Cannot connect to Microsoft Azure from shinyapps.io

问题

I built an Rshiny application that pulls data from Microsoft Azure. My application works locally when I use the 'SQL Server' driver in my connection string, but does not work when I publish the app on shinyapps.io. Based on a suggestion from here, I have been trying to use the 'FreeTDS' driver to connect with Azure when publishing on shinyapps.io but I am not having any luck.

Here is my connection string:

con <- dbConnect(odbc::odbc(),
                 Driver = "FreeTDS",
                 Server = "servername", 
                 Database = "databasename",
                 Uid = "uid",
                 Pwd = "pwd",
                 Port = 1433,
                 TDS_Version = 9.0)

I receive the following error message when using the 'FreeTDS' driver:

Error in value[[3L]](cond) : 
  nanodbc/nanodbc.cpp:950: 08001: [unixODBC][FreeTDS][SQL Server]Unable to connect to data source

I have tried using TDS_Version 7.0, 7.2, 7.4, 9.0 - none have worked. Can anyone help me decode this error message? Thank you!

Note: I am working with R 3.6 on Windows 10. I have whitelisted shinyapps.io IP addresses on Azure, so that is not the issue.

回答1:

The driver requires DSN and PWD to be specified only on the connection string, they cannot be specified in the DSN. http://www.freetds.org/userguide/odbcconnattr.htm

For more details, refer Similar GitHub issue, which addresses similar issue.

Hope this helps.

回答2:

For connecting both on local Windows and Shinyapps.io, this has worked for me:

library(RODBC)

is_local<-Sys.getenv('SHINY_PORT')==""

dbConnector <- function(local=FALSE){
    if(local){dbConn <- odbcDriverConnect("Driver=ODBC Driver 13 for SQL Server;Server=xxx.database.windows.net,1433;Database=xxxxxxxxx;Uid=xxxx;Pwd=xxxxxxxxx;Encrypt=yes;TrustServerCertificate=no;Connection Timeout=30")
        } else {dbConn <- odbcDriverConnect("Driver=FreeTDS;TDS_Version=8.0;Server=xxxx.database.windows.net; Port=1433;Database=xxxxx;Uid=xxxxxx;Pwd=xxxxxxxxx;Encrypt=yes;TrustServerCertificate=no;Connection Timeout=30")}
}
dbConn <- dbConnector(is_local)

来源：https://stackoverflow.com/questions/56486557/cannot-connect-to-microsoft-azure-from-shinyapps-io

标签

azure

Shiny

odbc

shinyapps