r: escape single quote in a string

Question

I have a string like a <- "abc'def" and I need to paste this into a longer sql string:

 s <- paste0("select * from x where xx ='", a, "'")

But the single quote in the middle makes it fail, I cannot manually replace ' with \\' but need to use a function.

Answer 1

你需要逃离'在a适当的到数据库的东西，而不是R.这可能将是它加倍： '' 。

Answer 2

In many SQL implementations, doubling achieves the escaping you want:

a <- "abc'def"
a <- gsub("'", "''", a)
s <- paste0("select * from x where xx ='", a, "'")

[1] "select * from x where xx ='abc''def'"