问题描述
大家好，
我计划在执行更新查询后（通过按下相应的按钮）使我的数据表自动更新。所以现在发生的是以下情况：
3。然后，用户将必须单击“导入数据”以刷新数据表。
我需要什么？
我打算省略用户再次单击导入数据以刷新数据表的需要。相反，只要单击按钮，数据表就会自动刷新。
此标签的UI部分：
# Extract data from server,edit and reupload
tabItem(
tabName="data_edit",fluidRow(
Box(width=2,background = "blue",h4("Step 1: Import sql data"),# Step 1: Import sql data
actionBttn(inputId = "import_button",label = "Import data",color = "primary",style = "material-flat"),br(),h4("Step 2: Make adjustment on main panel and choose status:"),actionBttn(inputId = "completed_button",label = "Completed",color = "success",actionBttn(inputId = "in_progress_button",label = "In Progress",color = "warning",actionBttn(inputId = "not_done_button",label = "Not Done",color = "danger",h4("Step 3: Click on 'IMPORT DATA' again to refresh!")
),DT::dataTableOutput({
"sql_file"
}),此部分的Server.R文件：
server <- function(input,output,session) {
observeEvent(input$import_button,{
pw <- {
"pw"
}
# loads the Postgresql driver
drv <- dbDriver("Postgresql")
# creates a connection to the postgres database
# note that "con" will be used later in each connection to the database
con <- dbConnect(drv,dbname = "test_db",host = "10.22.71.121",port = 5432,user = "user",password = pw)
#query the database and store the data in datafame
getQuery <- reactive({
sql_df <- dbGetQuery(con,"SELECT * from apple ;")
return(sql_df)
})
# Convert sql data to datatable
output$sql_file <- DT::renderDataTable({
DT::datatable(getQuery(),style = "default",filter = 'top',options = list(pageLength = 16,autoWidth = FALSE,scrollY = 650,scrollX = 500))
})
# Exporting changes to sql database
# Completed button
observeEvent(input$completed_button,{
s = getQuery()$row[input$sql_file_rows_selected]
# Change the "status" column in the dataframe as "Done"
for (i in s){
query <- sprintf("UPDATE public.apple SET status='completed' WHERE row = %s",i)
dbSendQuery(con,query)
cat("\nUpdated as completed for: ",i)
session$reload()
}
})
# In Progress button
observeEvent(input$in_progress_button,{
s = getQuery()$row[input$sql_file_rows_selected]
# Change the "Status" column in the dataframe as "Done"
for (i in s){
query <- sprintf("UPDATE public.apple SET status='in_progress' WHERE row = %s",query)
cat("\nUpdated as in progress for: ",i)
session$reload()
}
})
# Not done button
observeEvent(input$not_done_button,{
s = getQuery()$row[input$sql_file_rows_selected]
# Change the "Status" column in the dataframe as "Done"
for (i in s){
query <- sprintf("UPDATE public.apple SET status='not_done' WHERE row = %s",query)
cat("\nUpdated as not done for: ",i)
session$reload()
}
})
# disconnect the database after user exit the application. Best solution to resolve connection expire issue.
session$onSessionEnded(function(){
dbdisconnect(con)
})
})
}
解决方法
使用eventReactive应该可以满足您的需求。试试这个
server <- function(input,output,session) {
observeEvent(input$import_button,{
pw <- {
"pw"
}
# loads the PostgreSQL driver
drv <- dbDriver("PostgreSQL")
# creates a connection to the postgres database
# note that "con" will be used later in each connection to the database
con <- dbConnect(drv,dbname = "test_db",host = "10.22.71.121",port = 5432,user = "user",password = pw)
#query the database and store the data in datafame
getQuery <- reactive({
sql_df <- dbGetQuery(con,"SELECT * from apple ;")
return(sql_df)
})
DF1 <- reactiveValues(data=getQuery())
# Convert sql data to datatable
output$sql_file <- DT::renderDataTable({
DT::datatable(DF1$data,style = "default",filter = 'top',options = list(pageLength = 16,autoWidth = FALSE,scrollY = 650,scrollX = 500))
})
# Exporting changes to SQL database
# Completed button
observeEvent(input$completed_button,{
s = getQuery()$row[input$sql_file_rows_selected]
# Change the "status" column in the dataframe as "Done"
for (i in s){
query <- sprintf("UPDATE public.apple SET status='completed' WHERE row = %s",i)
dbSendQuery(con,query)
cat("\nUpdated as completed for: ",i)
session$reload()
}
})
DF1C <- eventReactive(input$completed_button,{
sql_dfc <- dbGetQuery(con,"SELECT * from apple ;")
return(sql_dfc)
})
DF1$data <- DF1C
# In Progress button
observeEvent(input$in_progress_button,{
s = getQuery()$row[input$sql_file_rows_selected]
# Change the "Status" column in the dataframe as "Done"
for (i in s){
query <- sprintf("UPDATE public.apple SET status='in_progress' WHERE row = %s",query)
cat("\nUpdated as in progress for: ",i)
session$reload()
}
})
DF1P <- eventReactive(input$in_progress_button,{
sql_dfp <- dbGetQuery(con,"SELECT * from apple ;")
return(sql_dfp)
})
DF1$data <- DF1P
# Not done button
observeEvent(input$not_done_button,{
s = getQuery()$row[input$sql_file_rows_selected]
# Change the "Status" column in the dataframe as "Done"
for (i in s){
query <- sprintf("UPDATE public.apple SET status='not_done' WHERE row = %s",query)
cat("\nUpdated as not done for: ",i)
session$reload()
}
})
DF1ND <- eventReactive(input$not_done_button,{
sql_dfnd <- dbGetQuery(con,"SELECT * from apple ;")
return(sql_dfnd)
})
DF1$data <- DF1ND
# Disconnect the database after user exit the application. Best solution to resolve connection expire issue.
session$onSessionEnded(function(){
dbDisconnect(con)
})
})
}