Accessing MySQL Database in R

Thu, Jan 20, 2011 8:30 AM

The following worked for me recently:


library(RMySQL)
MySQL. <- MySQL()
MySQLcon <- dbConnect(MySQL., user='thisuser', password='thispassword',
                       dbname='desiredDB')


       I have the following suggestions and questions for you:


             1.  Have you tried supplying "dbname" rather than "host"?


             2.  Please provide "sessionInfo()".  Many packages have a 
function named "dbConnect", and I don't know which one you are using.


             3.  I don't know if "MySQL()" is equivalent to 
dbDriver("MySQL"), which you used.  It might be;  I don't know.


             4.  The standard "install.packages('RMySQL')" may not work, 
because this package needs to be built to configure itself properly to 
your local operating system and versions of MySQL and R installed.  
Installation instructions are available at 
"http://biostat.mc.vanderbilt.edu/wiki/Main/RMySQL".  If you have not 
already followed those instructions, please do so.  There is a good 
chance that will fix your problem, I think.


             5.  If this is not adequate, I suggest you post this 
question to "r-sig-db at stat.math.ethz.ch".  [I suggest you subscribe 
first.  This list has low volume and you can unsubscribe later if you 
prefer.  And please also provide "sessionInfo()".]


             6.  Or use RODBC as suggested by Ptit Bleu.  It comes 
highly recommended (including by Brian Ripley).  However, I had 
difficulties getting positive results from both RMySQL and RODBC.  I 
tried both, with each receiving similar quantities of expletives.  
Finally, I got RMySQL to do what I wanted and suspended my schoolboy 
exercises with RODBC.


       Hope this helps.
       Spencer

On 1/20/2011 5:55 AM, PtitBleu wrote:

Hello,

I used to use RMySQL but as there is no more package for windows, I decided
to move to RODBC.
I installed ODBC driver for MySQL (downloaded on the MySQL website) and then
the RODBC package.

I finally discovered that it was not needed to "register" your database with
ODBC before using it.
These commands below work for me.

library(RODBC)
ch<-odbcDriverConnect(connection="SERVER=localhost;DRIVER=MySQL ODBC 5.1
Driver;DATABASE=my_database;UID=root;PWD=my_password;case=tolower")
resultdb<-sqlQuery(ch,"SELECT * from my_table")
odbcClose(ch)

Try to modify them for your case.
I hope it will work for you.
Good luck,
Ptit Bleu.


Re: Accessing MySQL Database in R
Jan 18, 2011; 12:10am ? by djmuseR [User is online] djmuseR
Hi:

Because R does not have a direct interface to MySQL?

You need to load a communication package - the two most common ones are
RODBC and RMySQL. The former requires that you register your MySQL database
table(s) with ODBC before using the RODBC package on them, whereas the
latter works with specific version combinations of MySQL and R. The RODBC
package has a very informative vignette; for information re the RMySQL
package, see
http://biostat.mc.vanderbilt.edu/wiki/Main/RMySQL

HTH,
Dennis

On Mon, Jan 17, 2011 at 1:30 PM, schlafly<[hidden email]>  wrote:

I have a local installation of MySQL on my computer.

I enter the following to access MySQL from the command line:
/Applications/MAMP/Library/bin/mysql -h localhost -u root -p
I am then prompted for a password, and I use: root
This connects me to MySQL in the command line.

I now want to access MySQL databases in R. I enter the following:
mysql<- dbDriver("MySQL")
conn<- dbConnect(mysql,user='root',host='localhost', password='root')

I get the following error message: Error in mysqlNewConnection(drv, ...) :
RS-DBI driver: (Failed to connect to database: Error: Access denied for
user
'root'@'localhost' (using password: YES)

Does anyone know why these aren't equivalent?
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Accessing MySQL Database in R

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