无法在PostgreSQL中使用RPostgres dbWriteTable编写时间戳

Question

我试图使用tibble包将Rdata.frame对象(或data.frame)写入Postgres数据库。在文档之后，我尝试使用dbWriteTable函数。

但是，我意识到该方法中没有field.types的规范。在这里，我提供了一个最小的示例，当输入具有POSIXct时间戳时(以及当时间戳被解释为字符时传递)，您可以看到方法失败。

library(dplyr)
library(DBI)
library(RPostgres)
library(tibble)

conn <- dbConnect(RPostgres::Postgres(),
  host = url$host,
  port = url$port,
  dbname = url$dbname,
  user = url$user,
  password = url$password
)

test <- tibble(
  words = c("hallo","ja", "nein"),
  value = c(3,4,5),
  time= as.POSIXct(c("2016-05-04 04:32","2016-06-02 09:37","2016-07-12 10:43")))
test2 <- tibble(
  words = c("hallo","ja", "nein"),
  value = c(3,4,5),
  time= c("2016-05-04 04:32","2016-06-02 09:37","2016-07-12 10:43"))

dbWriteTable(conn = conn, name = "words", value = test)
> Error in eval(substitute(expr), envir, enclos) :
> ERROR:  invalid input syntax for type real: "2016-05-04 04:32:00"
> CONTEXT:  COPY words, line 1, column time: "2016-05-04 04:32:00"

dbWriteTable(conn = conn, name = "words2", value = test2)
> [1] TRUE

有谁知道用Postgres使用R编写带有时间戳的表的更好方法吗？

Answer 1

在PostgreSQL包中使用RPostgreSQL驱动程序是可行的。另外，第三个时间戳的格式与as.POSIXct的默认格式不匹配--小时的数字太多。因此，我将"2016-07-12 010:43"改为"2016-07-12 10:43"，您应该会发现它运行良好。

library(dplyr)
library(DBI)
library(RPostgreSQL)
library(tibble)

#connect to db    
url <- list(user="postgres",password="postgres",dbname="test")

conn <- dbConnect(drv="PostgreSQL", user=url$user, password=url$password, dbname = url$dbname)


test <- tibble(
  words = c("hallo","ja", "nein"),
  value = c(3,4,5),
  time= as.POSIXct(c("2016-05-04 04:32","2016-06-02 09:37","2016-07-12 10:43")))
test2 <- tibble(
  words = c("hallo","ja", "nein"),
  value = c(3,4,5),
  time= c("2016-05-04 04:32","2016-06-02 09:37","2016-07-12 010:43"))


dbWriteTable(conn = conn, name = "words", value = test)

1真

dbWriteTable(conn = conn, name = "words2", value = test2)

1真

dbDisconnect(conn)