package handlers import ( "net/http" "github.com/gin-gonic/gin" "fishfish/database" ) func GetTopItems(c *gin.Context) { type TopItem struct { Name string `json:"name"` Revenue float64 `json:"revenue"` Price float64 `json:"price"` SaleQuantity float64 `json:"sale_quantity"` Unit string `json:"unit"` } results := []TopItem{} err := database.DB.Table("order_items"). Select("items.name, SUM(order_items.price * order_items.quantity) AS revenue, order_items.price, SUM(order_items.quantity) as sale_quantity, items.unit"). Joins("JOIN items ON items.id = order_items.item_id"). Group("items.name, order_items.price, items.unit"). Order("revenue DESC"). Limit(5). Scan(&results).Error if err != nil { c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()}) } c.JSON(http.StatusOK, results) }