new exporter version

testing/go-code-samples/go-db-comparison/examples/database-sql/database-sql.go

@@ -0,0 +1,123 @@
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"log"
+	"time"
+
+	_ "github.com/go-sql-driver/mysql"
+)
+
+type Student struct {
+	ID          int
+	Fname       string
+	Lname       string
+	DateOfBirth time.Time
+	Email       string
+	Address     string
+	Gender      string
+}
+
+var db *sql.DB
+
+func main() {
+	var err error
+	db, err = dbSqlConnect()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	s := Student{
+		Fname:       "Leon",
+		Lname:       "Ashling",
+		DateOfBirth: time.Date(1994, time.August, 14, 23, 51, 42, 0, time.UTC),
+		Email:       "lashling5@senate.gov",
+		Address:     "39 Kipling Pass",
+		Gender:      "Male",
+	}
+
+	//adding student record to table
+	sID, err := addStudent(s)
+	if err != nil {
+		fmt.Println(err)
+	}
+	fmt.Printf("addSudent id: %v \n", sID)
+
+	//selecting student by ID
+	st, err := studentByID(sID)
+	if err != nil {
+		fmt.Println(err)
+	}
+	fmt.Printf("studentByID id: %v \n", st)
+
+	students, err := fetchStudents()
+	if err != nil {
+		fmt.Println(err)
+	}
+
+	fmt.Printf("fetchStudents count: %v \n", len(students))
+}
+
+func dbSqlConnect() (*sql.DB, error) {
+	// Opening a database connection.
+	db, err := sql.Open("mysql", "theuser:thepass@tcp(localhost:3306)/thedb?parseTime=true")
+	if err != nil {
+		return nil, err
+	}
+	fmt.Println("Connected!")
+	return db, nil
+}
+
+func addStudent(s Student) (int64, error) {
+	query := "insert into students (fname, lname, date_of_birth, email, gender, address) values (?, ?, ?, ?, ?, ?);"
+	result, err := db.Exec(query, s.Fname, s.Lname, s.DateOfBirth, s.Email, s.Gender, s.Address)
+	if err != nil {
+		return 0, fmt.Errorf("addStudent Error: %v", err)
+	}
+
+	id, err := result.LastInsertId()
+	if err != nil {
+		return 0, fmt.Errorf("addSudent Error: %v", err)
+	}
+
+	return id, nil
+}
+
+func fetchStudents() ([]Student, error) {
+	// A slice of Students to hold data from returned rows.
+	var students []Student
+
+	rows, err := db.Query("SELECT * FROM students")
+	if err != nil {
+		return nil, fmt.Errorf("fetchStudents %v", err)
+	}
+	defer rows.Close()
+
+	// Loop through rows, using Scan to assign column data to struct fields.
+	for rows.Next() {
+		var s Student
+		if err := rows.Scan(&s.ID, &s.Fname, &s.Lname, &s.DateOfBirth, &s.Email, &s.Address, &s.Gender); err != nil {
+			return nil, fmt.Errorf("fetchStudents %v", err)
+		}
+		students = append(students, s)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("fetchStudents %v", err)
+	}
+
+	return students, nil
+}
+
+func studentByID(id int64) (Student, error) {
+	var st Student
+
+	row := db.QueryRow("SELECT * FROM students WHERE id = ?", id)
+	if err := row.Scan(&st.ID, &st.Fname, &st.Lname, &st.DateOfBirth, &st.Email, &st.Address, &st.Gender); err != nil {
+		if err == sql.ErrNoRows {
+			return st, fmt.Errorf("studentById %d: no such student", id)
+		}
+		return st, fmt.Errorf("studentById %d: %v", id, err)
+	}
+	return st, nil
+}