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)