R 动态查询与闪亮的应用程序

我想构建一个连接到数据库的闪亮应用程序，我的问题是如何动态创建查询，这里我举了一个例子，其中用户有四个研究轴，您只需要在R环境中复制代码，但在我的应用程序中，我有12个研究轴，如果您有想法，我不知道如何管理查询

# rm(list=ls())
library(sqldf)
library(car)
data(Moore)
ContextElements = colnames(Moore)
ContextElements[1] = 'partner_status'
library(shiny)
runApp(list(
ui = shinyUI(fluidPage(

titlePanel(h3("Data Select", style="background-color:gray")),
hr(),
div(class="row-fluid", style="height=350px; background-color:lightgray",
    column(width=3,
           uiOutput("firstAxe"),
           uiOutput("firstAxeOutput")
    ),
    column(width=3,
           uiOutput("secondAxe"),
           uiOutput('type1'),
           uiOutput("secondAxeOutput")
    ),
    column(width=3,
           uiOutput("thirdAxe"),
           uiOutput('type2'),
           uiOutput("thirdAxeOutput")
    ),
    column(width=3,
           uiOutput("fourthAxe"),
           uiOutput('type3'),
           uiOutput("fourthAxeOutput")
    )
),
hr(),
hr(),
div(class="row-fluid",
    column(12,
           verbatimTextOutput("mainQuery"))),
hr(),
div(class="row-fluid",
    column(12,
           verbatimTextOutput("query1"))),
div(class="row-fluid",
    column(12,
           verbatimTextOutput("query2"))),
div(class="row-fluid",
    column(12,
           verbatimTextOutput("query3")))

