`[.data.frame`（x，by）中出错：选择了未定义的列 #为规范化目的读取参考数据 setwd（“../database”） 您缺少一个逗号 t_dailyoutage请提供您的问题的最小可复制示例-有一个指南。特别是，请显示出现错误的行，这样我

`[.data.frame`（x，by）中出错：选择了未定义的列

#为规范化目的读取参考数据
setwd（“../database”）
您缺少一个逗号

t_dailyoutage请提供您的问题的最小可复制示例-有一个指南。特别是，请显示出现错误的行，这样我们就不必花太多时间在代码中查找错误
     # Read reference data for normalization purposes
    setwd("../database")
    r_status <- read.csv("r_status.csv", stringsAsFactors = FALSE, na.strings = c("NA",""))
    r_status <- subset(r_status, select = c(status_id, status, status_datasource))
    
    t_location <- read.csv("t_location.csv", stringsAsFactors = FALSE, na.strings = c("NA",""))
    t_location$location <- t_location$location_description
    t_location$location <- as.numeric(gsub("^.*-", "", t_location$location))
    t_location <- t_location[!is.na(t_location$location),]
    t_location <- subset(t_location, select = c(location_id, location_description, location))
    
    # Read the database tables that store daily report data
    setwd("../database")
    t_dailyoutage <- read.csv("t_dailyoutage.csv", stringsAsFactors = FALSE, na.strings = c("NA",""))
    t_dailysensor <- read.csv("t_dailysensor.csv", stringsAsFactors = FALSE, na.strings = c("NA",""))  
     # Denormalize
        if(nrow(t_dailyoutage) > 0) {
                t_dailyoutage  <- join(t_dailyoutage, r_status, by = "status_id",) %>% 
                        join(t_location, by="location_id")
t_dailyoutage <-  t_dailyoutage[c("location", "status", "report_time", 
                                  "dailyoutage_inserted", "dailyoutage_inserted_by", "dailyoutage_updated")]
               
        }