R Shinny:在Shinny应用程序中的反应式RMySQL查询中未找到表对象
[编辑]:agstudy的解决方案对我有效。 我有一个闪亮的应用程序,允许用户在MySQL数据库的三个表之间切换。用户可以选择Renderable用于生成对象的表 我将if语句放在renderable中,以响应用户选择的表 当我运行应用程序时,任何表格都无法打印,无法查看 服务器.RR Shinny:在Shinny应用程序中的反应式RMySQL查询中未找到表对象,mysql,r,shiny,Mysql,R,Shiny,[编辑]:agstudy的解决方案对我有效。 我有一个闪亮的应用程序,允许用户在MySQL数据库的三个表之间切换。用户可以选择Renderable用于生成对象的表 我将if语句放在renderable中,以响应用户选择的表 当我运行应用程序时,任何表格都无法打印,无法查看 服务器.R library(shiny) library(RMySQL) con <- dbConnect(RMySQL::MySQL(),user="x",password="x",host="dbhost",dbn
library(shiny)
library(RMySQL)
con <- dbConnect(RMySQL::MySQL(),user="x",password="x",host="dbhost",dbname="db")
shinyServer(function(input, output) {
data <- reactive({
selectInput("input$data", "Choose your Input:", choices = c('data1'='1','data2'='2', 'data3'='3'))
})
output$table <- renderTable({
if(input$data == data1){
query1 <- reactive({ "SELECT *
FROM data1
ORDER BY var1, var2"})
reactive({dbGetQuery(con,query1())})
head(data())
} else if(input$data == data2){
query1 <- reactive({ "SELECT *
FROM data2
ORDER BY var1, var2"})
reactive({dbGetQuery(con,query1())})
head(data())
} else if(input$data == data3){
query1 <- reactive({ "SELECT *
FROM data3
ORDER BY var1, var2"})
reactive({dbGetQuery(con,query1())})
head(data())
} else print("Select a dataset")
})
})
这里的问题在任何情况下都与MySQLserver无关,但存在一个无UI逻辑。如果不隔离代码部分,在
shinny
中编程并不容易:
- 输入:在ui界面中定义
- 反应式功能:应在每次更改输入时更改
- 输出:一旦输入数据被被动功能更改,将刷新输出
library(RMySQL)
library(shiny)
## this a public function that will be used
## in the server side to connect to the data base
## and retrieve data
get_data <-
function(query){
on.exit(dbDisconnect(conn)) ## important to close connection
conn <- dbConnect("MySQL",user="xuser",
password="xpws",
host="xhost",
dbname="xdbname")
dbGetQuery(con,query)
}
server <- shinyServer(
function(input, output) {
## the reactive engine that will refresh query
## each time input changed
query <- reactive( sprintf("SELECT *
FROM %s
ORDER BY var1, var2",input$data)
)
## simply displaying reactive inputs
output$table <- renderTable(
if(input$data!="") get_data(query())
)
})
## define ui elements by step
## for easy indenting
ui_panel <-
tabPanel("Test",
sidebarLayout(
sidebarPanel(
selectInput("data", label = "Data set",
choices = c("","data1", "data2", "data3"))
),
mainPanel(
tableOutput("table")
)
)
)
ui <- shinyUI(navbarPage("Test",ui_panel))
runApp(list(ui=ui,server=server))
库(RMySQL)
图书馆(闪亮)
##这是一个将要使用的公共函数
##在服务器端连接到数据库
##并检索数据
获取数据谢谢您的快速回复。这个解决方案对我有效。
library(RMySQL)
library(shiny)
## this a public function that will be used
## in the server side to connect to the data base
## and retrieve data
get_data <-
function(query){
on.exit(dbDisconnect(conn)) ## important to close connection
conn <- dbConnect("MySQL",user="xuser",
password="xpws",
host="xhost",
dbname="xdbname")
dbGetQuery(con,query)
}
server <- shinyServer(
function(input, output) {
## the reactive engine that will refresh query
## each time input changed
query <- reactive( sprintf("SELECT *
FROM %s
ORDER BY var1, var2",input$data)
)
## simply displaying reactive inputs
output$table <- renderTable(
if(input$data!="") get_data(query())
)
})
## define ui elements by step
## for easy indenting
ui_panel <-
tabPanel("Test",
sidebarLayout(
sidebarPanel(
selectInput("data", label = "Data set",
choices = c("","data1", "data2", "data3"))
),
mainPanel(
tableOutput("table")
)
)
)
ui <- shinyUI(navbarPage("Test",ui_panel))
runApp(list(ui=ui,server=server))