RMySQL数据库编程指南
R语言作为统计学一门语言，一直在小众领域闪耀着光芒。直到大数据的爆发，R语言变成了一门炙手可热的数据分析的利器。随着越来越多的工程背景的人的加入，R语言的社区在迅速扩大成长。现在已不仅仅是统计领域，教育，银行，电商，互联网….都在使用R语言。
要成为有理想的极客，我们不能停留在语法上，要掌握牢固的数学，概率，统计知识，同时还要有创新精神，把R语言发挥到各个领域。让我们一起动起来吧，开始R的极客理想。
转载请注明出处：
http://blog.fens.me/r-mysql-rmysql/
前言
MySQL是一款最常用到开源数据库软件，安装简单，运行稳定，非常适用于中小型的数据存储。R作为数据分析的工具，当然要支持数据库驱动接口。让R和MySQL配合在一起，所能爆发出的能量是巨大的。
由于操作系统的原因，让Win和Linux有不一样的字符集，不一样的运行时环境。所以，今天我们讲一下如何在Linux和Win上面安装和使用RMySQL。
目录
- RMySQL介绍
- RMySQL在Linux下安装
- RMySQL在Win7下安装
- RMySQL函数使用
- RMySQL案例实践
1. RMySQL介绍
RMySQL一个R语言程序包，提供了访问MySQL数据库的R语言接口程序，RMySQL需求依赖于DBI项目。RMySQL不仅提供了基本的数据库访问，SQL查询，还封装了一些方法。比较读整表，分页，data.frame快速插入等等的功能。掌握好RMySQL，数据库编辑将得心应手！！
2. RMySQL在Linux下安装
Linux系统环境：
- Linux: Ubuntu 12.04.2 LTS 64bit server
- Linux字符集: en_US.UTF-8
- R: 3.0.1, x86_64-pc-linux-gnu (64-bit)
- MySQL: Ver 14.14 Distrib 5.5.29 64bit server
- MySQL字符集: utf8
~ uname -a
Linux conan 3.5.0-23-generic #35~precise1-Ubuntu SMP Fri Jan 25 17:13:26 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
~ cat /etc/issue
Ubuntu 12.04.2 LTS \n \l
~ locale
LANG=en_US.UTF-8
LANGUAGE=
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=en_US.UTF-8
~ R --version
R version 3.0.1 (2013-05-16) -- "Good Sport"
Copyright (C) 2013 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under the terms of the
GNU General Public License versions 2 or 3.
For more information about these matters see
http://www.gnu.org/licenses/.
~ mysql --version
mysql Ver 14.14 Distrib 5.5.29, for debian-linux-gnu (x86_64) using readline 6.2
mysql> show variables like '%char%';
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)
在R环境中安装RMySQL
~ R
> install.packages('RMySQL')
also installing the dependency ‘DBI’
trying URL 'http://cran.dataguru.cn/src/contrib/DBI_0.2-7.tar.gz'
Content type 'application/x-gzip' length 194699 bytes (190 Kb)
opened URL
==================================================
downloaded 190 Kb
trying URL 'http://cran.dataguru.cn/src/contrib/RMySQL_0.9-3.tar.gz'
Content type 'application/x-gzip' length 165363 bytes (161 Kb)
opened URL
==================================================
downloaded 161 Kb
...
Configuration error:
could not find the MySQL installation include and/or library
directories. Manually specify the location of the MySQL
libraries and the header files and re-run R CMD INSTALL.
INSTRUCTIONS:
1. Define and export the 2 shell variables PKG_CPPFLAGS and
PKG_LIBS to include the directory for header files (*.h)
and libraries, for example (using Bourne shell syntax):
export PKG_CPPFLAGS="-I"
export PKG_LIBS="-L -lmysqlclient"
Re-run the R INSTALL command:
R CMD INSTALL RMySQL_.tar.gz
2. Alternatively, you may pass the configure arguments
--with-mysql-dir= (distribution directory)
or
--with-mysql-inc= (where MySQL header files reside)
--with-mysql-lib= (where MySQL libraries reside)
in the call to R INSTALL --configure-args='...'
