防止dplyr加入NA

I'd like to do a full-join of 2 df's. To my surprise, dplyr's default behavior is to join on NA's if they exist in both df's. Is there a functionality to prevent dplyr from doing this?

我想完全加入2 df。令我惊讶的是，dplyr的默认行为是加入NA，如果它们存在于两个df中。是否有防止dplyr执行此操作的功能？

Here's an example with inner join:

以下是内部联接的示例：

x <- data.frame(a = c(5, NA, 9), b = 1:3)
y <- data.frame(a = c(5, NA, 9), c = 4:6)
z <- dplyr::inner_join(x, y, by = 'a')

I would like z to contain only 2 records, not 3. Ideally, I want to do this without having to manually filter out the records with NA's beforehand and then append them to the result (since that seems clumsy).

我希望z只包含2条记录，而不是3.理想情况下，我想这样做而不必事先用NA手动过滤掉记录，然后将它们附加到结果中（因为这看起来很笨拙）。

1 个解决方案

#1

You can use na_matches = "never". This is in the NEWS for v. 0.7.0 but I don't see it in the documentation. The default is na_matches = "na".

你可以使用na_matches =“never”。这是针对v.7.0.0的新闻，但我没有在文档中看到它。默认值为na_matches =“na”。

This returns two rows instead of three:

这将返回两行而不是三行：

dplyr::inner_join(x, y, by = 'a', na_matches = "never")

  a b c
1 5 1 4
2 9 3 6

#1