)),
server=function(input, output){
buildQuery= reactive({

})
output$mainQuery = renderPrint(buildQuery())
###############
### first Axis
output$firstAxe= renderUI({
  selectInput(inputId = "firstAxe", label = h4("First Axis"), 
              choices=c(Choose='',ContextElements), multiple = FALSE) 
})    
# output Query
output$firstAxeOutput=renderUI({
  if(!is.null(input$firstAxe)){
    if(input$firstAxe==""){
      selectInput(inputId = "firstAxeOutput", label="", choices = NULL,   multiple = TRUE, selectize = FALSE)
    }else{
      query = paste('select distinct ', input$firstAxe, ' from Moore order by ', input$firstAxe, sep='')
      choicesValues = sqldf(query)
      selectInput(inputId = "firstAxeOutput", label="", choices = choicesValues[[1]], multiple = TRUE, selectize = FALSE)
    } 
  }          
})
###############
### second Axis
precAxeRes1 =reactive(paste(input$firstAxeOutput, collapse = "','"))
output$type1 = renderPrint(precAxeRes1())
output$secondAxe= renderUI({
  firstSel = input$firstAxe
  ContextElements = setdiff(ContextElements, firstSel)
  selectInput(inputId = "secondAxe", label = h4("Second Axis"), 
              choices=c(Choose='',ContextElements), multiple = FALSE) 
})
# output Query
output$secondAxeOutput=renderUI({      
  if(!is.null(input$secondAxe)){
    if(input$secondAxe=="" || input$firstAxe==""){
      selectInput(inputId = "secondAxeOutput", label="", choices = NULL, multiple = TRUE, selectize = FALSE)
    }else{
      if(is.null(input$firstAxeOutput)){
        query = paste('select distinct ', input$secondAxe, ' from Moore  where ',
                      input$firstAxe, " like ('%') order by ",   input$secondAxe , sep='')
        #             query = paste('select distinct ', input$secondAxe, ' from Moore order by ', input$secondAxe, sep='')  
      }else{
        query = paste('select distinct ', input$secondAxe, ' from Moore where ',
                      input$firstAxe, " in ('",precAxeRes1(), "') order by ", input$secondAxe , sep='') 
      }          
      choicesValues = sqldf(query)
      output$query1 = renderPrint(paste("Second Query: ",query))
      selectInput(inputId = "secondAxeOutput", label="", choices = choicesValues[[1]], multiple = TRUE, selectize = FALSE)
    } 
  } 
})
###############
### third Axis
precAxeRes2 =reactive(paste(input$secondAxeOutput, collapse = "','"))
output$type2 = renderPrint(precAxeRes2())
output$thirdAxe= renderUI({
  precSel = c(input$firstAxe, input$secondAxe)
  ContextElements = setdiff(ContextElements, precSel)
  selectInput(inputId = "thirdAxe", label = h4("Third Axis"), 
              choices=c(Choose='',ContextElements), multiple = FALSE) 
})
# output Query
output$thirdAxeOutput=renderUI({
  if(!is.null(input$thirdAxe)){
    if(input$thirdAxe=="" || input$secondAxe==""){
      selectInput(inputId = "thirdAxeOutput", label="", choices = NULL, multiple = TRUE, selectize = FALSE)
    }else{
      if(is.null(input$firstAxeOutput) && is.null(input$secondAxeOutput)){
        query = paste('select distinct ', input$thirdAxe, ' from Moore where ',
                      input$firstAxe,  " like ('%') and ",
                      input$secondAxe, " like ('%') order by " , input$thirdAxe,
                      sep='')
      }else if(!is.null(input$firstAxeOutput) && is.null(input$secondAxeOutput)){
        query = paste('select distinct ', input$thirdAxe, ' from Moore where ',
                      input$firstAxe,  " in ('",precAxeRes1(), "') and ",
                      input$secondAxe, " like ('%') order by " , input$thirdAxe,
                      sep='')
      }else if(is.null(input$firstAxeOutput) && !is.null(input$secondAxeOutput)){
        query = paste('select distinct ', input$thirdAxe, ' from Moore where ',
                      input$firstAxe,  " like ('%') and ",
                      input$secondAxe, " in ('",precAxeRes2(), "') order by " , input$thirdAxe,
                      sep='')
      }else{
        query = paste('select distinct ', input$thirdAxe, ' from Moore where ',
                      input$firstAxe,  " in ('",precAxeRes1(), "') and ",
                      input$secondAxe, " in ('",precAxeRes2(), "') order by " , input$thirdAxe,
                      sep='')
      }         
      choicesValues = sqldf(query)
      output$query2 = renderPrint(paste("Third Query: ",query))
      selectInput(inputId = "thirdAxeOutput", label="", choices = choicesValues[[1]], multiple = TRUE, selectize = FALSE)
    } 
  } 
})
###############
### fourth Axis
precAxeRes3 =reactive(paste(input$thirdAxeOutput, collapse = "','"))
output$type3 = renderPrint(precAxeRes3())
output$fourthAxe= renderUI({
  precSel = c(input$firstAxe, input$secondAxe, input$thirdAxe)
  ContextElements = setdiff(ContextElements, precSel)
  selectInput(inputId = "fourthAxe", label = h4("Fourth Axis"), 
              choices=c(Choose='',ContextElements), multiple = FALSE) 
})
# output Query
output$fourthAxeOutput=renderUI({
  if(!is.null(input$fourthAxe)){
    if(input$fourthAxe=="" || input$thirdAxe==""){
      selectInput(inputId = "fourthAxeOutput", label="", choices = NULL, multiple = TRUE, selectize = FALSE)
    }else{ 