R CMD INSTALL --configure-args='--with-mysql-dir=DIR' RMySQL_.tar.gz
ERROR: configuration failed for package ‘RMySQL’
* removing ‘/home/conan/R/x86_64-pc-linux-gnu-library/3.0/RMySQL’
The downloaded source packages are in
‘/tmp/Rtmpu0Gn88/downloaded_packages’
Warning message:
In install.packages("RMySQL") :
installation of package ‘RMySQL’ had non-zero exit status
安装出错了，提示我们需要增加MySQL安装目录的配置参数
# 安装mysql类库
~ sudo apt-get install libdbd-mysql libmysqlclient-dev
# 找到mysql的安装目录
~ whereis mysql
mysql: /usr/bin/mysql /etc/mysql /usr/lib/mysql /usr/bin/X11/mysql /usr/share/mysql /usr/share/man/man1/mysql.1.gz
# 找到刚刚下载的RMySQL_.tar.gz
~ ls /tmp/Rtmpu0Gn88/downloaded_packages
DBI_0.2-7.tar.gz RMySQL_0.9-3.tar.gz
# 通过命令安装RMySQL
~ R CMD INSTALL --configure-args='--with-mysql-dir=/usr/lib/mysql' /tmp/Rtmpu0Gn88/downloaded_packages/RMySQL_0.9-3.tar.gz
* installing to library ‘/home/conan/R/x86_64-pc-linux-gnu-library/3.0’
* installing *source* package ‘RMySQL’ ...
** package ‘RMySQL’ successfully unpacked and MD5 sums checked
checking for gcc... gcc
checking for C compiler default output file name... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables...
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ANSI C... none needed
checking how to run the C preprocessor... gcc -E
checking for compress in -lz... yes
checking for getopt_long in -lc... yes
checking for mysql_init in -lmysqlclient... yes
checking for egrep... grep -E
checking for ANSI C header files... yes
checking for sys/types.h... yes
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking mysql.h usability... no
checking mysql.h presence... no
checking for mysql.h... no
checking /usr/local/include/mysql/mysql.h usability... no
checking /usr/local/include/mysql/mysql.h presence... no
checking for /usr/local/include/mysql/mysql.h... no
checking /usr/include/mysql/mysql.h usability... yes
checking /usr/include/mysql/mysql.h presence... yes
checking for /usr/include/mysql/mysql.h... yes
configure: creating ./config.status
config.status: creating src/Makevars
** libs
gcc -std=gnu99 -I/usr/share/R/include -DNDEBUG -I/usr/include/mysql -fpic -O3 -pipe -g -c RS-DBI.c -o RS-DBI.o
gcc -std=gnu99 -I/usr/share/R/include -DNDEBUG -I/usr/include/mysql -fpic -O3 -pipe -g -c RS-MySQL.c -o RS-MySQL.o
gcc -std=gnu99 -shared -o RMySQL.so RS-DBI.o RS-MySQL.o -lmysqlclient -lz -L/usr/lib/R/lib -lR
installing to /home/conan/R/x86_64-pc-linux-gnu-library/3.0/RMySQL/libs
** R
** inst
** preparing package for lazy loading
Creating a generic function for ‘format’ from package ‘base’ in package ‘RMySQL’
Creating a generic function for ‘print’ from package ‘base’ in package ‘RMySQL’
** help
*** installing help indices
** building package indices
** installing vignettes
** testing if installed package can be loaded
* DONE (RMySQL)
RMySQL安装成功.
在MySQL中建库建表
~ mysql -uroot -p
mysql> create database rmysql;
Query OK, 1 row affected (0.00 sec)
mysql> grant all on rmysql.* to rmysql@'%' identified by 'rmysql';
Query OK, 0 rows affected (0.00 sec)
mysql> grant all on rmysql.* to rmysql@localhost identified by 'rmysql';
Query OK, 0 rows affected (0.00 sec)
mysql> use rmysql
Database changed
mysql> CREATE TABLE t_user(
-> id INT PRIMARY KEY AUTO_INCREMENT,
-> user varchar(12) NOT NULL UNIQUE
-> )ENGINE=INNODB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.07 sec)
mysql> INSERT INTO t_user(user) values('A1'),('AB'),('fens.me');
Query OK, 3 rows affected (0.04 sec)
Records: 3 Duplicates: 0 Warnings: 0
mysql> SELECT * FROM t_user;
+----+---------+
| id | user |
+----+---------+
| 1 | A1 |
| 2 | AB |
| 3 | fens.me |
+----+---------+
3 rows in set (0.00 sec)
通过R程序，读MySQL数据库数据
~ R
> library(RMySQL)
Loading required package: DBI
> conn <- dbConnect(MySQL(), dbname = "rmysql", username="rmysql", password="rmysql")
> users = dbGetQuery(conn, "SELECT * FROM t_user")
> dbDisconnect(conn)
[1] TRUE
> users
id user
1 1 A1
2 2 AB
3 3 fens.me
好了，我们实现了在Linux下R和MySQL的连接。
3. RMySQL在Win7下安装
Win系统环境：
- Win7: 64位 旗舰版
- Win字符集: gbk,utf8
- R: 3.0.1, x86_64-w64-mingw32/x64 (64-bit)
- MySQL: mysql Ver 14.14 Distrib 5.6.11, for Win64 (x86_64)
~ R --version
R version 3.0.1 (2013-05-16) -- "Good Sport"
Copyright (C) 2013 The R Foundation for Statistical Computing
Platform: x86_64-w64-mingw32/x64 (64-bit)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under the terms of the
GNU General Public License versions 2 or 3.
