managed

rootfs_overlay/lkmc/nodejs/sequelize/association_nested_include_super.js

@@ -0,0 +1,112 @@
+#!/usr/bin/env node
+
+// Like association_nested_include.js but with a super many to many.
+
+const assert = require('assert');
+const path = require('path');
+
+const { Sequelize, DataTypes, Op } = require('sequelize');
+
+const sequelize = new Sequelize({
+  dialect: 'sqlite',
+  storage: 'tmp.' + path.basename(__filename) + '.sqlite',
+  define: {
+    timestamps: false
+  },
+});
+
+(async () => {
+
+// Create the tables.
+const User = sequelize.define('User', {
+  name: { type: DataTypes.STRING },
+});
+const Post = sequelize.define('Post', {
+  body: { type: DataTypes.STRING },
+});
+const UserFollowUser = sequelize.define('UserFollowUser', {
+    UserId: {
+      type: DataTypes.INTEGER,
+      references: {
+        model: User,
+        key: 'id'
+      }
+    },
+    FollowId: {
+      type: DataTypes.INTEGER,
+      references: {
+        model: User,
+        key: 'id'
+      }
+    },
+  }
+);
+
+// Super many to many.
+User.belongsToMany(User, {through: UserFollowUser, as: 'Follows'});
+UserFollowUser.belongsTo(User)
+User.hasMany(UserFollowUser)
+
+User.hasMany(Post);
+Post.belongsTo(User);
+
+await sequelize.sync({force: true});
+
+// Create data.
+const users = await User.bulkCreate([
+  {name: 'user0'},
+  {name: 'user1'},
+  {name: 'user2'},
+  {name: 'user3'},
+])
+const posts = await Post.bulkCreate([
+  {body: 'body0', UserId: users[0].id},
+  {body: 'body1', UserId: users[1].id},
+  {body: 'body2', UserId: users[2].id},
+  {body: 'body3', UserId: users[3].id},
+  {body: 'body4', UserId: users[0].id},
+  {body: 'body5', UserId: users[1].id},
+  {body: 'body6', UserId: users[2].id},
+  {body: 'body7', UserId: users[3].id},
+])
+await users[0].addFollows([users[1], users[2]])
+
+// Get all the posts by authors that user0 follows.
+// without post process sorting. We only managed to to this
+// with a super many to many, because that allows us to specify
+// a reversed order in the through table with `on`, since we need to
+// match with `FollowId` and not `UserId`.
+{
+  const postsFound = await Post.findAll({
+    order: [[
+      'body',
+      'DESC'
+    ]],
+    include: [
+      {
+        model: User,
+        attributes: [],
+        required: true,
+        include: [
+          {
+            model: UserFollowUser,
+            on: {
+              FollowId: {[Op.col]: 'User.id' },
+            },
+            attributes: [],
+            where: {UserId: users[0].id},
+          }
+        ],
+      },
+    ],
+  })
+  console.error(postsFound.length);
+  assert.strictEqual(postsFound[0].body, 'body6')
+  assert.strictEqual(postsFound[1].body, 'body5')
+  assert.strictEqual(postsFound[2].body, 'body2')
+  assert.strictEqual(postsFound[3].body, 'body1')
+  assert.strictEqual(postsFound.length, 4)
+}
+
+await sequelize.close();
+})();