I don't see the junction tables getting created for my code below (for UserEvents as:Attendees). When I try to add 'Attendee' to an Event using event.setAttendees([user]), it sets the EventId on the user table (thus making it a one-to-many relationship)
During sync logging, no tables with 'userevents' related name gets created
var User = db.import(__dirname + '/user');
var Event = db.import(__dirname + '/event');
Event.hasMany(User, { as: 'Attendees'});
User.hasMany(Event);
db.sync({logging: console.log}).success(function() {
logger.info('DB Initialization successful!');
createDefaultData()
}).error(function(err) {
logger.error('DB Initialization failed!', err);
});
var createDefaultData = function() {
User.create({email:"test#test.com", firstName: "tolga", lastName: "ekmen", password: "qwer", location: "13424"});
}
When using an alias ({ as: 'Attendees'}) you have to tell sequelize that you want a join table, by specifying through, which can either be a string or a model:
Event.hasMany(User, { as: 'Attendees', through: 'user_events' });
User.hasMany(Event, { , through: 'user_events' });
Related
I have multiple models which are associated to each other.
e.g:
var User = sequelize.define("user")
var Project = sequelize.define("project")
Project.hasMany(User)
Now I want to query all Projects containing a specific user.
e.g.:
Project.findAll({
include: [
{
model: User,
where: { id }
}
]
})
This works, but loads also the user and attaches it to the project.
How can I tell sequelize, that the user should not be added to the found projects?
I just managed to address the same problem (using Sequelize 4).
You can specify that you don't want any fields of User just using attributes: [], so your code would become:
Project.findAll({
include: [
{
attributes: [],
model: User,
where: { id }
}
]
})
Many-to-many relationships are defined using the belongsToMany() method in sequelize on both sides. For your specific use case you would have to use a through model for the relation and query the through model directly.
var User = sequelize.define("user")
var Project = sequelize.define("project")
var ProjectUser = sequelize.define("projectUser")
Project.belongsToMany(User, {
through: ProjectUser
})
User.belongsToMany(Project, {
through ProjectUser
});
ProjectUser.findAll({
where: {
UserId: 'someId'
},
// We only want the project, not the user.
// You might need to do ProjectUser.belongsTo() for both
// models for this to work.
include: [Project]
})
.then(function(results) {
// Here we are getting an array of ProjectUsers, to return all the projects
// we map it to a new array of only projects.
return results.map(function(userProject) {
return userProject.Project;
});
})
I have the following code:
#!/usr/bin/env node
'use strict';
var Sequelize = require('sequelize');
var sequelize = new Sequelize('sqlite:file.sqlite');
var User = sequelize.define('User', { email: Sequelize.STRING});
var Thing = sequelize.define('Thing', { name: Sequelize.STRING});
Thing.belongsTo(User);
sequelize.sync({force: true}).then(function () {
return User.create({email: 'asdf#example.org'});
}).then(function (user) {
return Thing.create({
name: 'A thing',
User: user
}, {
include: [User]
});
}).then(function (thing) {
return Thing.findOne({where: {id: thing.id}, include: [User]});
}).then(function (thing) {
console.log(JSON.stringify(thing));
});
I get the following output:
ohnobinki#gibby ~/public_html/turbocase1 $ ./sqltest.js
Executing (default): INSERT INTO `Users` (`id`,`email`,`updatedAt`,`createdAt`) VALUES (NULL,'asdf#example.org','2015-12-03 06:11:36.904 +00:00','2015-12-03 06:11:36.904 +00:00');
Executing (default): INSERT INTO `Users` (`id`,`email`,`createdAt`,`updatedAt`) VALUES (1,'asdf#example.org','2015-12-03 06:11:36.904 +00:00','2015-12-03 06:11:37.022 +00:00');
Unhandled rejection SequelizeUniqueConstraintError: Validation error
at Query.formatError (/home/ohnobinki/public_html/turbocase1/node_modules/sequelize/lib/dialects/sqlite/query.js:231:14)
at Statement.<anonymous> (/home/ohnobinki/public_html/turbocase1/node_modules/sequelize/lib/dialects/sqlite/query.js:47:29)
at Statement.replacement (/home/ohnobinki/public_html/turbocase1/node_modules/sqlite3/lib/trace.js:20:31)
It seems that specifying {include: [User]} instructs Sequelize to create a new User instance matching the contents of user. That is not my goal. In fact, I find it hard to believe that such behaviour would ever be useful—I at least have no use for it. I want to be able to have a long-living User record in the database and at arbitrary times create new Things which refer to the User. In my shown example, I wait for the User to be created, but in actual code it would likely have been freshly loaded through User.findOne().