For more information about these matters see
http://www.gnu.org/licenses/.
~ mysql --version
mysql Ver 14.14 Distrib 5.6.11, for Win64 (x86_64)
mysql> show variables like '%char%';
+--------------------------+------------------------------------+
| Variable_name | Value |
+--------------------------+------------------------------------+
| character_set_client | gbk |
| character_set_connection | gbk |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | gbk |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | D:\toolkit\mysql56\share\charsets\ |
+--------------------------+------------------------------------+
8 rows in set (0.07 sec)
在R环境中安装RMySQL
~ D:\workspace\R\mysql>R
> install.packages('RMySQl')
package 'RMySQl' is not available (for R version 3.0.1)
我们看到提示，没有对应的RMySQL安装版本。
# 下载RMySQL源代码包
> install.packages("RMySQL", type="source")
URLhttp://cran.dataguru.cn/src/contrib/RMySQL_0.9-3.tar.gz'
Content type 'application/x-gzip' length 165363 bytes (161 Kb)
URL
downloaded 161 Kb
* installing *source* package 'RMySQL' ...
** 'RMySQL'MD5
checking for $MYSQL_HOME... not found... searching registry...
cygwin warning:
MS-DOS style path detected: C:/PROGRA~1/R/R-30~1.1/bin/x64/Rscript
Preferred POSIX equivalent is: /cygdrive/c/PROGRA~1/R/R-30~1.1/bin/x64/Rscript
CYGWIN environment variable option "nodosfilewarning" turns off this warning.
Consult the user's guide for more details about POSIX paths:
http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
readRegistry("SOFTWARE\\MySQL AB", hive = "HLM", maxdepth = 2) :
Registry key 'SOFTWARE\MySQL AB' not found
ERROR: configuration failed for package 'RMySQL'
* removing 'C:/Program Files/R/R-3.0.1/library/RMySQL'
'C:\Users\Administrator\AppData\Local\Temp\RtmpsfqQjK\downloaded_packages'
In install.packages("RMySQL", type = "source") :
'RMySQL'B0
找到源代码包：RMySQL_0.9-3.tar.gz
~ dir C:\Users\Administrator\AppData\Local\Temp\RtmpsfqQjK\downloaded_packages
2013-09-24 13:16 165,363 RMySQL_0.9-3.tar.gz
通过源代码包安装
~ D:\workspace\R\mysql>R CMD INSTALL C:\Users\Administrator\AppData\Local\Temp\RtmpsfqQjK\downloaded_packages\RMySQL_0.9-3
.tar.gz
* installing to library 'C:/Program Files/R/R-3.0.1/library'
* installing *source* package 'RMySQL' ...
** 'RMySQL'MD5
checking for $MYSQL_HOME... not found... searching registry...
cygwin warning:
MS-DOS style path detected: C:/PROGRA~1/R/R-30~1.1/bin/x64/Rscript
Preferred POSIX equivalent is: /cygdrive/c/PROGRA~1/R/R-30~1.1/bin/x64/Rscript
CYGWIN environment variable option "nodosfilewarning" turns off this warning.
Consult the user's guide for more details about POSIX paths:
http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
readRegistry("SOFTWARE\\MySQL AB", hive = "HLM", maxdepth = 2) :
Registry key 'SOFTWARE\MySQL AB' not found
ERROR: configuration failed for package 'RMySQL'
* removing 'C:/Program Files/R/R-3.0.1/library/RMySQL'
设置MYSQL_HOME的环境变量
set MYSQL_HOME=D:\toolkit\mysql56
注： MYSQL_HOME建议设置在系统环境变量中。
再一次安装RMySQL
D:\workspace\R\mysql>R CMD INSTALL C:\Users\Administrator\AppData\Local\Temp\RtmpsfqQjK\downloaded_packages\RMySQL_0.9-3
.tar.gz
* installing to library 'C:/Program Files/R/R-3.0.1/library'
* installing *source* package 'RMySQL' ...
** 'RMySQL'MD5
checking for $MYSQL_HOME... D:\toolkit\mysql56
cygwin warning:
MS-DOS style path detected: D:\toolkit\mysql56
Preferred POSIX equivalent is: /cygdrive/d/toolkit/mysql56
CYGWIN environment variable option "nodosfilewarning" turns off this warning.
