Refactor store: use migrations and split logic

internal/store/cake.go

@@ -0,0 +1,65 @@
+package store
+
+import (
+	"errors"
+	"strconv"
+)
+
+type Cake struct {
+	Name   string
+	ID     int
+	Price  int
+	Amount int
+}
+
+
+func (s *Store) GetCake(id int) (Cake, error) {
+	out := Cake{ID: id}
+	row, err := s.db.Query("select name, price from cake where id = ?;", id)
+	if err != nil {
+		return out, err
+	}
+	defer row.Close()
+	row.Next()
+	err = row.Scan(&out.Name, &out.Price)
+	return out, err
+}
+
+func (s *Store) GetCakes() ([]Cake, error) {
+	rows, err := s.db.Query("select id, name, price from cake")
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	cakes := make([]Cake, 0)
+	for rows.Next() {
+		var c Cake
+		c.Amount = 0
+		err = rows.Scan(&c.ID, &c.Name, &c.Price)
+		if err != nil {
+			return nil, err
+		}
+		cakes = append(cakes, c)
+	}
+	return cakes, err
+}
+
+func (s *Store) SaveCake(newCake Cake) (int, error) {
+	query := "insert into cake(name, price) values (?, ?) returning id;"
+	if newCake.ID != 0 {
+		query = "update cake set name = ? , price = ? where id = "
+		query += strconv.Itoa(newCake.ID) + " returning id;"
+	}
+
+	row, err := s.db.Query(query, newCake.Name, newCake.Price)
+	if err != nil {
+		return 0, err
+	}
+	defer row.Close()
+
+	if !row.Next() {
+		return 0, errors.New("The database didn't respond with an id")
+	}
+	err = row.Scan(&newCake.ID)
+	return newCake.ID, err
+}