I have seen other questions and answers say that I have to explicitly specify the implicitly-created UserId column in my Thing.create() call. When Sequelize provides an API like Thing.belongsTo(User), I shouldn’t have to be aware of the fact that a Thing.UserId field is created. So what is the clean API-respecting way of creating a new Thing which refers to a particular User without having to guess the name of the UserId field? When I load a Thing and specify {include: [User]}, I access the loaded user through the thing.User property. I don’t think I’m supposed to know about or try to access a thing.UserId field. In my Thing.belongsTo(User) call, I never specify UserId, I just treat that like an implementation detail I shouldn’t care about. How can I continue to avoid caring about that implementation detail when creating a Thing?
The Thing.create() call that works but looks wrong to me:
Thing.create({
name: 'A thing',
UserId: user.id
});
Option 1 - risks DB inconsistency
Sequelize dynamically generates methods for setting associations on instances, e.g. thing.setUser(user);. In your use case:
sequelize.sync({force: true})
.then(function () {
return Promise.all([
User.create({email: 'asdf#example.org'}),
Thing.create({name: 'A thing'})
]);
})
.spread(function(user, thing) {
return thing.setUser(user);
})
.then(function(thing) {
console.log(JSON.stringify(thing));
});
Option 2 - does not work/buggy
It isn't documented, but from a code dive I think the following should work. It doesn't but that seems to be because of a couple of bugs:
// ...
.then(function () {
return models.User.create({email: 'asdf#example.org'});
})
.then(function(user) {
// Fails with SequelizeUniqueConstraintError - the User instance inherits isNewRecord from the Thing instance, but it has already been saved
return models.Thing.create({
name: 'thingthing',
User: user
}, {
include: [{
model: models.User
}],
fields: ['name'] // seems nec to specify all non-included fields because of line 277 in instance.js - another bug?
});
})
Replacing models.User.create with models.User.build doesn't work because the built but not saved instance's primary key is null. Instance#_setInclude ignores the instance if its primary key is null.
Option 3
Wrapping the Thing's create in a transaction prevents an inconsistent state.
sq.sync({ force: true })
.then(models.User.create.bind(models.User, { email: 'asdf#example.org' }))
.then(function(user) {
return sq.transaction(function(tr) {
return models.Thing.create({name: 'A thing'})
.then(function(thing) { return thing.setUser(user); });
});
})
.then(print_result.bind(null, 'Thing with User...'))
.catch(swallow_rejected_promise.bind(null, 'main promise chain'))
.finally(function() {
return sq.close();
});
I have uploaded a script demo'ing option 2 and option 3 here
Tested on sequelize#6.5.1 sqlite3#5.0.2 I can use User.associations.Comments.foreignKey as in:
const Comment = sequelize.define('Comment', {
body: { type: DataTypes.STRING },
});
const User = sequelize.define('User', {
name: { type: DataTypes.STRING },
});
User.hasMany(Comment)
Comment.belongsTo(User)
console.dir(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', [User.associations.Comments.foreignKey]: u0.id});
The association is also returned during creation, so you could also:
const Comments = User.hasMany(Comment)
await Comment.create({body: 'u0c0', [Comments.foreignKey]: u0.id});
and on many-to-many through tables you get foreignKey and otherKey for the second foreign key.
User.associations.Comments.foreignKey contains the foreignKey UserId.