Consult the user's guide for more details about POSIX paths:
http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
** libs
: this package has a non-empty 'configure.win' file,
so building only the main architecture
cygwin warning:
MS-DOS style path detected: C:/PROGRA~1/R/R-30~1.1/etc/x64/Makeconf
Preferred POSIX equivalent is: /cygdrive/c/PROGRA~1/R/R-30~1.1/etc/x64/Makeconf
CYGWIN environment variable option "nodosfilewarning" turns off this warning.
Consult the user's guide for more details about POSIX paths:
http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
gcc -m64 -I"C:/PROGRA~1/R/R-30~1.1/include" -DNDEBUG -I"D:\toolkit\mysql56"/include -I"d:/RCompile/CRANpkg/extralibs6
4/local/include" -O2 -Wall -std=gnu99 -mtune=core2 -c RS-DBI.c -o RS-DBI.o
RS-DBI.c: In function 'RS_na_set':
RS-DBI.c:1219:11: warning: variable 'c' set but not used [-Wunused-but-set-variable]
gcc -m64 -I"C:/PROGRA~1/R/R-30~1.1/include" -DNDEBUG -I"D:\toolkit\mysql56"/include -I"d:/RCompile/CRANpkg/extralibs6
4/local/include" -O2 -Wall -std=gnu99 -mtune=core2 -c RS-MySQL.c -o RS-MySQL.o
RS-MySQL.c: In function 'RS_MySQL_fetch':
RS-MySQL.c:657:13: warning: variable 'fld_nullOk' set but not used [-Wunused-but-set-variable]
RS-MySQL.c: In function 'RS_DBI_invokeBeginGroup':
RS-MySQL.c:1137:30: warning: variable 'val' set but not used [-Wunused-but-set-variable]
RS-MySQL.c: In function 'RS_DBI_invokeNewRecord':
RS-MySQL.c:1158:20: warning: variable 'val' set but not used [-Wunused-but-set-variable]
RS-MySQL.c: In function 'RS_MySQL_dbApply':
RS-MySQL.c:1219:38: warning: variable 'fld_nullOk' set but not used [-Wunused-but-set-variable]
gcc -m64 -shared -s -static-libgcc -o RMySQL.dll tmp.def RS-DBI.o RS-MySQL.o D:\toolkit\mysql56/bin/libmySQL.dll -Ld:/RC
ompile/CRANpkg/extralibs64/local/lib/x64 -Ld:/RCompile/CRANpkg/extralibs64/local/lib -LC:/PROGRA~1/R/R-30~1.1/bin/x64 -l
R
gcc.exe: error: D:\toolkit\mysql56/bin/libmySQL.dll: No such file or directory
ERROR: compilation failed for package 'RMySQL'
* removing 'C:/Program Files/R/R-3.0.1/library/RMySQL'
错误为没有找到动态链接库：D:\toolkit\mysql56/bin/libmySQL.dll
# 复制动态链接库libmySQL.dll
cp D:\toolkit\mysql56\lib\libmysql.dll D:\toolkit\mysql56\bin\
mv D:\toolkit\mysql56\bin\libmysql.dll D:\toolkit\mysql56\bin\libmySQL.dll
再一次安装RMySQL
~ D:\workspace\R\mysql>R CMD INSTALL C:\Users\Administrator\AppData\Local\Temp\RtmpsfqQjK\downloaded_packages\RMySQL_0.9-3
.tar.gz
* installing to library 'C:/Program Files/R/R-3.0.1/library'
* installing *source* package 'RMySQL' ...
** 'RMySQL'MD5
checking for $MYSQL_HOME... D:\toolkit\mysql56
cygwin warning:
MS-DOS style path detected: D:\toolkit\mysql56
Preferred POSIX equivalent is: /cygdrive/d/toolkit/mysql56
CYGWIN environment variable option "nodosfilewarning" turns off this warning.
Consult the user's guide for more details about POSIX paths:
http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
** libs
: this package has a non-empty 'configure.win' file,
so building only the main architecture
cygwin warning:
MS-DOS style path detected: C:/PROGRA~1/R/R-30~1.1/etc/x64/Makeconf
Preferred POSIX equivalent is: /cygdrive/c/PROGRA~1/R/R-30~1.1/etc/x64/Makeconf
CYGWIN environment variable option "nodosfilewarning" turns off this warning.
