R Shiny 如何在根据用户选择从 mysqlDB 检索数据时使用 renderPlot 构建条形图

Question

我在数据库中有一个数据集，根据用户的选择，我想在 r shiny 中使用渲染图构建一个条形图。我能够使用 renderTable 获取数据并将其显示为 table，但我无法创建 renderPlot。我也在尝试以数据帧的形式将数据从服务器获取到 UI，目前，我正在获取数据 Table.

P.S：这是我第一次学习R Shiny。只是想了解这种语言的动态。

这是我的代码。

library(DT)
library(shiny)
library(DBI)

# the user interface

ui <- fluidPage(

    titlePanel(strong ("Welcome to User Details")),
    sidebarPanel(

        selectInput("selectedName", label = h5("Select the User name here"),
                    choices = list("A", "B", "C", "D"),
                    selected = "A"),
        submitButton("Submit")
       
),
mainPanel(
    is.data.frame("data"),
    tableOutput("data")
 
)
)

# server
server <- function(input, output){
   
    output$data <- renderTable({
        conn <- dbConnect(
            drv = RMySQL::MySQL(),
            dbname = "mydb",
            host = "localhost",
            port = 3306,
            username = "root",
            password = "pwd")
        on.exit(dbDisconnect(conn), add = TRUE)
        dbGetQuery(conn, paste0(
            "Select name, age, gender from table1 Where userShortName = '", intput$selectedName, "';")
    })
}

# app launch
shinyApp(ui = ui, server = server)

并且输出将创建一个 False（对于数据框）并使用这 3 个列名名称、年龄、性别创建一个 Table。

我正在尝试通过对性别进行分组，根据姓名和年龄绘制一个简单的条形图。 X 轴上的姓名，Y 轴上的年龄，所有女性分组，所有男性分组在一起。

更新：

尝试使用 renderplot 而不是 renderTable

    library(DT)
    library(shiny)
    library(DBI)
    
    ui <- fluidPage(

    titlePanel(strong ("Welcome to User Details")),
    sidebarPanel(

        selectInput("selectedName", label = h5("Select the User name here"),
                    choices = list("A", "B", "C", "D"),
                    selected = "A"),
        submitButton("Submit")

),
    mainPanel(
        textOutput("sample_name"),
        plotOutput(outputId = "protein_data")
    ))
    
    # server
    server <- function(input, output){
       
        conn <- dbConnect(
            drv = RMySQL::MySQL(),
            dbname = "mydb",
            host = "localhost",
            port = 3306,
            username = "root",
            password = "pwd")
       
        output$data <- renderPlot({
           
           
            table <- dbGetQuery(conn, statement = "Select name, age, gender from table1 Where userShortName = '", intput$selectedName, "';")
           
            df <- as.data.frame(unclass(table(table$name,
                                               table$age)))
            
            barplot(x=table$name, y=table$age)
        })
    }
    
    # app launch
    shinyApp(ui = ui, server = server)

此代码出现以下错误：错误：需要闪亮的 finit xlim 值。

Answer 1

首先，您需要将图表呈现为 output$protein_data 而不是 output$data，因为它在您的第二个脚本中已不存在。

然后将条形图参数更改为 barplot(age~name, data = df)

library(DT)
library(shiny)
library(DBI)

ui <- fluidPage(
  
  titlePanel(strong ("Welcome to User Details")),
  sidebarPanel(
    
    selectInput("selectedName", label = h5("Select the User name here"),
                choices = list("A", "B", "C", "D"),
                selected = "A"),
    submitButton("Submit")
    
  ),
  mainPanel(
    textOutput("sample_name"),
    plotOutput(outputId = "protein_data")
  ))

# server
server <- function(input, output){
  
  conn <- dbConnect(
    drv = RMySQL::MySQL(),
    dbname = "mydb",
    host = "localhost",
    port = 3306,
    username = "root",
    password = "pwd")
  
  output$protein_data <- renderPlot({
    
    
    table <- dbGetQuery(conn, statement = "Select name, age, gender from table1 Where userShortName = '", intput$selectedName, "';")
    
    df <- as.data.frame(unclass(table(table$name,
                                      table$age)))
    
    barplot(age~name, data = df)
  })
}

# app launch
shinyApp(ui = ui, server = server)

Answer 2

将您的查询存储在 table 中并将该 table 转换为数据框。使用 renderplotly 和 plotly 方法绘制条形图。

library(DT)
library(shiny)
library(DBI)
library(plotly) # use plotly library here

# the user interface

ui <- fluidPage(

    titlePanel(strong ("Welcome to User Details")),
    sidebarPanel(

        selectInput("selectedName", label = h5("Select the User name here"),
                    choices = list("A", "B", "C", "D"),
                    selected = "A"),
        submitButton("Submit")       
),
mainPanel(
    is.data.frame("data"),
    tableOutput("data")
 
)
)

服务器

server <- function(input, output){
   
    output$data <- renderPlotly({

        conn <- dbConnect(
            drv = RMySQL::MySQL(),
            dbname = "mydb",
            host = "localhost",
            port = 3306,
            username = "root",
            password = "pwd")
        on.exit(dbDisconnect(conn), add = TRUE)
        table <- dbGetQuery(conn, paste0(
            "Select name, age, gender from table1 Where userShortName = '", input$selectedName, "';")
         
        # converting table into dataframes, easy to plot
        table1 <- as.data.frame(table)

        # Barplot using plotly
        plot_ly(data=table1,x=~name, y=~age, type="bar")%>%
            layout(
                title = "Title of Barplot",
                xaxis = list(title="Name"),
                yaxis = list(title="Age")
            )
    })
}

# app launch
shinyApp(ui = ui, server = server)

R Shiny 如何在根据用户选择从 mysqlDB 检索数据时使用 renderPlot 构建条形图

R Shiny How to use renderPlot to build barplot while retrieving data from mysqlDB based on user selection

mysql

r

rmysql

shiny

shiny-server

服务器