diff --git a/src/config.ts b/src/config.ts
index ea07084..d8b9bfa 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -12,6 +12,8 @@ export const dbConfig = {
         return 'product-products';
       } else if (output === 'order_rows_fields') {
         return 'order-rows_fields';
+      } else if (output === 'product_products_products') {
+        return 'product-products_products';
       }
       return output;
     },
diff --git a/src/datasources/product-api.ts b/src/datasources/product-api.ts
index 31e6933..eb25911 100644
--- a/src/datasources/product-api.ts
+++ b/src/datasources/product-api.ts
@@ -19,6 +19,7 @@ import {
 } from '../types/product-types';
 import { Maybe } from '../types/types';
 import { booleanStringField, nullOrNumber } from './utils';
+import { UserInputError } from 'apollo-server';
 
 const MINUTE = 60;
 
@@ -33,7 +34,10 @@ export class ProductAPI extends BaseSQLDataSource {
   // }
 
   getWallpaperTypes(row: any): Array<ProductWallpaperType> {
-    return row.wallpapertypes?.map((t: number) => ProductWallpaperType[t]);
+    if (!row.wallpapertypes) {
+      return [];
+    }
+    return row.wallpapertypes.map((t: number) => ProductWallpaperType[t]);
   }
 
   getProductTypes(row: any): Array<ProductType> {
@@ -185,10 +189,10 @@ export class ProductAPI extends BaseSQLDataSource {
   }
 
   async getRelatedProducts(id: number): Promise<Array<Product>> {
-    const ids = await this.cachedRaw(
-      `SELECT productid2 FROM "product-products_products" WHERE productid1 = ${id}`,
-    )
-      .cache(MINUTE * 60)
+    const ids = await this.knex
+      .raw(
+        `SELECT productid2 FROM "product-products_products" WHERE productid1 = ${id}`,
+      )
       .then((data) => data.rows.map((r) => r.productid2));
 
     return ids.map(async (id) => this.getProduct(id));
@@ -471,4 +475,65 @@ export class ProductAPI extends BaseSQLDataSource {
 
     return Promise.all(promises);
   }
+
+  async addRelatedProducts(
+    productId: number,
+    articleNumbers: Array<string>,
+  ): Promise<Promise<void>[]> {
+    const whereClause = articleNumbers.map((a) => `'${a}'`).join(',');
+    const query = /* sql */ `
+    SELECT pp.productid, ppf.value FROM "product-products" pp
+      LEFT JOIN "product-products_fields" ppf
+      ON ppf.productid = pp.productid AND ppf.fieldid = 1
+      WHERE ppf.value IN (${whereClause});
+    `;
+
+    const res = await this.cachedRaw(query)
+      .cache(MINUTE)
+      .then((data) => data.rows);
+
+    if (!res.length) {
+      throw new UserInputError('No articles found');
+    }
+    const fieldsToInsert = res.map((item) => ({
+      productid1: productId,
+      productid2: item.productid,
+    }));
+
+    // Add this productId as related to its friends
+    res.forEach((item) => {
+      fieldsToInsert.push({
+        productid1: item.productid,
+        productid2: productId,
+      });
+    });
+
+    return this.knex.raw(`? ON CONFLICT (productid1, productid2) DO NOTHING;`, [
+      this.knex('product-products_products').insert(fieldsToInsert),
+    ]);
+  }
+
+  /**
+   * Removes variant products from productid as well as the sent in
+   * productid from its variants
+   */
+  async removeRelatedProducts(
+    productId,
+    relatedProductIds,
+  ): Promise<Promise<void>[]> {
+    // remove connection between the friends id and this produdId
+    const promises = relatedProductIds.map((pId) => {
+      return this.knex('product-products_products')
+        .where('productid1', pId)
+        .where('productid2', productId)
+        .del();
+    });
+    // remove connection to friends for this productsid
+    const query = this.knex('product-products_products')
+      .where('productid1', productId)
+      .whereIn('productid2', relatedProductIds)
+      .del();
+    promises.push(query);
+    return Promise.all(promises);
+  }
 }
diff --git a/src/resolvers/products-resolver.ts b/src/resolvers/products-resolver.ts
index 5f7e744..cd65f2a 100644
--- a/src/resolvers/products-resolver.ts
+++ b/src/resolvers/products-resolver.ts
@@ -161,4 +161,23 @@ export const productMutationTypeDefs = {
     );
     return (<ProductAPI>dataSources.productApi).getProduct(productId);
   },
+  async addRelatedProducts(_, { productId, articleNumbers }, { dataSources }) {
+    await (<ProductAPI>dataSources.productApi).addRelatedProducts(
+      productId,
+      articleNumbers,
+    );
+    return (<ProductAPI>dataSources.productApi).getProduct(productId);
+  },
+
+  async removeRelatedProducts(
+    _,
+    { productId, relatedProductIds },
+    { dataSources },
+  ) {
+    await (<ProductAPI>dataSources.productApi).removeRelatedProducts(
+      productId,
+      relatedProductIds,
+    );
+    return (<ProductAPI>dataSources.productApi).getProduct(productId);
+  },
 };
diff --git a/src/schema.graphql b/src/schema.graphql
index 556fe1c..1c58151 100644
--- a/src/schema.graphql
+++ b/src/schema.graphql
@@ -263,7 +263,7 @@ type Product {
   ref2: String
   ref3: String
   related: [Product]
-  wallpaperTypes: [ProductWallpaperType]
+  wallpaperTypes: [ProductWallpaperType]!
   fields: ProductFields
   orientation: Orientation
   """
@@ -454,5 +454,9 @@ type Mutation {
     productId: Int!
     wallpaperTypes: [ProductWallpaperType]!
   ): Product
+
+  addRelatedProducts(productId: Int!, articleNumbers: [String]!): Product
+  removeRelatedProducts(productId: Int!, relatedProductIds: [Int]!): Product
+
   addKeyword(name: String!, type: KeywordType): Keyword
 }