Shiny-R PostgresSQL Example

doc/apps/shiny-r.md

@@ -150,10 +150,14 @@ If you need help installing certain libraries, email us at [[email protected]]
 :link: https://github.com/ploomber/doc/tree/main/examples/shiny-r/docker-based
 :::
 
-:::{grid-item-card} Data visualization
+:::{grid-item-card} Data Visualization
 :link: https://github.com/ploomber/doc/tree/main/examples/shiny-r/shiny-r-data-visualization
 ![](https://github.com/ploomber/doc/raw/main/examples/shiny-r/shiny-r-data-visualization/screenshot.webp)
 :::
 
+:::{grid-item-card} App Connected to Postgres
+:link: https://github.com/ploomber/doc/tree/main/examples/shiny-r/connect-shiny-to-postgresql
+![](https://github.com/ploomber/doc/tree/main/examples/shiny-r/connect-shiny-to-postgresql/screenshot.png)
+:::
 
 ::::

examples/shiny-r/connect-shiny-to-postgresql/Dockerfile

@@ -0,0 +1,14 @@
+FROM rocker/shiny
+
+WORKDIR /app
+
+RUN apt-get update 
+RUN apt-get install -y libpq-dev
+
+COPY install.R /app/
+
+RUN Rscript install.R
+
+COPY . /app
+
+ENTRYPOINT ["Rscript", "startApp.R"]

examples/shiny-r/connect-shiny-to-postgresql/README.md

@@ -0,0 +1,10 @@
+# R Shiny App Connected to PostgreSQL Database
+
+Interactive R Shiny dashboard, connected to PostgreSQL database.
+
+![](screenshot.png)
+
+To use the app, fill in the database parameters with the parameters from your PostgreSQL database. 
+
+NOTE: The data used in this app is not present in this repository, to obtain the data, go to this [link](https://archive.ics.uci.edu/dataset/320/student+performance), download and unzip the data folder. 
+

examples/shiny-r/connect-shiny-to-postgresql/app.R

@@ -0,0 +1,93 @@
+library(shiny)
+library(DBI)
+library(bslib)
+library(dplyr)
+library(ggplot2
+db <- "[DATABASE NAME]"
+db_host <- "[YOUR HOST ADDRESS]"
+db_port <- "[PORT NUMBER]"
+db_user <- "[DATABASE USERNAME]"
+db_pass <- "[DATABASE PASSWORD]"
+
+conn <- dbConnect(
+  RPostgres::Postgres(),
+  dbname = db,
+  host = db_host,
+  port = db_port,
+  user = db_user,
+  password = db_pass
+)
+
+tables <- dbListTables(conn)
+
+ui <- page_sidebar(
+  title = "PostgreSQL with R Shiny Demo",
+
+  sidebar = sidebar(
+    accordion(
+      accordion_panel(
+        "Main Controls",
+        selectInput(inputId = "table",
+          label = "Select Table in Database",
+          choices = tables,
+          selected = tables[]),
+          accordion_panel(
+            "Histogram Controls",
+            selectInput(inputId = "hist_x",
+              label = "Variable",
+              choices = NULL)
+          ),
+          accordion_panel(
+            "Scatterplot Controls",
+            selectInput(inputId = "scatter_x",
+              label = "X Variable",
+              choices = NULL),
+            selectInput(inputId = "scatter_y",
+              label = "Y Variable",
+              choices = NULL)
+          )
+      )
+    )
+  ),
+  plotOutput(outputId = "hist"),
+  plotOutput(outputId = "scatter")
+)
+
+server <- function(input, output, session) {
+
+  quant_vars <- reactive({
+    query <- sprintf("SELECT * FROM %s LIMIT 1", input$table)
+    df <- dbGetQuery(conn, query)
+    names(dplyr::select_if(df, is.numeric))
+  })
+
+  observe({
+    updateSelectInput(session, "hist_x", choices = quant_vars())
+    updateSelectInput(session, "scatter_x", choices = quant_vars())
+    updateSelectInput(session, "scatter_y", choices = quant_vars())
+  })
+
+  output$hist <- renderPlot({
+    query <- sprintf("SELECT * FROM %s", input$table)
+    df <- dbGetQuery(conn, query)
+
+    ggplot(df, aes_string(x = input$hist_x)) + 
+      geom_histogram(fill = "turquoise") +
+      labs(title = sprintf("Distribution of %s", input$hist_x), 
+            x = input$hist_x,
+            y = "Frequency")
+  })
+
+  output$scatter <- renderPlot({
+    query <- sprintf("SELECT * FROM %s", input$table)
+    df <- dbGetQuery(conn, query)
+
+    ggplot(df, aes_string(x = input$scatter_x, y = input$scatter_y)) + 
+      geom_point(alpha = 0.5) + 
+      labs(title = sprintf("%s vs %s", input$scatter_y, input$scatter_x),
+            x = input$scatter_x,
+            y = input$scatter_y)
+  })
+}
+
+shinyApp(ui = ui, server = server)

examples/shiny-r/connect-shiny-to-postgresql/install.R

@@ -0,0 +1,6 @@
+install.packages("shiny")
+install.packages("RPostgres")
+install.packages("DBI")
+install.packages("bslib")
+install.packages("dplyr")
+install.packages("ggplot2")

examples/shiny-r/connect-shiny-to-postgresql/startApp.R

@@ -0,0 +1,4 @@
+library(shiny)
+options(shiny.host = '0.0.0.0')
+options(shiny.port = 80)
+runApp('app.R')

examples/shiny-r/connect-shiny-to-postgresql/upload.R

@@ -0,0 +1,26 @@
+library(DBI)
+
+db <- "[DATABASE NAME]"
+db_host <- "[YOUR HOST ADDRESS]"
+db_port <- "[PORT NUMBER]" 
+db_user <- "[DATABASE USERNAME]"
+db_pass <- "[DATABASE PASSWORD]"
+
+conn <- dbConnect(
+  RPostgres::Postgres(),
+  dbname = db,
+  host = db_host,
+  port = db_port,
+  user = db_user,
+  password = db_pass
+)
+
+math <- read.csv("data/student-mat.csv", sep=';')
+por <- read.csv("data/student-por.csv", sep=';')
+
+print(conn)
+
+dbWriteTable(conn, "math", math, overwrite=TRUE)
+dbWriteTable(conn, "portuguese", por, overwrite=TRUE)
+
+dbDisconnect(conn)