Or analogously with aliases:
User.hasMany(Post, {as: 'authoredPosts', foreignKey: 'authorId'});
Post.belongsTo(User, {as: 'author', foreignKey: 'authorId'});
User.hasMany(Post, {as: 'reviewedPosts', foreignKey: 'reviewerId'});
Post.belongsTo(User, {as: 'reviewer', foreignKey: 'reviewerId'});
await sequelize.sync({force: true});
// Create data.
const users = await User.bulkCreate([
{name: 'user0'},
{name: 'user1'},
])
const posts = await Post.bulkCreate([
{body: 'body00', authorId: users[0].id, reviewerId: users[0].id},
{body: 'body01', [User.associations.authoredPosts.foreignKey]: users[0].id,
[User.associations.reviewedPosts.foreignKey]: users[1].id},
])
But that syntax is so long that I'm tempted to just hardcode the keys everywhere.
In MVC peoples are using join query to join the two different tables, but In sails.js what I have to use? There is any method in waterline?
The answer based on database you are using.
For instance, you need to populate values in Mongo not to join. Or you need to join tables if you are using MySQL or similar.
In a nutshell, all this stuff is covered via Waterline. So you can just declare model in api/models with associations. Joining and populating is executing under the Waterline adapter.
For instance, you have User and Comment.
// api/models/User.js
module.exports = {
attributes: {
name: {
type: 'string'
},
comments: {
collection: 'Comment',
via: 'user'
}
}
};
// api/models/Comment.js
module.exports = {
attributes: {
text: {
type: 'string'
},
user: {
model: 'User',
via: 'comments'
}
}
};
Then you are execute User.find() and get already joined\populated tables from database.
But, if you want to execute manual joining, you can use .populate() method on Model instance. For instance:
// api/controllers/AnyController.js
module.exports = {
action: function(req, res) {
User
.findOne('ID_HERE')
.populate('comments')
.then(function(result) {})
.catch(function(error) {});
}
};
You can read more about populate here - http://sailsjs.org/documentation/reference/waterline-orm/queries/populate
Using Sequelize, I've created two models: User and Login.
Users can have more than one Login, but a login must have exactly one user, which means a Login cannot be saved without a User ID.
How do I .create a Login with a User association all in one swoop?
Current Code (Doesn't Work)
// Set up the models
var User = sequelize.define('User', {});
var Login = sequelize.define('Login', {});
Login.belongsTo(User, {
onDelete: 'cascade',
foreignKey: {
field: 'userId',
allowNull: false,
}
});
// Create the instances
var user = User.create().then(function() {
// THIS IS WHERE I WOULD LIKE TO SET THE ASSOCIATION
var login = Login.create({
userId: user.get('id')
});
)};
The above results in SequelizeValidationError: notNull Violation: UserId cannot be null
Assuming you have the right association between users and login,
you can just create a user including a login:
User.create({
name: "name",
Login: {...}
},{
include: Login
})
you can find more information here:
https://sequelize.org/docs/v6/advanced-association-concepts/creating-with-associations/
First of all you need to setup the relations in both ways, like this:
// Set up the models
var User = sequelize.define('User', {});
var Login = sequelize.define('Login', {});
// Set the correct associations
User.hasMany(Login, {})
Login.belongsTo(User, {});
Then, you need to properly get the instances returned by the promises:
// Create the instances
User.create({}).then(function(newUser) {
// now you can use newUser acessors to create the login
return newUser.createLogin({});
).then(function(newLogin){
// newLogin
}).catch(function(error){
// error
});
In your .then, the callback receives the model instance created by the previous call. You need to specify the argument inside the callback function.
var user = User.create().then(function(user) {
// THIS IS WHERE I WOULD LIKE TO SET THE ASSOCIATION
var login = Login.create({
userId: user.get('id')
});
return login
}).then(function(login) {
// all creation are complete. do something.
});
Also something important I would like to point out is your missing var statements! Those are important but not related to this question. See Declaring variables without var keyword
An Update to #Arwed Mett's answer
//Create Association Alias or just setting association alias by using 'as' keyword will also work
Login.User = Login.belongsTo(User);
User.create({
name: "name",
Login: {...}
}, {
include: [{
association: Login.User
}]
});
Refrence link - http://docs.sequelizejs.com/manual/tutorial/associations.html#creating-with-associations
For those like me who were trying to create an instance of a model including another instance, like:
var login1 = await Login.create(...);
var user1 = await User.create({
Login: login1
}, {
include: Login
});
You can't because this method is used to embed an instance (Login) which is not already existing and that will be created at the parent instance (User) creation level.
