r - 错误：依赖项 'ROracle' 不适用于包 'ora'

Question

我正在尝试安装“ora”包，所以我使用这个命令：

install.packages("ora")

但是，它向我抛出了以下错误，它表明 ROracle 的版本不可行。

installing the source package 'ora'
  trying URL 'https://cran.rstudio.com/src/contrib/ora_2.0-1.tar.gz'
  Content type 'application/x-gzip' length 5815 bytes
  downloaded 5815 bytes

ERROR: dependency 'ROracle' is not available for package 'ora'
* removing 'C:/Users/samora/Documents/R/R-3.5.1/library/ora'
In R CMD INSTALL
Warning in install.packages :
  installation of package ‘ora’ had non-zero exit status

The downloaded source packages are in
    ‘C:\Users\samora\AppData\Local\Temp\RtmpIxcR0T\downloaded_packages’

所以我尝试更新它，但在这样做之后，继续错误。

你可以帮帮我吗？