      if(is.null(input$firstAxeOutput) && is.null(input$secondAxeOutput) && is.null(input$thirdAxeOutput)){
        query = paste('select distinct ', input$fourthAxe, ' from Moore where ',
                      input$firstAxe,  " like ('%') and ",
                      input$secondAxe, " like ('%') and ",
                      input$thirdAxe, " like ('%') order by " , input$fourthAxe,
                      sep='')
        #             query = paste('select distinct ', input$thirdAxe, ' from Moore order by ',  input$thirdAxe, sep='')
      }else if(!is.null(input$firstAxeOutput) && !is.null(input$secondAxeOutput) && is.null(input$thirdAxeOutput)){
        query = paste('select distinct ', input$fourthAxe, ' from Moore where ',
                      input$firstAxe,  " in ('",precAxeRes1(), "') and ",
                      input$secondAxe, " in ('",precAxeRes2(), "') and ",
                      input$thirdAxe, " like ('%') order by " , input$fourthAxe,
                      sep='')
      }else if(!is.null(input$firstAxeOutput) && is.null(input$secondAxeOutput) && !is.null(input$thirdAxeOutput)){
        query = paste('select distinct ', input$fourthAxe, ' from Moore where ',
                      input$firstAxe,  " in ('",precAxeRes1(), "') and ",
                      input$secondAxe, " like ('%') and ",
                      input$thirdAxe, " in ('",precAxeRes3(), "') order by " , input$fourthAxe,
                      sep='')
      }else if(!is.null(input$firstAxeOutput) && is.null(input$secondAxeOutput) && is.null(input$thirdAxeOutput)){
        query = paste('select distinct ', input$fourthAxe, ' from Moore where ',
                      input$firstAxe,  " in ('",precAxeRes1(), "') and ",
                      input$secondAxe, " like ('%') and ",
                      input$thirdAxe, " like ('%') order by " , input$fourthAxe,
                      sep='')
      }else if(is.null(input$firstAxeOutput) && !is.null(input$secondAxeOutput) && !is.null(input$thirdAxeOutput)){
        query = paste('select distinct ', input$fourthAxe, ' from Moore where ',
                      input$firstAxe,  " like ('%') and ",
                      input$secondAxe, " in ('",precAxeRes2(), "') and ",
                      input$thirdAxe, " in ('",precAxeRes3(), "') order by " , input$fourthAxe,
                      sep='')
      }else if(is.null(input$firstAxeOutput) && !is.null(input$secondAxeOutput) && is.null(input$thirdAxeOutput)){
        query = paste('select distinct ', input$fourthAxe, ' from Moore where ',
                      input$firstAxe,  " like ('%') and ",
                      input$secondAxe, " in ('",precAxeRes2(), "') and ",
                      input$thirdAxe, " like ('%') order by " , input$fourthAxe,
                      sep='')
      }else if(!is.null(input$firstAxeOutput) && !is.null(input$secondAxeOutput) && !is.null(input$thirdAxeOutput)){
        query = paste('select distinct ', input$fourthAxe, ' from Moore where ',
                      input$firstAxe,  " in ('",precAxeRes1(), "') and ",
                      input$secondAxe, " in ('",precAxeRes2(), "') and ",
                      input$thirdAxe, " in ('",precAxeRes3(), "') order by " , input$fourthAxe,
                      sep='')
      }else{
        query = paste('select distinct ', input$fourthAxe, ' from Moore where ',
                      input$firstAxe,  " like ('%') and ",
                      input$secondAxe, " like ('%') and ",
                      input$thirdAxe, " in ('",precAxeRes3(), "') order by " , input$fourthAxe,
                      sep='')            
      } 
      choicesValues = sqldf(query)
      output$query3 = renderPrint(paste("Fourth Query: ",query))
      selectInput(inputId = "fourthAxeOutput", label="", choices =  choicesValues[[1]], multiple = TRUE, selectize = FALSE) 
    }
  }
})
}
)
)

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这是一个来自反应式窗口小部件的动态查询示例。我希望这对某人有所帮助：

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不太清楚你在问什么。你只是想看看如何简化你的代码，还是你正在排除一个特定的错误？我要求简化我的代码，因为在我的实际应用中，我有12个研究轴，在我的例子中，我可以测试所有的可能性，因为我只有4个轴。正如您所看到的，我在代码中每次都重复查询，我想创建一个全局查询，并且每次用户选择一个axis==>global query+新的axis选项时，请不要发布可能损坏读取器工作区的代码。@G.Grothendieck，我的代码的损坏在哪里？这只是一个例子，您需要R、Shiny和sqldf包