reorganization of _examples and add some new examples such as iris+groupcache+mysql+docker

Former-commit-id: ed635ee95de7160cde11eaabc0c1dcb0e460a620

_examples/database/mysql/service/category_service.go

@@ -0,0 +1,74 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+
+	"myapp/entity"
+	"myapp/sql"
+)
+
+// CategoryService represents the category entity service.
+// Note that the given entity (request) should be already validated
+// before service's calls.
+type CategoryService struct {
+	*sql.Service
+}
+
+// NewCategoryService returns a new category service to communicate with the database.
+func NewCategoryService(db sql.Database) *CategoryService {
+	return &CategoryService{Service: sql.NewService(db, new(entity.Category))}
+}
+
+// Insert stores a category to the database and returns its ID.
+func (s *CategoryService) Insert(ctx context.Context, e entity.Category) (int64, error) {
+	if e.Title == "" || e.ImageURL == "" {
+		return 0, sql.ErrUnprocessable
+	}
+
+	q := fmt.Sprintf(`INSERT INTO %s (title, position, image_url)
+	VALUES (?,?,?);`, e.TableName())
+
+	res, err := s.DB().Exec(ctx, q, e.Title, e.Position, e.ImageURL)
+	if err != nil {
+		return 0, err
+	}
+
+	return res.LastInsertId()
+}
+
+// Update updates a category based on its `ID`.
+func (s *CategoryService) Update(ctx context.Context, e entity.Category) (int, error) {
+	if e.ID == 0 || e.Title == "" || e.ImageURL == "" {
+		return 0, sql.ErrUnprocessable
+	}
+
+	q := fmt.Sprintf(`UPDATE %s
+    SET
+	    title = ?,
+	    position = ?,
+	    image_url = ?
+	WHERE %s = ?;`, e.TableName(), e.PrimaryKey())
+
+	res, err := s.DB().Exec(ctx, q, e.Title, e.Position, e.ImageURL, e.ID)
+	if err != nil {
+		return 0, err
+	}
+
+	n := sql.GetAffectedRows(res)
+	return n, nil
+}
+
+// The updatable fields, separately from that we create for any possible future necessities.
+var categoryUpdateSchema = map[string]reflect.Kind{
+	"title":     reflect.String,
+	"image_url": reflect.String,
+	"position":  reflect.Int,
+}
+
+// PartialUpdate accepts a key-value map to
+// update the record based on the given "id".
+func (s *CategoryService) PartialUpdate(ctx context.Context, id int64, attrs map[string]interface{}) (int, error) {
+	return s.Service.PartialUpdate(ctx, id, categoryUpdateSchema, attrs)
+}

_examples/database/mysql/service/category_service_test.go

@@ -0,0 +1,42 @@
+package service
+
+import (
+	"context"
+	"testing"
+
+	"myapp/entity"
+	"myapp/sql"
+
+	"github.com/DATA-DOG/go-sqlmock"
+)
+
+func TestCategoryServiceInsert(t *testing.T) {
+	conn, mock, err := sqlmock.New(sqlmock.QueryMatcherOption(sqlmock.QueryMatcherEqual))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+
+	db := &sql.MySQL{Conn: conn}
+	service := NewCategoryService(db)
+	newCategory := entity.Category{
+		Title:    "computer-internet",
+		Position: 2,
+		ImageURL: "https://animage",
+	}
+	mock.ExpectExec("INSERT INTO categories (title, position, image_url) VALUES (?,?,?);").
+		WithArgs(newCategory.Title, newCategory.Position, newCategory.ImageURL).WillReturnResult(sqlmock.NewResult(1, 1))
+
+	id, err := service.Insert(context.TODO(), newCategory)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if id != 1 {
+		t.Fatalf("expected ID to be 1 as this is the first entry")
+	}
+
+	if err = mock.ExpectationsWereMet(); err != nil {
+		t.Fatal(err)
+	}
+}

_examples/database/mysql/service/product_service.go

@@ -0,0 +1,110 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+	"strings"
+
+	"myapp/entity"
+	"myapp/sql"
+)
+
+// ProductService represents the product entity service.
+// Note that the given entity (request) should be already validated
+// before service's calls.
+type ProductService struct {
+	*sql.Service
+	rec sql.Record
+}
+
+// NewProductService returns a new product service to communicate with the database.
+func NewProductService(db sql.Database) *ProductService {
+	return &ProductService{Service: sql.NewService(db, new(entity.Product))}
+}
+
+// Insert stores a product to the database and returns its ID.
+func (s *ProductService) Insert(ctx context.Context, e entity.Product) (int64, error) {
+	if !e.ValidateInsert() {
+		return 0, sql.ErrUnprocessable
+	}
+
+	q := fmt.Sprintf(`INSERT INTO %s (category_id, title, image_url, price, description)
+	VALUES (?,?,?,?,?);`, e.TableName())
+
+	res, err := s.DB().Exec(ctx, q, e.CategoryID, e.Title, e.ImageURL, e.Price, e.Description)
+	if err != nil {
+		return 0, err
+	}
+
+	return res.LastInsertId()
+}
+
+// BatchInsert inserts one or more products at once and returns the total length created.
+func (s *ProductService) BatchInsert(ctx context.Context, products []entity.Product) (int, error) {
+	if len(products) == 0 {
+		return 0, nil
+	}
+
+	var (
+		valuesLines []string
+		args        []interface{}
+	)
+
+	for _, p := range products {
+		if !p.ValidateInsert() {
+			// all products should be "valid", we don't skip, we cancel.
+			return 0, sql.ErrUnprocessable
+		}
+
+		valuesLines = append(valuesLines, "(?,?,?,?,?)")
+		args = append(args, []interface{}{p.CategoryID, p.Title, p.ImageURL, p.Price, p.Description}...)
+	}
+
+	q := fmt.Sprintf("INSERT INTO %s (category_id, title, image_url, price, description) VALUES %s;",
+		s.RecordInfo().TableName(),
+		strings.Join(valuesLines, ", "))
+
+	res, err := s.DB().Exec(ctx, q, args...)
+	if err != nil {
+		return 0, err
+	}
+
+	n := sql.GetAffectedRows(res)
+	return n, nil
+}
+
+// Update updates a product based on its `ID` from the database
+// and returns the affected numbrer (0 when nothing changed otherwise 1).
+func (s *ProductService) Update(ctx context.Context, e entity.Product) (int, error) {
+	q := fmt.Sprintf(`UPDATE %s
+    SET
+	    category_id = ?,
+	    title = ?,
+	    image_url = ?,
+	    price = ?,
+	    description = ?
+	WHERE %s = ?;`, e.TableName(), e.PrimaryKey())
+
+	res, err := s.DB().Exec(ctx, q, e.CategoryID, e.Title, e.ImageURL, e.Price, e.Description, e.ID)
+	if err != nil {
+		return 0, err
+	}
+
+	n := sql.GetAffectedRows(res)
+	return n, nil
+}
+
+var productUpdateSchema = map[string]reflect.Kind{
+	"category_id": reflect.Int,
+	"title":       reflect.String,
+	"image_url":   reflect.String,
+	"price":       reflect.Float32,
+	"description": reflect.String,
+}
+
+// PartialUpdate accepts a key-value map to
+// update the record based on the given "id".
+func (s *ProductService) PartialUpdate(ctx context.Context, id int64, attrs map[string]interface{}) (int, error) {
+	return s.Service.PartialUpdate(ctx, id, productUpdateSchema, attrs)
+}