Consult the user's guide for more details about POSIX paths:
http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
gcc -m64 -I"C:/PROGRA~1/R/R-30~1.1/include" -DNDEBUG -I"D:\toolkit\mysql56"/include -I"d:/RCompile/CRANpkg/extralibs6
4/local/include" -O2 -Wall -std=gnu99 -mtune=core2 -c RS-DBI.c -o RS-DBI.o
RS-DBI.c: In function 'RS_na_set':
RS-DBI.c:1219:11: warning: variable 'c' set but not used [-Wunused-but-set-variable]
gcc -m64 -I"C:/PROGRA~1/R/R-30~1.1/include" -DNDEBUG -I"D:\toolkit\mysql56"/include -I"d:/RCompile/CRANpkg/extralibs6
4/local/include" -O2 -Wall -std=gnu99 -mtune=core2 -c RS-MySQL.c -o RS-MySQL.o
RS-MySQL.c: In function 'RS_MySQL_fetch':
RS-MySQL.c:657:13: warning: variable 'fld_nullOk' set but not used [-Wunused-but-set-variable]
RS-MySQL.c: In function 'RS_DBI_invokeBeginGroup':
RS-MySQL.c:1137:30: warning: variable 'val' set but not used [-Wunused-but-set-variable]
RS-MySQL.c: In function 'RS_DBI_invokeNewRecord':
RS-MySQL.c:1158:20: warning: variable 'val' set but not used [-Wunused-but-set-variable]
RS-MySQL.c: In function 'RS_MySQL_dbApply':
RS-MySQL.c:1219:38: warning: variable 'fld_nullOk' set but not used [-Wunused-but-set-variable]
gcc -m64 -shared -s -static-libgcc -o RMySQL.dll tmp.def RS-DBI.o RS-MySQL.o D:\toolkit\mysql56/bin/libmySQL.dll -Ld:/RC
ompile/CRANpkg/extralibs64/local/lib/x64 -Ld:/RCompile/CRANpkg/extralibs64/local/lib -LC:/PROGRA~1/R/R-30~1.1/bin/x64 -l
R
installing to C:/Program Files/R/R-3.0.1/library/RMySQL/libs/x64
** R
** inst
** preparing package for lazy loading
Creating a generic function for 'format' from package 'base' in package 'RMySQL'
Creating a generic function for 'print' from package 'base' in package 'RMySQL'
** help
*** installing help indices
** building package indices
** installing vignettes
** testing if installed package can be loaded
MYSQL_HOME defined as D:\toolkit\mysql56
* DONE (RMySQL)
安装成功！
在MySQL中建库建表
~ mysql -uroot -p
mysql> create database rmysql;
Query OK, 1 row affected (0.04 sec)
mysql> grant all on rmysql.* to rmysql@'%' identified by 'rmysql';
Query OK, 0 rows affected (0.00 sec)
mysql> grant all on rmysql.* to rmysql@localhost identified by 'rmysql';
Query OK, 0 rows affected (0.00 sec)
mysql> use rmysql
Database changed
mysql> CREATE TABLE t_user(
-> id INT PRIMARY KEY AUTO_INCREMENT,
-> user varchar(12) NOT NULL UNIQUE
-> )ENGINE=INNODB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (1.01 sec)
mysql>
mysql> INSERT INTO t_user(user) values('A1'),('AB'),('fens.me');
Query OK, 3 rows affected (0.05 sec)
Records: 3 Duplicates: 0 Warnings: 0
mysql> SELECT * FROM t_user;
+----+---------+
| id | user |
+----+---------+
| 1 | A1 |
| 2 | AB |
| 3 | fens.me |
+----+---------+
3 rows in set (0.03 sec)
通过R程序，读MySQL数据库数据。
注：如果刚才没有把MYSQL_HOME的变量写到环境变更中，每次在启动R之前要，先设置变量。
~ set MYSQL_HOME=D:\toolkit\mysql56
~ R
> library(RMySQL)
DBI
MYSQL_HOME defined as D:\toolkit\mysql56
> conn <- dbConnect(MySQL(), dbname = "rmysql", username="root", password="",client.flag=CLIENT_MULTI_STATEMENTS)
> users = dbGetQuery(conn, "SELECT * FROM t_user")
> dbDisconnect(conn)
[1] TRUE
> users
id user
1 1 A1
2 2 AB
3 3 fens.me
好了，我们实现了在Win7下R和MySQL的连接。
4. RMySQL函数使用
环境都安装好了，接下来我们具体使用一下RMySQL的包。
- RMySQL辅助操作
- RMySQL数据库操作
- 针对win的字符集设置
1). RMySQL辅助操作
加载类库
> library(RMySQL)建立本地连接
> conn <- dbConnect(MySQL(), dbname = "rmysql", username="rmysql", password="rmysql",client.flag=CLIENT_MULTI_STATEMENTS)
建立远程连接
