 2006-02-15 04:44:00
109        109               Zambia 2006-02-15 04:44:00

3.9、关闭R与数据库的连接

> odbcClose(data_table)

R连接Oracle、MySQL、SQLServer

原文：http://www.cnblogs.com/wwxbi/p/4338506.html