error in sequelize > "name": "SequelizeEagerLoadingError" - mysql

Question

I have two tables:
//User.js
module.exports = (sequelize, DataTypes) => {
const User = sequelize.define("User", {
userId: {
type: DataTypes.STRING,
allowNull: false,
unique: true,
primaryKey: true,
},
email: {
type: DataTypes.STRING,
},
firstName: {
type: DataTypes.STRING,
allowNull: false,
},
lastName: {
type: DataTypes.STRING,
defaultValue: "",
},
password: {
type: DataTypes.STRING,
allowNull: false,
},
chapterId: {
type: DataTypes.STRING,
},
});
User.associate = (models) => {
User.belongsTo(models.Chapter, {
foreignKey: "chapterId",
targetKey: "chapterId",
as: "chapter",
});
};
return User;
};
and
//chapter table
module.exports = (sequelize, DataTypes) => {
const Chapter = sequelize.define("Chapter", {
chapterId: {
type: DataTypes.STRING,
allowNull: false,
unique: true,
primaryKey: true,
},
chapterName: {
type: DataTypes.STRING,
allowNull: false,
},
isChapterLocal: {
type: DataTypes.BOOLEAN,
allowNull: false,
},
});
Chapter.associate = (models) => {
};
return Chapter;
};
and i am trying to fetch users with chapters included into it.
let getAll = async (req, res) => {
try {
const userData = await db.User.findAll({
include: [
{
model: Chapter,
as: "chapter",
},
],
});
res.send(userData);
} catch (e) {
res.send(e);
}
};
how to include chapter id and chapter name from chapter table, as present in chapterId row for user table.
I am new to sequelize and MySQL and am unsure if the relation i have defined in the user model is good.
Do we need to define associations in both tables.

Answer 1

It should work as expected. E.g.
import { sequelize } from '../../db';
import { Model, DataTypes } from 'sequelize';
class User extends Model {}
User.init(
{
userId: {
type: DataTypes.STRING,
allowNull: false,
unique: true,
primaryKey: true,
},
email: {
type: DataTypes.STRING,
},
firstName: {
type: DataTypes.STRING,
allowNull: false,
},
lastName: {
type: DataTypes.STRING,
defaultValue: '',
},
password: {
type: DataTypes.STRING,
allowNull: false,
},
chapterId: {
type: DataTypes.STRING,
},
},
{ sequelize, modelName: 'User' },
);
class Chapter extends Model {}
Chapter.init(
{
chapterId: {
type: DataTypes.STRING,
allowNull: false,
unique: true,
primaryKey: true,
},
chapterName: {
type: DataTypes.STRING,
allowNull: false,
},
isChapterLocal: {
type: DataTypes.BOOLEAN,
allowNull: false,
},
},
{ sequelize, modelName: 'Chapter' },
);
User.belongsTo(Chapter, { foreignKey: 'chapterId', targetKey: 'chapterId', as: 'chapter' });
(async function test() {
try {
await sequelize.sync({ force: true });
// seed
await User.create(
{
userId: '1',
email: 'example#gmail.com',
firstName: 'Lin',
lastName: 'Du',
password: '123',
chapter: {
chapterId: '1',
chapterName: 'ok',
isChapterLocal: false,
},
},
{ include: [{ model: Chapter, as: 'chapter' }] },
);
// test
const userData = await User.findAll({
include: [{ model: Chapter, as: 'chapter' }],
raw: true,
});
console.log('userData:', userData);
} catch (error) {
console.log(error);
} finally {
sequelize.close();
}
})();
The execution results:
Executing (default): DROP TABLE IF EXISTS "User" CASCADE;
Executing (default): DROP TABLE IF EXISTS "Chapter" CASCADE;
Executing (default): DROP TABLE IF EXISTS "Chapter" CASCADE;
Executing (default): CREATE TABLE IF NOT EXISTS "Chapter" ("chapterId" VARCHAR(255) NOT NULL UNIQUE , "chapterName" VARCHAR(255) NOT NULL, "isChapterLocal" BOOLEAN NOT NULL, PRIMARY KEY ("chapterId"));
Executing (default): SELECT i.relname AS name, ix.indisprimary AS primary, ix.indisunique AS unique, ix.indkey AS indkey, array_agg(a.attnum) as column_indexes, array_agg(a.attname) AS column_names, pg_get_indexdef(ix.indexrelid) AS definition FROM pg_class t, pg_class i, pg_index ix, pg_attribute a WHERE t.oid = ix.indrelid AND i.oid = ix.indexrelid AND a.attrelid = t.oid AND t.relkind = 'r' and t.relname = 'Chapter' GROUP BY i.relname, ix.indexrelid, ix.indisprimary, ix.indisunique, ix.indkey ORDER BY i.relname;
Executing (default): DROP TABLE IF EXISTS "User" CASCADE;
Executing (default): CREATE TABLE IF NOT EXISTS "User" ("userId" VARCHAR(255) NOT NULL UNIQUE , "email" VARCHAR(255), "firstName" VARCHAR(255) NOT NULL, "lastName" VARCHAR(255) DEFAULT '', "password" VARCHAR(255) NOT NULL, "chapterId" VARCHAR(255) REFERENCES "Chapter" ("chapterId") ON DELETE NO ACTION ON UPDATE CASCADE, PRIMARY KEY ("userId"));
Executing (default): SELECT i.relname AS name, ix.indisprimary AS primary, ix.indisunique AS unique, ix.indkey AS indkey, array_agg(a.attnum) as column_indexes, array_agg(a.attname) AS column_names, pg_get_indexdef(ix.indexrelid) AS definition FROM pg_class t, pg_class i, pg_index ix, pg_attribute a WHERE t.oid = ix.indrelid AND i.oid = ix.indexrelid AND a.attrelid = t.oid AND t.relkind = 'r' and t.relname = 'User' GROUP BY i.relname, ix.indexrelid, ix.indisprimary, ix.indisunique, ix.indkey ORDER BY i.relname;
Executing (default): INSERT INTO "Chapter" ("chapterId","chapterName","isChapterLocal") VALUES ($1,$2,$3) RETURNING *;
Executing (default): INSERT INTO "User" ("userId","email","firstName","lastName","password","chapterId") VALUES ($1,$2,$3,$4,$5,$6) RETURNING *;
Executing (default): SELECT "User"."userId", "User"."email", "User"."firstName", "User"."lastName", "User"."password", "User"."chapterId", "chapter"."chapterId" AS "chapter.chapterId", "chapter"."chapterName" AS "chapter.chapterName", "chapter"."isChapterLocal" AS "chapter.isChapterLocal" FROM "User" AS "User" LEFT OUTER JOIN "Chapter" AS "chapter" ON "User"."chapterId" = "chapter"."chapterId";
userData: [ { userId: '1',
email: 'example#gmail.com',
firstName: 'Lin',
lastName: 'Du',
password: '123',
chapterId: '1',
'chapter.chapterId': '1',
'chapter.chapterName': 'ok',
'chapter.isChapterLocal': false } ]
Check the database:
node-sequelize-examples=# select * from "User";
userId | email | firstName | lastName | password | chapterId
--------+-------------------+-----------+----------+----------+-----------
1 | example#gmail.com | Lin | Du | 123 | 1
(1 row)
node-sequelize-examples=# select * from "Chapter";
chapterId | chapterName | isChapterLocal
-----------+-------------+----------------
1 | ok | f
(1 row)