Display all bands grouped by genre, create m:n association between Band and Genre in database

software/src/scripts/showsScripts.ts

@@ -1,3 +1,5 @@
+import { RatingModel } from "@/data/models/ratingModel"
+
 /**
  * Calculate a price based on parameters
  * 
@@ -9,4 +11,21 @@
  */
 export function calcPrice(price: number, discount: number = 0, quantity: number = 1): number {
   return Math.round(quantity * price * ((100 - discount) / 100) * 100) / 100
+}
+
+/**
+ * Calculate the average of an Array of ratings
+ * 
+ * @param ratings Array of ratings
+ * 
+ * @returns Average rating as number
+ */
+export function calcRating(ratings: Array<RatingModel>) {
+  let sum = 0
+
+  for (let rating of ratings) {
+    sum += rating.rating
+  }
+
+  return sum / ratings.length
 }