Question

我想在Shiny中的反应上下文中运行mongolite查询。 db连接参数已预先加载，未在下面显示。（注意：loadData函数出现在第一个代码块中）。查询在反应性上下文之外运行得很好。

我似乎无法在网上找到一个与Shiny和mongolite一起工作的工作示例。任何帮助将不胜感激。在下面的简化示例中，我只是想让Shiny返回查询结果中的行数。

由于

loadData <- function() {
  # Connect to the database
  db <- mongo(collection = collectionName,
              url = sprintf(
                "mongodb://%s:%s@%s/%s",
                options()$mongodb$username,
                options()$mongodb$password,
                options()$mongodb$host,
                databaseName))
  # Read all the entries
  data <- db$find(query)
  data
}


server <- function(input, output) {

   queryResults <- reactive({

    ########----------BRING IN USER QUERY PARAMETERS----------########
    var1 <- "satisfaction"
    var2 <- "performance"
    var1path <- 20072
    var2path <- 30033

    ########----------DEFINE QUERY PARAMETERS----------########
    var1 <- as.character(var1)
    var1 <- paste(var1, collapse = "|")
    var1JSON <- toJSON (var1)

    var2 <- as.character(var2)
    var2 <- paste(var2, collapse = "|")
    var2JSON <- toJSON (var2)

    #-----Creating JSONs for taxonomy codes

    var1path <- as.character(var1path)
    var1path <- paste(var1path, collapse = "|")
    var1path <- toJSON (var1path)

    var2path <- as.character(var2path)
    var2path <- paste(var2path, collapse = "|")
    var2path <- toJSON (var2path)

    ########----------QUERY STRUCTURE AND EXECUTION----------#########
    query <- c('
               {"$and":
               [
               {"$or":
               [ 
               {"Var1": { "$regex": ',var1JSON,' }},
               {"Var1Path": { "$regex": ',var1path,' }}
               ]
               },

               {"$or":
               [
               {"Var2": { "$regex": ',var2JSON,' }},
               {"Var2Path": { "$regex": ',var2path,' }}
               ]
               }
               ]
               }
               ')

    stuff <- loadData()
    stuff
  })

  output$text1 <- renderText(nrow(queryResults()))

Answer 1

由于我无法重现您的代码，因此我需要设置自己的数据，但希望这会向您展示mongolite＆amp; shiny。

数据

将一些数据输入mongodb

library(mongolite) ## create dummy data df <- data.frame(id = c(1,2,3), region = c("r1", "r1", "r2")) > df id region 1 1 r1 2 2 r1 3 3 r2 ## insert into database mong <- mongo(collection = "test", db = "test", url = "mongodb://localhost") mong$insert(df) # Complete! Processed total of 3 rows. # [1] TRUE

<强>光泽

这是一个响应用户输入的非常基本的应用程序。我试图与你的结构保持一致

<强> server.R

library(shiny) library(jsonlite) library(mongolite) loadData <- function(qry){ mong <- mongo(collection = "test", db = "test", url = "mongodb://localhost", verbose = TRUE) df <- mong$find(qry) return(df) } shinyServer(function(input, output) { qryResults <- reactive({ ## This bit responds to the user selection ## which makes it 'reactive' region <- list(region = input$si_region) qry <- paste0('{ "region" : "',region , '"}') df <- loadData(qry) return(df) }) output$qry_results <- renderDataTable({ qryResults() }) output$text1 <- renderText(nrow(qryResults())) })

<强> ui.R

library(shiny) shinyUI(navbarPage("mongo query", sidebarLayout( sidebarPanel( selectInput(inputId = "si_region", label = "Select region", choices = c("r1", "r2")) ), mainPanel( verbatimTextOutput(outputId = "text1"), dataTableOutput(outputId = "qry_results") ) )))

闪亮的mongolite查询

1 个答案: