inftech/cmd/importTeilnehmer/main.go
2017-03-08 20:15:10 +01:00

112 lines
2.2 KiB
Go

package main
import (
"database/sql"
"encoding/csv"
"flag"
"log"
"os"
"strconv"
_ "github.com/go-sql-driver/mysql"
)
// Student from Database
type Student struct {
Vorname, Nachname string
Matrikelnummer int
StudiengangID int
}
var (
databaseURL = flag.String("db", "julian:hi@/test", "The Database url")
)
const (
insertQuery = "INSERT INTO Teilnehmer (Nachname, Vorname, Matrnr, Studiengang) VALUES(?,?,?,?)"
)
// Main Function
func main() {
flag.Parse()
if flag.NArg() == 0 {
log.Fatal("no file(s) given!")
}
// try to open file
file, err := os.Open(flag.Arg(0))
if err != nil {
log.Fatal("could not open file:", err)
}
defer file.Close()
reader := csv.NewReader(file)
defer log.Println("shutdown completed")
// list all Database providers
log.Println("Database providers:", sql.Drivers())
// connect to database
db, err := sql.Open("mysql", *databaseURL)
if err != nil {
log.Fatal(err)
}
defer db.Close()
log.Println("mysql connection established")
// prepare Queries
newStudent, err := db.Prepare(insertQuery)
if err != nil {
log.Fatal("Error preparing statement:", insertQuery+":", err)
}
defer newStudent.Close()
// init completed
defer log.Println("shutting down")
var (
line []string
linenumber = 0
count = 0
)
for ; err == nil; line, err = reader.Read() {
linenumber++
if len(line) < 4 {
log.Println("line", linenumber, "malformed")
continue
}
number, err := strconv.Atoi(line[2])
if err != nil {
log.Println("line", linenumber, ":could not convert ID:"+line[2]+":", err)
continue
}
if number < 0 {
log.Println("line", linenumber, ":ID invalid:", number)
continue
}
studiengang, err := strconv.Atoi(line[3])
if err != nil {
log.Println("line", linenumber, ":studiengang could not be converted:", err)
continue
}
if studiengang < 0 || studiengang > 2 {
log.Println("line", linenumber, ":Studiengang does not exist:", studiengang)
continue
}
if _, err := newStudent.Exec(line[0], line[1], number, studiengang); err != nil {
log.Println("line", linenumber, ":could not execute INSERT:", err)
continue
}
count++
}
log.Println("done, inserted", count, "records")
}