r - 无法使用 dplyr db_write_table() 将数据附加到 sqlite3

Question

使用 dplyr 向表中添加数据时，我看到了 https://stackoverflow.com/a/26784801/1653571但文档说 db_insert_table() 已弃用。

?db_insert_into()

...
db_create_table() and db_insert_into() have been deprecated in favour of db_write_table().
...

我尝试使用未弃用的 db_write_table() 来代替，但是无论有没有 append= 选项，它都失败了:

require(dplyr)

my_db <- src_sqlite( "my_db.sqlite3", create = TRUE)                 # create src
copy_to( my_db, iris, "my_table", temporary = FALSE)                 # create table
newdf = iris                                                         # create new data

db_write_table( con = my_db$con, table = "my_table", values = newdf) # insert into
# Error: Table `my_table` exists in database, and both overwrite and append are FALSE

db_write_table( con = my_db$con, table = "my_table", values = newdf,append=True) # insert into
# Error: Table `my_table` exists in database, and both overwrite and append are FALSE

是否可以使用 db_write_table() 追加数据？

另见 https://github.com/tidyverse/dplyr/issues/3120

Answer 1

不，您不应该使用 db_write_table() 而不是 db_insert_table()，因为它不能跨后端泛化。

并且您不应该使用 tidyverse 版本而不是相关的 DBI:::版本，因为 tidyverse 辅助函数供内部使用，并没有设计得足够健壮以供用户使用。请参阅 https://github.com/tidyverse/dplyr/issues/3120#issuecomment-339034612 的讨论:

Actually, I don't think you should be using these functions at all. Despite that SO post, these are not user facing functions. You should be calling the DBI functions directly.
-- Hadley Wickham, package author.