more sequelize will it ever end

rootfs_overlay/lkmc/nodejs/sequelize/association_many_to_many.js

@@ -49,6 +49,8 @@ const post2 = await Post.create({body: 'post2'});
 
 // Make user0 like post0
 await user0.addPost(post0)
+// Also works.
+//await user0.addPost(post0.id)
 // Make user0 and user2 like post1
 await post1.addUsers([user0, user2])
 
@@ -68,6 +70,20 @@ const user2Likes = await user2.getPosts({order: [['body', 'ASC']]})
 assert(user2Likes[0].body === 'post1');
 assert(user2Likes.length === 1);
 
+// Same as get* but with the user ID instead of the model object.
+{
+  const user0Likes = await Post.findAll({
+    include: [{
+      model: User,
+      where: {id: user0.id},
+    }],
+    order: [['body', 'ASC']],
+  })
+  assert(user0Likes[0].body === 'post0');
+  assert(user0Likes[1].body === 'post1');
+  assert(user0Likes.length === 2);
+}
+
 // Get users that liked a given likes.
 
 const post0Likers = await post0.getUsers({order: [['name', 'ASC']]})
@@ -88,6 +104,7 @@ assert(post1Likers.length === 2);
 
 // Check if user likes post.
 assert( await user0.hasPost(post0))
+assert( await user0.hasPost(post0.id)) // same
 assert( await user0.hasPost(post1))
 assert(!await user0.hasPost(post2))
 
@@ -104,7 +121,7 @@ assert(!await user0.hasPosts([post0, post1, post2]))
 assert(await user0.countPosts() === 2)
 assert(await post0.countUsers() === 1)
 
-// Autogenerated remove* method
+// Autogenerated remove* methods
 
 // user0 doesn't like post0 anymore.
 await user0.removePost(post0)

rootfs_overlay/lkmc/nodejs/sequelize/association_many_to_many_custom_table.js

@@ -67,14 +67,40 @@ const post2 = await Post.create({body: 'post2'});
 
 // Autogenerated add* methods
 
-// Make user0 like post0
+// Make some useres like some posts.
-await user0.addPost(post0, {through: { score: 1 }})
+await user0.addPost(post0, {through: {score: 1}})
+await user1.addPost(post1, {through: {score: 2}})
+await user1.addPost(post2, {through: {score: 3}})
 
+// Find what user0 likes.
 const user0Likes = await user0.getPosts({order: [['body', 'ASC']]})
 assert(user0Likes[0].body === 'post0');
 assert(user0Likes[0].UserLikesPost.score === 1);
 assert(user0Likes.length === 1);
 
+// Find what user1 likes.
+const user1Likes = await user1.getPosts({order: [['body', 'ASC']]})
+assert(user1Likes[0].body === 'post1');
+assert(user1Likes[0].UserLikesPost.score === 2);
+assert(user1Likes[1].body === 'post2');
+assert(user1Likes[1].UserLikesPost.score === 3);
+assert(user1Likes.length === 2);
+
+// Where on the custom through table column.
+// https://stackoverflow.com/questions/38857156/how-to-query-many-to-many-relationship-sequelize
+{
+  const user1LikesWithScore3 = await Post.findAll({
+    include: [{
+      model: User,
+      where: {id: user1.id},
+      through: {where: {score: 3}},
+    }],
+  })
+  assert(user1LikesWithScore3[0].body === 'post2');
+  assert(user1LikesWithScore3[0].UserLikesPost.score === 3);
+  assert(user1LikesWithScore3.length === 1);
+}
+
 // TODO: this doesn't work. Possible at all in a single addUsers call?
 // Make user0 and user2 like post1
 // This method automatically generated.

rootfs_overlay/lkmc/nodejs/sequelize/association_many_to_many_same_model.js

@@ -18,7 +18,7 @@ const sequelize = new Sequelize({
 const User = sequelize.define('User', {
   name: { type: DataTypes.STRING },
 }, {});
-User.belongsToMany(User, {through: 'UserFollowsUser', as: 'Follow'});
+User.belongsToMany(User, {through: 'UserFollowUser', as: 'Follows'});
 await sequelize.sync({force: true});
 
 // Create some users.
@@ -29,12 +29,48 @@ const user2 = await User.create({name: 'user2'})
 const user3 = await User.create({name: 'user3'})
 
 // Make user0 follow user1 and user2
-await user0.addFollow(user1)
+await user0.addFollows([user1, user2])
-await user0.addFollow(user2)
+// Make user2 and user3 follow user0
-const user0Follows = await user0.getFollow({order: [['name', 'ASC']]})
+await user2.addFollow(user0)
+await user3.addFollow(user0)
+
+// Check that the follows worked.
+const user0Follows = await user0.getFollows({order: [['name', 'ASC']]})
 assert(user0Follows[0].name === 'user1');
 assert(user0Follows[1].name === 'user2');
 assert(user0Follows.length === 2);
 
