sequelize association test

rootfs_overlay/lkmc/nodejs/sequelize/association.js

@@ -0,0 +1,92 @@
+#!/usr/bin/env node
+
+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 Comment = sequelize.define('Comment', {
+  body: { type: DataTypes.STRING },
+}, {});
+const User = sequelize.define('User', {
+  name: { type: DataTypes.STRING },
+}, {});
+User.hasMany(Comment)
+Comment.belongsTo(User)
+await sequelize.sync({force: true});
+const u0 = await User.create({name: 'u0'})
+const u1 = await User.create({name: 'u1'})
+await Comment.create({body: 'u0c0', UserId: u0.id});
+await Comment.create({body: 'u0c1', UserId: u0.id});
+await Comment.create({body: 'u1c0', UserId: u1.id});
+
+// Direct way.
+{
+  const u0Comments = await Comment.findAll({
+    where: { UserId: u0.id },
+    order: [['id', 'ASC']],
+  });
+  assert(u0Comments[0].body === 'u0c0');
+  assert(u0Comments[1].body === 'u0c1');
+  assert(u0Comments[0].UserId === u0.id);
+  assert(u0Comments[1].UserId === u0.id);
+  // Not added as an object by default. Would require extra query.
+  assert(u0Comments[0].User === undefined);
+  assert(u0Comments[1].User === undefined);
+}
+
+// Include data from the other side of the association in the query.
+{
+  const u0Comments = await Comment.findAll({
+    where: { UserId: u0.id },
+    order: [['id', 'ASC']],
+    include: [{ model: User }],
+  });
+  assert(u0Comments[0].body === 'u0c0');
+  assert(u0Comments[1].body === 'u0c1');
+  assert(u0Comments[0].UserId === u0.id);
+  assert(u0Comments[1].UserId === u0.id);
+  // These did get added now.
+  assert(u0Comments[0].User.name === 'u0');
+  assert(u0Comments[1].User.name === 'u0');
+}
+
+// Nicer higher level way.
+{
+  const u0Comments = await u0.getComments({
+    include: [{ model: User }],
+  });
+  assert(u0Comments[0].body === 'u0c0');
+  assert(u0Comments[1].body === 'u0c1');
+  assert(u0Comments[0].User.name === 'u0');
+  assert(u0Comments[1].User.name === 'u0');
+}
+
+// No way to create new item with association without explicit foreign key??
+// https://stackoverflow.com/questions/34059081/how-do-i-reference-an-association-when-creating-a-row-in-sequelize-without-assum
+// This does not work as we would like:
+{
+  await Comment.create({body: 'u0c2', User: u0});
+  // We'd want 3 here.
+  assert((await Comment.findAll({
+    where: { UserId: u0.id },
+  })).length === 2);
+}
+
+// Removal auto-cascades.
+const u0id = u0.id
+await u0.destroy()
+assert((await Comment.findAll({
+  where: { UserId: u0id },
+})).length === 0);
+assert((await Comment.findAll({
+  where: { UserId: u1.id },
+})).length === 1);
+
+await sequelize.close();
+})();

rootfs_overlay/lkmc/nodejs/sequelize/index.js

@@ -11,6 +11,7 @@
 //   ``
 
 const assert = require('assert');
+const path = require('path');
 
 const { Sequelize, DataTypes } = require('sequelize');
 
@@ -29,7 +30,7 @@ const { Sequelize, DataTypes } = require('sequelize');
 //});
 const sequelize = new Sequelize({
   dialect: 'sqlite',
-  storage: 'tmp.sequelize.sqlite',
+  storage: 'tmp.' + path.basename(__filename) + '.sqlite',
 });
 
 // OMG fuck this asynchronous bullshit: