我已经安装了R3.0.1。还安装了Rtools。已安装MySQL 5.7版。我想将R连接到MySQL，我正在尝试通过R中的RMySQL包来实现。
在查看了各种SO问题之后终于完成了RMySQL的安装，但library命令给出了错误。请参阅以下完整的R日志。请帮忙。
> install.packages("RMySQL",type="source")
trying URL 'http://cran.rstudio.com/src/contrib/RMySQL_0.9-3.tar.gz'
Content type 'application/x-gzip' length 165363 bytes (161 Kb)
opened URL
downloaded 161 Kb
* installing *source* package 'RMySQL' ...
** package 'RMySQL' successfully unpacked and MD5 sums checked
checking for $MYSQL_HOME... C:/Program Files/MySQL/MySQL Server 5.7
cygwin warning:
MS-DOS style path detected: C:/Program
Preferred POSIX equivalent is: /cygdrive/c/Program
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
test: Files/MySQL/MySQL: unknown operand
** libs
Warning: this package has a non-empty 'configure.win' file,
so building only the main architecture
cygwin warning:
MS-DOS style path detected: D:/SOFTWA~1/R-30~1.3/etc/x64/Makeconf
Preferred POSIX equivalent is: /cygdrive/d/SOFTWA~1/R-30~1.3/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"D:/SOFTWA~1/R-30~1.3/include" -DNDEBUG -I"C:/Program Files/MySQL/MySQL Server 5.7"/include -I"d:/RCompile/CRANpkg/extralibs64/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"D:/SOFTWA~1/R-30~1.3/include" -DNDEBUG -I"C:/Program Files/MySQL/MySQL Server 5.7"/include -I"d:/RCompile/CRANpkg/extralibs64/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 C:/Program Files/MySQL/MySQL Server 5.7/bin/libmySQL.dll - Ld:/RCompile/CRANpkg/extralibs64/local/lib/x64 -Ld:/RCompile/CRANpkg/extralibs64/local/lib -LD:/SOFTWA~1/R-30~1.3/bin/x64 -lR
installing to D:/Softwares/R-3.0.3/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 C:/Program Files/MySQL/MySQL Server 5.7
* DONE (RMySQL)
The downloaded source packages are in
‘C:\Users\mitrabhanu.panda\AppData\Local\Temp\RtmpgZHT8R\downloaded_packages’
> library(RMySQL)
Looking in C:\Program Files/MySQL, C:/MySQL, D:/MySQL, E:/MySQL, F:/MySQL, G:/MySQL, C:/xampp/MySQL, D:/xampp/MySQL, E:/xampp/MySQL, F:/xampp/MySQL, G:/xampp/MySQL, C:/Apps/MySQL, D:/Apps/MySQL, E:/Apps/MySQL, F:/Apps/MySQL, G:/Apps/MySQL
Found C:\Program Files/MySQL
Error : .onLoad failed in loadNamespace() for 'RMySQL', details:
call: setwd(bin)
error: character argument expected
Error: package or namespace load failed for ‘RMySQL’
请让我知道我做错了什么。
最佳答案
正如我的评论中所写，这是从mysql中读取表的示例代码：
require(RJDBC)
j <- JDBC(classPath='/path/to/mysql/jdbc/jar', driverClass='com.mysql.jdbc.Driver')
connection <- dbConnect(j, 'jdbc:mysql://localhost/databasename', 'myusername','mypassword')
on.exit(dbDisconnect(connection))
data.frame.from.sql <- dbReadTable(connection, 'tablename')
这会将名为tablename的表从databasename读取为data.frame.from.sql，作为R数据框，您可以根据需要进行操作。我希望这有帮助。
关于mysql - R库RMySQL无法启动，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/25590156/