How do I install RODBC so that is uses unixODBC? - sql-server

Question

After installing and configuring FreeTDS and unixODBC and confirming they are working correctly, I am trying to configure RODBC. However, I am getting the following results when attempting to view the ODBC data sources in the R console.
> odbcDataSources()
named character(0)
If I attempt to use the FreeTDS driver I get the following results.
>odbcDriverConnect("driver={FreeTDS};server=xx.xx.xx.xx;port=1433;database=XXXX_Analysis;trusted_connection=true;UID=********;PWD=********") :
[RODBC] ERROR: state IM003, code 0, message [iODBC][Driver Manager]Specified driver could not be loaded
Based on the error, it looks like RODBC is trying to use iODBC instead of unixODBC. I am not sure how to configure RODBC to use unixODBC.

Answer 1

The proper way to do this is to specify the odbc manager to the package's configure script, like this
install.packages("RODBC",
type = "source",
INSTALL_opts="--configure-args='--with-odbc-manager=odbc'"
)
--with-odbc-manager=odbc indicates you want to use unixODBC
--with-odbc-manager=iodbc indicates you want to use iODBC

Answer 2

I also had this issue after configuring unixODBC on Mac OS 10.13.3 High Sierra. I tried configuring my .Renviron to set an R-specific environment variable for ODBCINI, but RODBC still wouldn't list my data source names (DSNs). Additionally, I couldn't get it to find the driver specified in ODBCinst.ini or even get a connection string working with RODBC::ODBCDriverConnect(), despite being able to connect with isql.
What ended up working was simply:
remove.packages('RODBC')
install.packages('RODBC', type="source")
It seems if you install RODBC from source on mac, it picks up on the odbc.ini file and odbcinst.ini file correctly.
Thanks to this post's subtle comment for unlocking the key:
http://eriqande.github.io/2014/12/19/setting-up-rodbc.html

Answer 3

Turns out the default RODBC package install won't work with unixODBC. Here is a process for recompiling and installing RODBC.
Remove current generic RODBC package via the R console.
>remove.packages("RODBC")
Removing package from ‘/Library/Frameworks/R.framework/Versions/3.4/Resources/library’
(as ‘lib’ is unspecified)
Download the source for RODBC.
https://cran.r-project.org/src/contrib/RODBC_1.3-15.tar.gz
Set the environment variable DYLD_LIBRARY_PATH to the location where your unixODBC library is located. I used homebrew to install unixODBC so my my library is located in /usr/local/lib.
export DYLD_LIBRARY_PATH=/usr/local/lib
Now reinstall RODB so it picks up the new library location.
R CMD INSTALL /Users/xxxxxx/Downloads/RODBC_1.3-15.tar.gz
There is quite a bit of output but look towards the end and you should see something like this.
clang -dynamiclib -Wl,-headerpad_max_install_names -undefined dynamic_lookup -single_module -multiply_defined suppress -L/Library/Frameworks/R.framework/Resources/lib -L/usr/local/lib -o RODBC.so RODBC.o -lodbc -F/Library/Frameworks/R.framework/.. -framework R -Wl,-framework -Wl,CoreFoundation
installing to /Library/Frameworks/R.framework/Versions/3.4/Resources/library/RODBC/libs
** R
** inst
** preparing package for lazy loading
** help
*** installing help indices
** building package indices
** installing vignettes
** testing if installed package can be loaded
* DONE (RODBC)
Notice the -L/usr/local/lib indicating the library location was picked up.
Now you should be able to see your ODBC connections provided by unixODBC. Back in the restarted R console you can type the following to verify RODBC is using unixODBC.
> library("RODBC")
> odbcDataSources()
MYMSSQL1 MYMSSQL XXXXXXXXX_C_DB XXXXXXXX-SQL1
"FreeTDS" "FreeTDS" "FreeTDS" "FreeTDS"
Thanks to hiltmon for helping put me on the right track.