initial commit

cmd/importPunkte/main.go

@@ -0,0 +1,141 @@
+package main
+
+import (
+	"bufio"
+	"database/sql"
+	"encoding/csv"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+
+	_ "github.com/go-sql-driver/mysql"
+)
+
+var (
+	dbURL = flag.String("db", "julian:hi@/test", "The Database")
+)
+
+const (
+	queryInsert = "INSERT INTO Punkte (Matrnr, Aufgabe, Punkte) VALUES(?,?,?)"
+)
+
+// This function  assumes it input to be only one float
+func convertFloat(input string) string {
+	// replace all , with .
+	return strings.Replace(input, ",", ".", -1)
+}
+
+func YesNo() bool {
+	reader := bufio.NewReader(os.Stdin)
+	for {
+		line, _, err := reader.ReadLine()
+		if err != nil {
+			return false
+		}
+
+		// default case
+		if len(line) == 0 {
+			return true
+		}
+
+		switch line[0] {
+		case 'Y':
+			fallthrough
+		case 'y':
+			return true
+		case 'N':
+			fallthrough
+		case 'n':
+			return false
+		}
+	}
+}
+
+func main() {
+	flag.Parse()
+
+	files := flag.Args()
+	if len(files) == 0 {
+		log.Fatal("no files given!")
+	}
+
+	db, err := sql.Open("mysql", *dbURL)
+	if err != nil {
+		log.Fatal("error connecting to Database:", err)
+	}
+	defer db.Close()
+
+	for _, f := range files {
+		log.Println("importing", f)
+		file, err := os.Open(f)
+		if err != nil {
+			log.Println("could not open file:", f+":", err)
+			continue
+		}
+
+		reader := csv.NewReader(file)
+		transaction, err := db.Begin()
+		if err != nil {
+			log.Fatal("cannot prepare statement:", err)
+		}
+
+		stmt, err := transaction.Prepare(queryInsert)
+		if err != nil {
+			log.Fatal("could not prepare insert statement:", err)
+		}
+		defer stmt.Close()
+
+		var (
+			line      []string
+			count     = 0
+			linecount = 0
+
+			ID      int
+			Aufgabe = 1
+			points  float64
+		)
+
+		for {
+			linecount++
+			line, err = reader.Read()
+			if err != nil || line == nil {
+				break
+			}
+
+			if len(line) < 2 {
+				log.Println(linecount, ": malformed line")
+				continue
+			}
+
+			if ID, err = strconv.Atoi(line[0]); err != nil {
+				log.Println(linecount, ": no ID given, could not convert:", err)
+				continue
+			}
+
+			fmt.Print(ID, " ")
+
+			Aufgabe = 1
+			for _, p := range line[1:] {
+				if points, err = strconv.ParseFloat(convertFloat(p), 32); err != nil {
+					log.Println(linecount, "A", Aufgabe, ": could not parse points:", err)
+				}
+				fmt.Print(points, " ")
+
+				if _, err = stmt.Exec(ID, Aufgabe, points); err != nil {
+					log.Println(linecount, ": error inserting:", err)
+				}
+				Aufgabe++
+			}
+			fmt.Println()
+			count++
+		}
+		fmt.Println("read", count, "Students")
+		fmt.Println("commit changes? (Y/n)")
+		if YesNo() {
+			transaction.Commit()
+		}
+	}
+}