example for parsing a file & inserting into a database, using golang

app.go

package main

import (
	// "flag"
	"fmt"
	"os"
	"strings"
	"strconv"
	"database/sql"
	"compress/gzip"
	"io"
	// "io/ioutil"
	"bufio"
)
import _ "github.com/go-sql-driver/mysql"

func process(db *sql.DB, ioReader io.Reader) {
	cmd, err := db.Prepare("insert into table (...) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)")
	if err != nil { panic(err) }

	scanner := bufio.NewScanner(ioReader)
	scanner.Scan() // first line is header

	for scanner.Scan() {
		parts := strings.Split(scanner.Text(), "|")
		tac, _ := strconv.Atoi(parts[0])
		_, err := cmd.Exec(tac, parts[1], parts[2], parts[3], parts[4], parts[5], parts[6], parts[7], parts[8], parts[9], parts[10], parts[11], parts[12], parts[13], parts[14], parts[15], parts[16])
		if err != nil { fmt.Println(err) }
	}
}

func main() {
	if len(os.Args) < 2 {
		fmt.Println("must provide path to data file")
		return
	}

	path := os.Args[1]
	reader, err := os.Open(path)
	defer reader.Close()
	if err != nil { panic(err) }

	fmt.Println("(re)creating database tables")
	db, err := sql.Open("mysql", ":@unix(/opt/local/var/run/mariadb/mysqld.sock)/table?parseTime=true") 
	// db, err := sql.Open("mysql", ":@192.168.2.107/table")
	defer db.Close()
	if err != nil { panic(err) }

	// sql, _ := ioutil.ReadFile("db.sql")
	// db.Exec(string(sql))
	db.Exec("delete from table")

	fmt.Println("processing file")
	if !strings.HasSuffix(path, ".gz") {
		process(db, reader)
	} else {
		gzReader, _ := gzip.NewReader(reader)
		defer gzReader.Close()
		fmt.Println(" --> decompressing gzip")
		process(db, gzReader)
	}
}