+const user1Follows = await user1.getFollows({order: [['name', 'ASC']]})
+assert(user1Follows.length === 0);
+
+const user2Follows = await user2.getFollows({order: [['name', 'ASC']]})
+assert(user2Follows[0].name === 'user0');
+assert(user2Follows.length === 1);
+
+const user3Follows = await user3.getFollows({order: [['name', 'ASC']]})
+assert(user3Follows[0].name === 'user0');
+assert(user3Follows.length === 1);
+
+// Same but with ID instead of object.
+{
+  const user0Follows = (await User.findOne({
+    where: {id: user0.id},
+    include: [{model: User, as: 'Follows'}],
+  })).Follows
+  assert(user0Follows[0].name === 'user1');
+  assert(user0Follows[1].name === 'user2');
+  assert(user0Follows.length === 2);
+}
+
+// has methods
+assert(!await user0.hasFollow(user0))
+assert(!await user0.hasFollow(user0.id))
+assert( await user0.hasFollow(user1))
+assert( await user0.hasFollow(user2))
+assert(!await user0.hasFollow(user3))
+
+// Count method
+assert(await user0.countFollows() === 2)
+
 await sequelize.close();
 })();

rootfs_overlay/lkmc/nodejs/sequelize/association_nested_include.js

@@ -0,0 +1,235 @@
+#!/usr/bin/env node
+
+// Find all posts by users that a given user follows.
+// https://stackoverflow.com/questions/42632943/sequelize-multiple-where-clause
+
+const assert = require('assert');
+const path = require('path');
+
+const { Sequelize, DataTypes } = require('sequelize');
+
+const sequelize = new Sequelize({
+  dialect: 'sqlite',
+  storage: 'tmp.' + path.basename(__filename) + '.sqlite',
+});
+
+(async () => {
+
+// Create the tables.
+const User = sequelize.define('User', {
+  name: { type: DataTypes.STRING },
+}, {});
+const Post = sequelize.define('Post', {
+  body: { type: DataTypes.STRING },
+}, {});
+User.belongsToMany(User, {through: 'UserFollowUser', as: 'Follows'});
+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: 'body00', UserId: users[0].id},
+  {body: 'body11', UserId: users[0].id},
+  {body: 'body10', UserId: users[1].id},
+  {body: 'body11', UserId: users[1].id},
+  {body: 'body20', UserId: users[2].id},
+  {body: 'body21', UserId: users[2].id},
+  {body: 'body30', UserId: users[3].id},
+  {body: 'body31', UserId: users[3].id},
+])
+
+await users[0].addFollows([users[1], users[2]])
+
+// Get all posts by authors that user0 follows.
+// The posts are placed inside their respetive authors under .Posts
+// so we loop to gather all of them.
+{
+  const user0Follows = (await User.findByPk(users[0].id, {
+    include: [
+      {
+        model: User,
+        as: 'Follows',
+        include: [
+          {
+            model: Post,
+          }
+        ],
+      },
+    ],
+  })).Follows
+  const postsFound = []
+  for (const followedUser of user0Follows) {
+    postsFound.push(...followedUser.Posts)
+  }
+  postsFound.sort((x, y) => { return x.body < y.body ? -1 : x.body > y.body ? 1 : 0 })
+  assert(postsFound[0].body === 'body10')
+  assert(postsFound[1].body === 'body11')
+  assert(postsFound[2].body === 'body20')
+  assert(postsFound[3].body === 'body21')
+  assert(postsFound.length === 4)
+}
+
+// With ordering, offset and limit.
+// The posts are placed inside their respetive authors under .Posts
+// The only difference is that posts that we didn't select got removed.
+
+{
+  const user0Follows = (await User.findByPk(users[0].id, {
+    offset: 1,
+    limit: 2,
+    // TODO why is this needed? It does try to make a subquery otherwise, and then it doesn't work.
+    // https://selleo.com/til/posts/ddesmudzmi-offset-pagination-with-subquery-in-sequelize-
+    subQuery: false,
+    include: [
+      {
+        model: User,
+        as: 'Follows',
+        include: [
+          {
+            model: Post,
+          }
+        ],
+      },
+    ],
+  })).Follows
+  assert(user0Follows[0].name === 'user1')
+  assert(user0Follows[1].name === 'user2')
+  assert(user0Follows.length === 2)
+  const postsFound = []
+  for (const followedUser of user0Follows) {
+    postsFound.push(...followedUser.Posts)
+  }
+  postsFound.sort((x, y) => { return x.body < y.body ? -1 : x.body > y.body ? 1 : 0 })
+  // Note that what happens is that some of the
+  assert(postsFound[0].body === 'body11')
+  assert(postsFound[1].body === 'body20')
+  assert(postsFound.length === 2)
+
+  // Same as above, but now with DESC ordering.
+  {
+    const user0Follows = (await User.findByPk(users[0].id, {
+      order: [[
+        {model: User, as: 'Follows'},
+        Post,
+        'body',
+        'DESC'
+      ]],
+      offset: 1,
+      limit: 2,
+      subQuery: false,
+      include: [
+        {
+          model: User,
+          as: 'Follows',
+          include: [
+            {
+              model: Post,
+            }
+          ],
+        },
+      ],
+    })).Follows
+    // Note how user ordering is also reversed from an ASC.
+    // it likely takes the use that has the first post.
+    assert(user0Follows[0].name === 'user2')
+    assert(user0Follows[1].name === 'user1')
+    assert(user0Follows.length === 2)
+    const postsFound = []
+    for (const followedUser of user0Follows) {
+      postsFound.push(...followedUser.Posts)
+    }
+    // In this very specific data case, this would not be needed.
+    // because user2 has the second post body and user1 has the first
+    // alphabetically.
+    postsFound.sort((x, y) => { return x.body < y.body ? 1 : x.body > y.body ? -1 : 0 })
+    // Note that what happens is that some of the
+    assert(postsFound[0].body === 'body20')
+    assert(postsFound[1].body === 'body11')
+    assert(postsFound.length === 2)
+  }
+
+  // Here user2 would have no post hits due to the limit,
+  // so it is entirely pruned from the user list as desired.
+  // Otherwise we would fetch a lot of unwanted user data
+  // in a large database.
+  const user0FollowsLimit2 = (await User.findByPk(users[0].id, {
+    limit: 2,
+    subQuery: false,
+    include: [
+      {
+        model: User,
+        as: 'Follows',
+        include: [ { model: Post } ],
+      },
+    ],
+  })).Follows
+  assert(user0FollowsLimit2[0].name === 'user1')
+  assert(user0FollowsLimit2.length === 1)
+
+  // Case in which our post-sorting is needed.
+  // TODO: possible to get sequelize to do this for us by returning
+  // a flat array directly?
+  // It's not big deal since the LIMITed result should be small,
+  // but feels wasteful.
+  // https://stackoverflow.com/questions/41502699/return-flat-object-from-sequelize-with-association
+  // https://github.com/sequelize/sequelize/issues/4419
+  {
+    await Post.truncate({restartIdentity: true})
+    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},
+    ])
+    const user0Follows = (await User.findByPk(users[0].id, {
+      order: [[
+        {model: User, as: 'Follows'},
+        Post,
+        'body',
+        'DESC'
+      ]],
+      subQuery: false,
+      include: [
+        {
+          model: User,
+          as: 'Follows',
+          include: [
+            {
+              model: Post,
+            }
+          ],
+        },
+      ],
+    })).Follows
+    assert(user0Follows[0].name === 'user2')
+    assert(user0Follows[1].name === 'user1')
+    assert(user0Follows.length === 2)
+    const postsFound = []
+    for (const followedUser of user0Follows) {
+      postsFound.push(...followedUser.Posts)
+    }
+    // We need this here, otherwise we would get all user2 posts first:
+    // body6, body2, body5, body1
+    postsFound.sort((x, y) => { return x.body < y.body ? 1 : x.body > y.body ? -1 : 0 })
+    assert(postsFound[0].body === 'body6')
+    assert(postsFound[1].body === 'body5')
+    assert(postsFound[2].body === 'body2')
+    assert(postsFound[3].body === 'body1')
+    assert(postsFound.length === 4)
+  }
+}
+
+await sequelize.close();
+})();

