Added new structure by name Records for holding totalRecords. Deleted…

… TotalRecords field from Product structure as it is a bad practice.

db/db.go

@@ -6,7 +6,7 @@ import (
 )
 
 type Storer interface {
-	ListProducts(context.Context, int, int) ([]Product, error)
+	ListProducts(context.Context, int, int) (int, []Product, error)
 	FilteredProducts(context.Context, Filter, string, string) (int, []Product, error)
 	SearchProductsByText(context.Context, string, string, string) (int, []Product, error)
 	CreateProduct(context.Context, Product, []*multipart.FileHeader) (Product, error)

db/product.go

@@ -52,7 +52,6 @@ type Product struct {
 	Color        string         `db:"color" json:"color,*" schema:"color,*"`
 	Size         string         `db:"size" json:"size,*" schema:"size,*"`
 	URLs         pq.StringArray `db:"image_urls" json:"image_urls,*"  schema:"images"`
-	TotalRecords int            `db:"total" json:"-"`
 }
 
 // Pagination helps to return UI side with number of pages given a limitStr and pageStr number from Query Parameters
@@ -61,6 +60,11 @@ type Pagination struct {
 	TotalPages int       `json:"total_pages"`
 }
 
+type Record struct {
+	TotalRecords int `db:"total"`
+	Product
+}
+
 func (product *Product) Validate() (map[string]ErrorResponse, bool) {
 	var errorResponse map[string]ErrorResponse
 	var valid bool
@@ -183,34 +187,26 @@ func (s *pgStore) GetProductByID(ctx context.Context, id int) (Product, error) {
 // @Description Get limited number of Products of particular pageStr
 // @Params req.Context , limitStr, pageStr
 // @Returns Count of Records, error if any
-func (s *pgStore) ListProducts(ctx context.Context, limit int, offset int) ([]Product, error) {
+func (s *pgStore) ListProducts(ctx context.Context, limit int, offset int) (int, []Product, error) {
 
 	var products []Product
+	var records []Record
 
-	result, err := s.db.Queryx(getProductQuery, limit, offset)
+	err := s.db.Select(&records, getProductQuery, limit, offset)
 	if err != nil {
 		logger.WithField("err", err.Error()).Error("Error fetching Products from database")
-		return []Product{}, err
-	}
-	for result.Next() {
-		var product Product
-		err = result.StructScan(&product)
-		if err != nil {
-			logger.WithField("err", err.Error()).Error("Error scanning Products from database")
-			return []Product{}, err
-		}
-		products = append(products, product)
+		return 0, []Product{}, err
+	} else if len(records) == 0 {
+		err = fmt.Errorf("Either Offset was big or No Records Present in database!")
+		logger.WithField("err", err.Error()).Error("database Returned total record count as 0")
+		return 0, []Product{}, err
 	}
-	//fmt.Println(products)
 
-	if len(products) > 0 && products[0].TotalRecords-1 >= offset {
-		return products, nil
-	} else {
-		err = fmt.Errorf("Page out of Range or No Records Present!")
-		logger.WithField("err", err.Error()).Error("Error Offset is greater than total records")
-		return []Product{}, err
+	for _, record := range records {
+		products = append(products, record.Product)
 	}
 
+	return records[0].TotalRecords, products, nil
 }
 
 func (s *pgStore) CreateProduct(ctx context.Context, product Product, images []*multipart.FileHeader) (Product, error) {

service/filters_http.go

@@ -174,12 +174,12 @@ func getProductBySearchHandler(deps Dependencies) http.HandlerFunc {
 		offsetStr := strconv.Itoa(offset)
 		if text == "" {
 			// Behave same as List All Products and return
-			products, err = deps.Store.ListProducts(req.Context(), limit, offset)
+			totalRecords, products, err = deps.Store.ListProducts(req.Context(), limit, offset)
 
-			if err != nil || products[0].TotalRecords == 0 {
+			if err != nil {
 				logger.WithField("err", err.Error()).Error("Error Couldn't find any Product records or Page out of range")
 				Message := "Couldn't find any Products records or Page out of range"
-				responseMsg(rw, http.StatusBadRequest, Message)
+				responseMsg(rw, http.StatusInternalServerError, Message)
 				return
 			}
 			goto Skip
@@ -191,13 +191,11 @@ func getProductBySearchHandler(deps Dependencies) http.HandlerFunc {
 			Message := "Couldn't find any matching search records or Page out of range"
 			responseMsg(rw, http.StatusBadRequest, Message)
 			return
-		} else {
-			products[0].TotalRecords = totalRecords
 		}
 
 	Skip:
 		var pagination db.Pagination
-		pagination.TotalPages = int(math.Ceil(float64(products[0].TotalRecords) / float64(limit)))
+		pagination.TotalPages = int(math.Ceil(float64(totalRecords) / float64(limit)))
 		pagination.Products = products
 		response(rw, http.StatusOK, pagination)
 		return

service/product_http.go

@@ -57,17 +57,17 @@ func listProductsHandler(deps Dependencies) http.HandlerFunc {
 			return
 		}
 		offset := (page - 1) * limit
-		products, err := deps.Store.ListProducts(req.Context(), limit, offset)
+		totalRecords, products, err := deps.Store.ListProducts(req.Context(), limit, offset)
 
-		if err != nil || products[0].TotalRecords == 0 {
+		if err != nil {
 			logger.WithField("err", err.Error()).Error("Error Couldn't find any Product records or Page out of range")
 			Message := "Couldn't find any Products records or Page out of range"
 			responseMsg(rw, http.StatusInternalServerError, Message)
 			return
 		}
 
 		var pagination db.Pagination
-		pagination.TotalPages = int(math.Ceil(float64(products[0].TotalRecords) / float64(limit)))
+		pagination.TotalPages = int(math.Ceil(float64(totalRecords) / float64(limit)))
 		pagination.Products = products
 		response(rw, http.StatusOK, pagination)
 		return