Extract a dplyr tbl column as a vector

With dplyr >= 0.7.0, you can use pull() to get a vector from a tbl.

library(dplyr, warn.conflicts = FALSE)
db <- src_sqlite(tempfile(), create = TRUE)
iris2 <- copy_to(db, iris)
vec <- pull(iris2, Species)
head(vec)
#> [1] "setosa" "setosa" "setosa" "setosa" "setosa" "setosa"