> conn <- dbConnect(MySQL(), dbname = "rmysql", username="rmysql", password="rmysql",host="192.168.1.201",port=3306)
关闭连接
dbDisconnect(conn)查看数据库的表
> dbListTables(conn)
[1] "t_user"
查看表的字段
> dbListFields(conn, "t_user")
[1] "id" "user"
查询MySQL信息
> summary(MySQL(), verbose = TRUE)
<MySQLDriver:(23864)>
Driver name: MySQL
Max connections: 16
Conn. processed: 3
Default records per fetch: 500
DBI API version:
# MySQL连接实例信息
> summary(conn, verbose = TRUE)
<MySQLConnection:(23864,2)>
User: root
Host: localhost
Dbname: rmysql
Connection type: localhost via TCP/IP
MySQL server version: 5.6.11
MySQL client version: 5.6.11
MySQL protocol version: 10
MySQL server thread id: 35
No resultSet available
# MySQL连接信息
> dbListConnections(MySQL())
[[1]]
<MySQLConnection:(23864,2)>
2). RMySQL数据库操作
RMySQL数据库操作
# 建表并插入数据
> t_demo<-data.frame(
a=seq(1:10),
b=letters[1:10],
c=rnorm(10)
)
> dbWriteTable(conn, "t_demo", t_demo)
# 获得整个表数据
> dbReadTable(conn, "t_demo")
a b c
1 1 a 0.98868164
2 2 b -0.66935770
3 3 c 0.27703638
4 4 d 1.36137156
5 5 e -0.70291017
6 6 f 1.61235088
7 7 g 0.17616068
8 8 h 0.29700017
9 9 i 0.19032719
10 10 j -0.06222173
# 插入新数据
> dbWriteTable(conn, "t_demo", t_demo, append=TRUE)
> dbReadTable(conn, "t_demo")
row_names a b c
1 1 1 a 0.98868164
2 2 2 b -0.66935770
3 3 3 c 0.27703638
4 4 4 d 1.36137156
5 5 5 e -0.70291017
6 6 6 f 1.61235088
7 7 7 g 0.17616068
8 8 8 h 0.29700017
9 9 9 i 0.19032719
10 10 10 j -0.06222173
11 1 1 a 0.98868164
12 2 2 b -0.66935770
13 3 3 c 0.27703638
14 4 4 d 1.36137156
15 5 5 e -0.70291017
16 6 6 f 1.61235088
17 7 7 g 0.17616068
18 8 8 h 0.29700017
19 9 9 i 0.19032719
20 10 10 j -0.06222173
# 覆盖原表数据
> dbWriteTable(conn, "t_demo", t_demo, overwrite=TRUE)
# 1). 查询数据
> d0 <- dbGetQuery(conn, "SELECT * FROM t_demo where c>0")
> class(d0)
[1] "data.frame"
> d0
row_names a b c
1 1 1 a 0.9886816
2 3 3 c 0.2770364
3 4 4 d 1.3613716
4 6 6 f 1.6123509
5 7 7 g 0.1761607
6 8 8 h 0.2970002
7 9 9 i 0.1903272
# 2). 执行SQL脚本查询，并分页
> rs <- dbSendQuery(conn, "SELECT * FROM t_demo where c>0")
> class(rs)
[1] "MySQLResult"
attr(,"package")
[1] "RMySQL"
> mysqlCloseResult(rs)
[1] TRUE
> d1 <- fetch(rs, n = 3)
> d1
row_names a b c
1 1 1 a 0.9886816
2 3 3 c 0.2770364
3 4 4 d 1.3613716
# 3). 查看集统计信息
> summary(rs, verbose = TRUE)
row_names a b c
Length:7 Min. :1.000 Length:7 Min. :0.1762
Class :character 1st Qu.:3.500 Class :character 1st Qu.:0.2337
Mode :character Median :6.000 Mode :character Median :0.2970
Mean :5.429 Mean :0.7004
3rd Qu.:7.500 3rd Qu.:1.1750
Max. :9.000 Max. :1.6124
# 不插入row.names字段
> dbWriteTable(conn, "t_demo", t_demo,row.names=FALSE,overwrite=TRUE)
> dbGetQuery(conn, "SELECT * FROM t_demo where c>0")
a b c
1 1 a 0.9886816
2 3 c 0.2770364
3 4 d 1.3613716
4 6 f 1.6123509
5 7 g 0.1761607
6 8 h 0.2970002
7 9 i 0.1903272
# 删除表
> if(dbExistsTable(conn,'t_demo')){
+ dbRemoveTable(conn, "t_demo")
+ }
[1] TRUE
执行SQL语句，dbSendQuery
> query<-dbSendQuery(conn, "show tables")
> data <- fetch(query, n = -1)
> data
Tables_in_rmysql
1 t_demo
2 t_user
> mysqlCloseResult(query)
[1] TRUE
4). win的字符集设置
在win7中，向MySQL插入中文
mysql> INSERT INTO t_user(user) values('小朋友'),('你好'),('正确了');
Query OK, 3 rows affected (0.07 sec)
Records: 3 Duplicates: 0 Warnings: 0
mysql> select * from t_user;
+----+---------+
| id | user |
+----+---------+
| 1 | A1 |
| 2 | AB |
| 3 | fens.me |
| 5 | 你好 |
| 4 | 小朋友 |
| 6 | 正确了 |
+----+---------+
6 rows in set (0.07 sec)
通过RMySQL查询
> dbGetQuery(conn, "SELECT * FROM t_user")
id user
1 1 A1
2 2 AB
3 3 fens.me
4 5 ??
