sqliteSendQuery（con，statement，bind.data）中的错误：过期的SQLiteConnection

Question

我正在尝试构建一个闪亮的应用程序，第一个使用renderUI从SQLite填充的下拉菜单。

以下是我的server.r

library("shiny")
library("RSQLite")

shinyServer(function(input, output) {


db<-dbConnect(SQLite(),"PNL.sqlite")


origins<-data.frame(dbGetQuery(db,"SELECT Origin_Name from CNS_Origin_List"))

output$origin<-renderUI({
  selectInput(inputId = "origin",label = "Select Origin",choices = origins$Origin_Name)
})


query<-reactive({
                 sql<-dbGetQuery(db,paste0('SELECT Region_Name from CNS_Origin_List Where Origin_Name ="',input$origin,'"'))
})





#This is where the error occurs when I call the query()
output$region<-renderTable(query())


dbDisconnect(db)
})

这是我的ui.R

library(shiny)

# Define UI for application that draws a histogram
shinyUI(fluidPage(

  # Application title
  titlePanel("PNL Calculator!"),

  # Sidebar with a slider input for the number of bins
  fluidRow(
    column(4,
           wellPanel(
             uiOutput(outputId = "origin"))),

    column(6,
           wellPanel(
             tableOutput(outputId = "region"),

           )
           )
    )

))

我得到了

Error in sqliteSendQuery(con, statement, bind.data) : 
  expired SQLiteConnection

不确定我哪里出错了。请帮忙

Answer 1

我猜测代码末尾的dbDisconnect(db)是否会在应用程序结束时与数据库断开连接。您应该使用session$onSessionEnded。

http://shiny.rstudio.com/reference/shiny/latest/session.html

How to implement a cleanup routine in R Shiny?

Timing events when session ends