Nir Nir - 8 months ago 35
SQL Question

Go Postgres driver: Error when add a query parameter

I'm new to

go
and currently just play a little.

When I write the code:

err := database.QueryRow("SELECT page_title,page_content,page_date FROM pages WHERE id=1").Scan(&thisPage.Title, &thisPage.Content, &thisPage.Date)


Everything works fine. But I want it to not just get the page with
id=1
, but to be dynamic.

So I write:

err := database.QueryRow("SELECT page_title,page_content,page_date FROM pages WHERE id=?", pageID).Scan(&thisPage.Title, &thisPage.Content, &thisPage.Date)


But I get an error:

enter image description here

The full code:

package main

import (
"database/sql"
"fmt"
_ "github.com/lib/pq"
"github.com/gorilla/mux"
"log"
"net/http"
)

const (
DBHost = "localhost"
DBPort = ":5432"
DBUser = "nirgalon"
DBPass = ""
DBDbase = "cms"
PORT = ":8080"
)

var database *sql.DB

type Page struct {
Title string
Content string
Date string
}

func ServePage(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
pageID := vars["id"]
thisPage := Page{}
fmt.Println(pageID)
err := database.QueryRow("SELECT page_title,page_content,page_date FROM pages WHERE id=1").Scan(&thisPage.Title, &thisPage.Content, &thisPage.Date)
if err != nil {
log.Fatal("Couldn't get page: " + pageID)
log.Fatal(err.Error)
}
html := `<html><head><title>` + thisPage.Title + `</title></head><body><h1>` + thisPage.Title + `</h1><div>` + thisPage.Content + `</div></body></html>`
fmt.Fprintln(w, html)
}

func main() {
db, err := sql.Open("postgres", "user=nirgalon dbname=cms sslmode=disable")
if err != nil {
log.Println("Couldn't connnect to db")
log.Fatal(err)
}
database = db

routes := mux.NewRouter()
routes.HandleFunc("/page/{id:[0-9]+}", ServePage)
http.Handle("/", routes)
http.ListenAndServe(PORT, nil)
}

Answer Source

psql driver uses $1, $2, etc for params:

database.QueryRow("SELECT page_title,page_content,page_date FROM pages WHERE id = $1", pageID)