与ROracle连接时出现无效连接错误

Question

下面是我试图在rstudio中运行并得到以下错误的代码，可以有人指出我的错误:

Warning: Error in .oci.GetQuery: invalid connection Stack trace (innermost first): 84: .oci.GetQuery 83: .local 82: dbGetQuery 81: dbGetQuery 80: getqdata [P:/EI_DBA_Engineering/ShinyR/EI/App5/apptest.r#51] 79: ggplotly [P:/EI_DBA_Engineering/ShinyR/EI/App5/apptest.r#56] 78: func 77: origRenderFunc 76: output$dynamicPlot 1: runApp 下面的代码试图连接到数据库并检索数据，我在连接时得到错误。

    require(ggplot2)
require(scales)
require(reshape)
require(ROracle)
require(shiny)
library(plotly)
ui <- dashboardPage(
  skin="green",
  dashboardHeader(title = "Real Time Dashboard for EI"),
  dashboardSidebar(disable = TRUE),
  dashboardBody(
    fluidRow(
      # A stati"c valueBox
      #column(5,DT::dataTableOutput("text1"))
    ),
    box(
      title = "CPU UTILIZATION DAILY "
      ,status = "primary"
      ,solidHeader = TRUE
      ,collapsible = TRUE
      ,width = "800px"
      ,plotlyOutput('dynamicPlot', height = "300px")
    )
  ))
server <- function(input, output, session) {
  sqlstmt1 <- reactive({
    sqlstmt1 <- paste0("select instance_name from v$instance")
    print (sqlstmt1)
    return(sqlstmt1)
  })
  con <- reactive({
    drv <- dbDriver("Oracle")
    on.exit(dbDisconnect(con))
    con <- dbConnect(drv, dbname = "abcd", username = "aaaaa", password =  "bbbbbbb")
    print (con)
    return(con)
  })
   getqdata <- function (con) {
    print ("inside getn")
    #print (con())
    #print (sqlstmt1()) 
    cat("Refreshing....","n")
    mdat <- dbGetQuery(con,sqlstmt1())
    return(mdat)
  }
  output$dynamicPlot <- renderPlotly({
    p1 <- getqdata(con())
    stout <- t(p1())
    mdata <- melt(p1(), id.var = c("TTIME", "ENTITY_NAME")) 
    print (mdata)
    invalidateLater(10000, session)
    #p1 <- plot_ly(mdata, x = ~TTIME, y = ~value, type = 'scatter', mode = 'lines',  color= ~ENTITY_NAME , fill = 'tozeroy') %>%
     # layout(xaxis = list(title = 'Date',showticklabels = FALSE),
      #     yaxis = list(title = 'CPU Percentage'))
      #ggplotly(p1)
    #invalidateLater(10000, session)
      })
  }
shinyApp(ui, server)

Answer 1

我通过取出on.exit(dbDisconnect(con))