So, if you want to embed an already existing Login in the newly created User, do instead:
var login1 = await Login.create(...);
var user1 = await User.create({
loginId: login1.get('id')
}, {});
You have association between User an Login with constraint allowNull at false. You must create Login before User or set allowNull at true in model and the table to DB (LoginId Null constraint)
var User = sequelize.define('User', {});
var Login = sequelize.define('Login', {});
Login.belongsTo(User, {
onDelete: 'cascade',
foreignKey: {
field: 'userId',
allowNull: false,
}
});
Solution
Login.create({
username: "username",
User: {...}
},{
include: User
})
I have the same issue recently!
I have a typo mistake with the foreignKey config. Use field instead of name caused the issue.
The change below will fix it.
{
foreignKey: {
name: 'userId',
allowNull: false,
}
}
As an extra you could also nest your creation to be even more effective and concise.
// Set up the models
var User = sequelize.define('User', {});
var Login = sequelize.define('Login', {});
...
User.create({
name: "name",
Login:
{
users: {..i.e several users if a user belongs to another user..}
}
},{
include:{
model: Login,
include: User //nested model.Create
}
})
as seen here: https://github.com/sequelize/sequelize/issues/7252
I'm trying to create a HABTM relationship with Sequelize but I can't get it done.... I still receive an error message:
return (tableName1.toLowerCase() < tableName2.toLowerCase()) ? (tableName1
^
TypeError: Cannot call method 'toLowerCase' of undefined
I have a User model, a Book model and an UserBooks model. And ofcourse my database contains a "users" table, "user_books" table and "books" table.
UserBooks model:
module.exports = function(schema, DataTypes) {
var UserBooks = schema.define('UserBooks', {
}, {
tableName: 'user_books', // this will define the table's name
timestamps: false // this will deactivate the timestamp columns
});
UserBooks.sync();
return UserBooks;
};
User model:
module.exports = function(schema, DataTypes) {
var User = schema.define('User', {
keywords: DataTypes.STRING
}, {
tableName: 'users', // this will define the table's name
timestamps: false ,// this will deactivate the timestamp columns
syncOnAssociation:false
});
User.hasMany(Book, { foreignKey: 'user_id', through: UserBooks });
User.sync();
return User;
};
Book model:
module.exports = function(schema, DataTypes) {
var Book = schema.define('Book', {
keywords: DataTypes.STRING
}, {
tableName: 'books', // this will define the table's name
timestamps: false ,// this will deactivate the timestamp columns
syncOnAssociation:false
});
Book.hasMany(User, { foreignKey: 'book_id', through: UserBooks });
Book.sync();
return Book;
};
In your User model you are trying to create an association with a model that is not defined in that scope. In User.js, you only have access to User, not Book or UserBooks which are undefined. Thats whats causing your error.
You can either create associations in the place where you import all your models into your app, or in the models file by importing the models you want to associate with (bevare of circular imports). Your user model could be changed to:
module.exports = function(schema, DataTypes) {
var Book = schema.import(__dirname + '/book');
var UserBooks = schema.import(__dirname + '/userbooks');
var User = schema.define('User', {
keywords: DataTypes.STRING
}, {
tableName: 'users', // this will define the table's name
timestamps: false ,// this will deactivate the timestamp columns
syncOnAssociation:false
});
User.hasMany(Book, { foreignKey: 'user_id', through: UserBooks });
Book.hasMany(User, { foreignKey: 'book_id', through: UserBooks });
return User;
};
For another example of how to do it, see http://sequelizejs.com/articles/express#minimal-express-app
Also, I've removed the call to User.sync from your code. Sync is an async call, while import is sync. This means that your are defining your model, starting to sync it to the DB, and then returning it, before you know that it has finished syncing. This means you could potentially be trying to work create instances with it before the table has been created. Instead, you should use sequelize.sync to sync all your models at once, and attach a callback to wait for the sync to finish (see the link I posted for a code example)