R中的个人数据库连接包

Question

I have created a package to simplify the process of establishing a database connection when I begin a new project in R. Nearly every project requires me to connect to a proprietary database, which means looking back into files and copy-pasting in what I had done before and copying the sql drivers into the new project folder. Ideally I would like to start a new project with the following code:

library(MyConnections)

conn <- MyConnections::get_conn()

I have a package function that works for database connections that does not require me to read a driver file.

get_mysql_conn <- function(){
  require(RMySQL)
  dbConnect(MySQL(),
            user = 'user',
            password = "password",
            dbname = 'dbname',
            host= 'host')
}

However, I cannot figure out how to make this code work the way that I want.

get_mssql_conn <- function(){
  require(RJDBC)
  driver <- JDBC("com.microsoft.sqlserver.jdbc.SQLServerDriver", "./drivers/mssql-jdbc-7.0.0.jre8.jar")
  dbConnect(driver, "[connection string]",'[user]')
}

I assume there must be a way to create the driver object in the package and use it in the function in place of reading the file, but I am entirely lost as to how I go about that. Any help or a pointing in the correct direction would be much appreciated.

Answer 1

You can create a directory inst/drivers and save the .jar file there, then create your function as below:

get_mssql_conn <- function(){
  driver <- RJDBC::JDBC(
    "com.microsoft.sqlserver.jdbc.SQLServerDriver", 
    system.file("drivers", "mssql-jdbc-7.0.0.jre8.jar", package = "MyConnections")
  )
  RJDBC::dbConnect(driver, "[connection string]",'[user]')
}

Side note: you should never use require or library in an R package -- always use :: and list the package in the Imports in the DESCRIPTION file.