Sample SQLite database app

db-example.go

package main

import (
	"database/sql"
	"fmt"

	_ "github.com/mattn/go-sqlite3"
)

func main() {
	//1. Open connection

	db, err := sql.Open("sqlite3", ":memory:")
	checkErr(err)
	defer db.Close()

	//2. fail-fast if can't connect to DB

	checkErr(db.Ping())

	//3. create table

	_, err = db.Exec("create table USER (ID integer PRIMARY KEY, NAME string not null); delete from USER;")
	checkErr(err)

	//4. insert data

	//4.1 Begin transaction
	tx, err := db.Begin()
	checkErr(err)

	//4.2 Prepare insert stmt.
	stmt, err := tx.Prepare("insert into USER(ID, NAME) values(?, ?)")
	checkErr(err)
	defer stmt.Close()

	for i := 0; i < 10; i++ {
		_, err = stmt.Exec(i, fmt.Sprint("user-", i))
		checkErr(err)
	}

	//4.3 Commit transaction
	tx.Commit()

	//5. Query data

	rows, err := db.Query("select * from USER")
	checkErr(err)
	defer rows.Close()

	//5.1 Iterate through result set
	for rows.Next() {
		var name string
		var id int
		err := rows.Scan(&id, &name)
		checkErr(err)
		fmt.Printf("id=%d, name=%s\n", id, name)
	}

	//5.2 check error, if any, that were encountered during iteration
	err = rows.Err()
	checkErr(err)
}

func checkErr(err error, args ...string) {
	if err != nil {
		fmt.Println("Error")
		fmt.Println("%q: %s", err, args)
	}
}