5 4 ???
6 6 ???
设置GKB字符集
> dbDisconnect(conn)
> conn <- dbConnect(MySQL(), dbname = "rmysql", username="root", password="",client.flag=CLIENT_MULTI_STATEMENTS)
> dbSendQuery(conn,'SET NAMES gbk')
<mysqlresult:(23864,43,2)>
> query<-dbSendQuery(conn, "SELECT * FROM t_user")
> data <- fetch(query, n = -1)
> mysqlCloseResult(query)
[1] TRUE
> data
id user
1 1 A1
2 2 AB
3 3 fens.me
4 5 你好
5 4 小朋友
6 6 正确了
OK，我们在win下面修正字符编号的问题。
5. RMySQL案例实践
系统需求描述：Linux MySQL，Win7的R环境，远程连接
- 1. 通过SQL新建表t_blog，主键索引，唯一键索引
- 2. 用RMySQL插入数据，包括中文字段
- 3. 再用RMySQL取出数据
1). 通过SQL新建表t_blog，主键索引，唯一键索引
建表语句
CREATE TABLE t_blog(
id INT PRIMARY KEY AUTO_INCREMENT,
title varchar(12) NOT NULL UNIQUE,
author varchar(12) NOT NULL,
length int NOT NULL,
create_date timestamp NOT NULL DEFAULT now()
)ENGINE=INNODB DEFAULT CHARSET=UTF8;
mysql> desc t_blog;
+-------------+-------------+------+-----+-------------------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+-------------+------+-----+-------------------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| title | varchar(12) | NO | UNI | NULL | |
| author | varchar(12) | NO | | NULL | |
| length | int(11) | NO | | NULL | |
| create_date | timestamp | NO | | CURRENT_TIMESTAMP | |
+-------------+-------------+------+-----+-------------------+----------------+
5 rows in set (0.00 sec)
mysql> show indexes from t_blog;
+--------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+--------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| t_blog | 0 | PRIMARY | 1 | id | A | 3 | NULL | NULL | | BTREE | | |
| t_blog | 0 | title | 1 | title | A | 3 | NULL | NULL | | BTREE | | |
+--------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
2 rows in set (0.00 sec)
INSERT INTO t_blog(title,author,length) values('你好，第一篇','Conan',20),('RMySQL数据库编程','Conan',99),('R的极客理想系列文章','Conan',15);
mysql> select * from t_blog;
+----+------------------------------+--------+--------+---------------------+
| id | title | author | length | create_date |
+----+------------------------------+--------+--------+---------------------+
| 1 | 你好，第一篇 | Conan | 20 | 2013-08-15 00:13:13 |
| 2 | RMySQL数据库编程 | Conan | 99 | 2013-08-15 00:13:13 |
| 3 | R的极客理想系列文章 | Conan | 15 | 2013-08-15 00:13:13 |
+----+------------------------------+--------+--------+---------------------+
3 rows in set (0.00 sec)
2). 用RMySQL插入数据，包括中文字段，再取出数据
> library(RMySQL)
> conn <- dbConnect(MySQL(), dbname = "rmysql", username="rmysql", password="rmysql",host="192.168.1.201",port=3306)
>
> dbSendQuery(conn,'SET NAMES gbk')
<mysqlresult:(23864,49,0)>
> dbSendQuery(conn,"INSERT INTO t_blog(title,author,length) values('R插入的新文章','Conan',50)");
<mysqlresult:(23864,49,1)>
>
> query<-dbSendQuery(conn, "SELECT * FROM t_blog")
Warning message:
In mysqlExecStatement(conn, statement, ...) :
RS-DBI driver warning: (unrecognized MySQL field type 7 in column 4 imported as character)
> data <- fetch(query, n = -1)
> mysqlCloseResult(query)
[1] TRUE
> print(data)
id title author length create_date
1 1 你好，第一篇 Conan 20 2013-08-15 00:13:13
2 2 RMySQL数据库编程 Conan 99 2013-08-15 00:13:13
3 3 R的极客理想系列文章 Conan 15 2013-08-15 00:13:13
4 4 R插入的新文章 Conan 50 2013-08-15 00:29:45
>
> dbDisconnect(conn)
[1] TRUE
特别提示，不能用dbWriteTable函数！
RMySQL数据库编程指南的更多相关文章
- 转】RMySQL数据库编程指南
原博文出自于: http://blog.fens.me/category/%E6%95%B0%E6%8D%AE%E5%BA%93/page/2/ 感谢! Posted: Sep 24, 2013 Ta ...
