如何使用RPostgresql写入和读取二进制数据

问题描述

我正在尝试执行代码:

连接到服务器

library('RPostgreSQL', quietly = TRUE)
kHostName  <- '...'
kPort      <- '5432'
kDBName    <- '...'
kUser      <- '...'
kPassword  <- '...'

drv <- dbDriver("PostgreSQL")
con <- dbConnect(drv,
                 host      = kHostName,
                 port      = kPort,
                 dbname    = kDBName,
                 user      = kUser,
                 password  = kPassword)

以下部分代码摘自 https://groups .google.com/forum/#！topic/rpostgresql-dev/lPPmS8yeP9w 和 https://github.com/codeinthehole/rpostgresql/blob/master/RPostgreSQL/tests/bytea.R

dbGetQuery(con,"CREATE TABLE byteatable (name text NOT NULL, val bytea,
PRIMARY KEY (name))")
sample.object <- list("one","two");
ser <- serialize(sample.object,NULL,ascii=F);
postgresqlEscapeBytea(con, ser)
iq <- sprintf("INSERT INTO byteatable values('%s',E'%s');","name1", postgresqlEscapeBytea(con, ser))
dbGetQuery(con, iq)
rows<-dbGetQuery(con, "SELECT * from byteatable")
ser2<-postgresqlUnescapeBytea(rows[[2]])

它返回:

Error: could not find function "postgresqlEscapeBytea"

我如何使它工作?

我使用:

> version
               _
platform       x86_64-apple-darwin13.4.0
arch           x86_64
os             darwin13.4.0
system         x86_64, darwin13.4.0
status
major          3
minor          3.0
year           2016
month          05
day            03
svn rev        70573
language       R
version.string R version 3.3.0 (2016-05-03)
nickname       Supposedly Educational

推荐答案

据我所知，函数postgresqlUnescapeBytea仅在RpostgreSQL包的开发版本中可用，可以在此处下载: https://github.com/codeinthehole/rpostgresql

The function postgresqlUnescapeBytea is only available in the development version of the RpostgreSQL package as far as I'm aware, which can be downloaded here: https://github.com/codeinthehole/rpostgresql

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