rootfs_overlay/lkmc/nodejs/sequelize/index.js

@@ -96,7 +96,7 @@ await IntegerNames.create({value: 5, name: 'five'});
 //   3 |     5 | five  | 2021-03-19 19:12:08.437+00 | 2021-03-19 19:12:08.437+00
 // (3 rows)
 
-let integerNames = await IntegerNames.findAll({
+const integerNames = await IntegerNames.findAll({
   where: {
     value: 2
   }

rootfs_overlay/lkmc/nodejs/sequelize/truncate_key.js

@@ -0,0 +1,36 @@
+#!/usr/bin/env node
+
+// https://stackoverflow.com/questions/39765582/in-sequelize-model-destroy-truncate-true-does-not-reset-primary-key
+
+const assert = require('assert')
+const path = require('path')
+
+const { Sequelize, DataTypes } = require('sequelize')
+
+const sequelize = new Sequelize({
+  dialect: 'sqlite',
+  storage: 'tmp.' + path.basename(__filename) + '.sqlite',
+})
+
+;(async () => {
+const IntegerNames = sequelize.define('IntegerNames', {
+  value: {
+    type: DataTypes.INTEGER,
+    allowNull: false,
+    unique: true,
+  },
+  name: {
+    type: DataTypes.STRING,
+  },
+}, {})
+await IntegerNames.sync({force: true})
+await IntegerNames.create({value: 2, name: 'two'})
+await IntegerNames.create({value: 3, name: 'three'})
+console.error((await IntegerNames.findOne({where: {value: 2}})).id)
+await IntegerNames.truncate({cascade: true})
+await IntegerNames.create({value: 5, name: 'five'})
+await IntegerNames.create({value: 7, name: 'seven'})
+console.error((await IntegerNames.findOne({where: {value: 5}})).id)
+
+await sequelize.close()
+})();