条件查询

bin/main.go

@@ -49,6 +49,7 @@ type Images struct {
 	Page     int     `json:"page"`
 	PageSize int     `json:"page_size"`
 	Total    int     `json:"total"`
+	Next     bool    `json:"next"`
 	List     []Image `json:"list"`
 }
 
@@ -68,30 +69,40 @@ func main() {
 		// 排序
 		// 分页
 
-		// 按标签查询
-		var tags string
-		if list := strings.Split(r.URL.Query().Get("tags"), ","); len(list) > 0 {
-			for _, tag := range list {
-				tags += fmt.Sprintf("'%s',", tag)
+		// 获取查询条件(忽略空值), 超级简洁写法
+		QueryConditions := func(key string) (list []string) {
+			for _, item := range strings.Split(r.URL.Query().Get(key), ",") {
+				if item != "" {
+					list = append(list, fmt.Sprintf("'%s'", item))
+				}
 			}
-			tags = tags[:len(tags)-1]
-			fmt.Println(tags)
+			return list
 		}
 
-		// 按分类查询
-		var categories string
-		if list := strings.Split(r.URL.Query().Get("categories"), ","); len(list) > 0 {
-			for _, category := range list {
-				categories += fmt.Sprintf("'%s',", category)
-			}
-			categories = categories[:len(categories)-1]
-			fmt.Println(categories)
+		// 拼接查询条件, 超级简洁写法
+		conditions := ""
+		if authors := QueryConditions("authors"); len(authors) > 0 {
+			conditions += fmt.Sprintf(" AND author IN (%s)", strings.Join(authors, ","))
+		}
+		if tags := QueryConditions("tags"); len(tags) > 0 {
+			conditions += fmt.Sprintf(" AND tag IN (%s)", strings.Join(tags, ","))
+		}
+		if categories := QueryConditions("categories"); len(categories) > 0 {
+			conditions += fmt.Sprintf(" AND categorie IN (%s)", strings.Join(categories, ","))
+		}
+		if sets := QueryConditions("sets"); len(sets) > 0 {
+			conditions += fmt.Sprintf(" AND sets IN (%s)", strings.Join(sets, ","))
+		}
+		if conditions != "" {
+			conditions = strings.Replace(conditions, " AND", "", 1) // 去掉第一个 AND
+			conditions = " WHERE" + conditions                      // 拼接 WHERE
+			fmt.Println(conditions)                                 // 打印查询条件
 		}
 
 		// 获取图片列表
 		var images Images
 		images.Page, images.PageSize = stringToInt(r.URL.Query().Get("page"), 1), stringToInt(r.URL.Query().Get("pageSize"), 10)
-		rows, err := mysqlConnection.Database.Query("SELECT id, content, update_time, create_time FROM web_images LIMIT ?, ?", (images.Page-1)*images.PageSize, images.PageSize)
+		rows, err := mysqlConnection.Database.Query("SELECT id, content, update_time, create_time FROM web_images"+conditions+" LIMIT ?, ?", (images.Page-1)*images.PageSize, images.PageSize)
 		if err != nil {
 			log.Println("获取图片列表失败", err)
 			http.Error(w, err.Error(), http.StatusBadRequest)
@@ -110,13 +121,16 @@ func main() {
 		}
 
 		// 获取总数
-		err = mysqlConnection.Database.QueryRow("SELECT COUNT(*) FROM web_images").Scan(&images.Total)
+		err = mysqlConnection.Database.QueryRow("SELECT COUNT(*) FROM web_images" + conditions).Scan(&images.Total)
 		if err != nil {
 			log.Println("获取图片总数失败", err)
 			http.Error(w, err.Error(), http.StatusBadRequest)
 			return
 		}
 
+		// 是否有下一页
+		images.Next = images.Total > images.Page*images.PageSize
+
 		// 将对象转换为有缩进的JSON输出
 		data, err := json.MarshalIndent(images, "", "  ")
 		if err != nil {