- (转载)JDOM/XPATH编程指南
JDOM/XPATH编程指南 本文分别介绍了 JDOM 和 XPATH,以及结合两者进行 XML 编程带来的好处. 前言 XML是一种优秀的数据打包和数据交换的形式,在当今XML大行于天下,如果没有听 ...
- Spark结构式流编程指南
Spark结构式流编程指南 概览 Structured Streaming 是一个可拓展,容错的,基于Spark SQL执行引擎的流处理引擎.使用小量的静态数据模拟流处理.伴随流数据的到来,Spark ...
- Apache Spark 2.2.0 中文文档 - Spark Streaming 编程指南 | ApacheCN
Spark Streaming 编程指南 概述 一个入门示例 基础概念 依赖 初始化 StreamingContext Discretized Streams (DStreams)(离散化流) Inp ...
- Structured Streaming Programming Guide结构化流编程指南
目录 Overview Quick Example Programming Model Basic Concepts Handling Event-time and Late Data Fault T ...
- Spark(1.6.1) Sql 编程指南+实战案例分析
首先看看从官网学习后总结的一个思维导图 概述(Overview) Spark SQL是Spark的一个模块,用于结构化数据处理.它提供了一个编程的抽象被称为DataFrames,也可以作为分布式SQL ...
- SparkR(R on Spark)编程指南 含 dataframe操作 2.0
SparkR(R on Spark)编程指南 Spark 2015-06-09 28155 1评论 下载为PDF 为什么不允许复制 关注iteblog_hadoop公众号,并在这里评论区留言 ...
- SparkR(R on Spark)编程指南 含 dataframe操作
SparkR(R on Spark)编程指南 Spark 2015-06-09 28155 1评论 下载为PDF 为什么不允许复制 关注iteblog_hadoop公众号,并在这里评论区留言 ...
- [转]ODBC编程指南
DM4 ODBC编程指南本章结合DM4数据库的特点,比较全面系统的介绍ODBC的基本概念以及DM4 ODBC DRIVER的使用方法,以便用户更好地使用DM4 ODBC编写应用程序.ODBC提供给你访 ...
随机推荐
- 利用sdkman安装kotlin和java环境
如果想在命令行下面运行kotlin程序,最省事的办法就是用sdkman来安装了: 1.安装sdkman: curl -s "https://get.sdkman.io" | bas ...
- ubuntu for win10 里运行apache+php
一直想试试ubuntu for win10中运行网站测试一下,弄了好久,今天终于基本弄明白了, ubuntu for win10里的IP就是外面WIN10的IP,在里面建立网站了可以直接在外面WIN1 ...
- [100]linux常用命令参数小结
1.mkdir 2.ls -l -d 显示目录 -F 给文件夹结尾加/标识 -a 以.开头的都是隐藏文件 -rt 按照修改时间倒序排列(最新修改的在最下) ls -lhrt #最新的在下面 3.cd ...
- AdminLTE, Color Admin
AdminLTE, Color Adminhttps://github.com/almasaeed2010/AdminLTE/http://www.seantheme.com/color-admin- ...
- adb devices连接提示 Android offline或unauthorized的解决办法
我有一个华为X1手机,版本是Android 4.2.2(我的手机是Android 4.0版本), 但之前用adb连接(包括usb/tcp)时总莫名其妙出现offline或unauthorized的问题 ...
- C++11 explicit的使用
C++中的explicit关键字只能用于修饰只有一个参数的类构造函数 , 它的作用是表明该构造函数是显示的, 而非隐式的,跟它相对应的另一个关键字是implicit, 意思是隐藏的,类构造函数默认情况 ...
- mysql++ result
在介绍Result之前,先熟悉几个类 Field 用来存储SQL字段信息,主要是关于表字段列属性的判断和获取 class Field { public: ...................... ...
- Lua语法基础（1）---简介、基本数据类型、表达式
我觉得我已经陷入了一个坑内.因为,安装了Lua和SublimeText3编辑器之后,怎么使自己编写的lua代码在untiy内运行起来,是个我完全不了解的机制.先放一放吧.首先,来回顾一下Lua的语法基 ...
- js设置滚动条定位到所属容器的最底部
$('.help-gundongtiao').scrollTop($('.help-gundongtiao')[0].scrollHeight);
- Mac在Finder中显示/usr、/tmp、/var等隐藏目录
Finder中默认是不显示/usr./tmp./var等隐藏目录的,通过在终端中输入一下命令来另其显示: #开启 defaults write com.apple.Finder AppleShowAl ...