Files
build-web-application-with-…/de/code/src/apps/ch.5.4/main.go
2017-05-30 11:22:13 +08:00

79 lines
1.7 KiB
Go

// Example code for Chapter 5.4 from "Build Web Application with Golang"
// Purpose: Show how to perform CRUD operations using a postgres driver
package main
import (
"database/sql"
"fmt"
"time"
_ "github.com/lib/pq"
)
const (
DB_USER = "user"
DB_PASSWORD = ""
DB_NAME = "test"
)
func main() {
dbinfo := fmt.Sprintf("user=%s password=%s dbname=%s sslmode=disable",
DB_USER, DB_PASSWORD, DB_NAME)
db, err := sql.Open("postgres", dbinfo)
checkErr(err)
defer db.Close()
fmt.Println("# Inserting values")
var lastInsertId int
err = db.QueryRow("INSERT INTO userinfo(username,departname,created) VALUES($1,$2,$3) returning uid;",
"astaxie", "software developement", "2012-12-09").Scan(&lastInsertId)
checkErr(err)
fmt.Println("id of last inserted row =", lastInsertId)
fmt.Println("# Updating")
stmt, err := db.Prepare("update userinfo set username=$1 where uid=$2")
checkErr(err)
res, err := stmt.Exec("astaxieupdate", lastInsertId)
checkErr(err)
affect, err := res.RowsAffected()
checkErr(err)
fmt.Println(affect, "row(s) changed")
fmt.Println("# Querying")
rows, err := db.Query("SELECT * FROM userinfo")
checkErr(err)
for rows.Next() {
var uid int
var username string
var department string
var created time.Time
err = rows.Scan(&uid, &username, &department, &created)
checkErr(err)
fmt.Println("uid | username | department | created ")
fmt.Printf("%3v | %8v | %6v | %6v\n", uid, username, department, created)
}
fmt.Println("# Deleting")
stmt, err = db.Prepare("delete from userinfo where uid=$1")
checkErr(err)
res, err = stmt.Exec(lastInsertId)
checkErr(err)
affect, err = res.RowsAffected()
checkErr(err)
fmt.Println(affect, "row(s) changed")
}
func checkErr(err error) {
if err != nil {
panic(err)
}
}