I've breaking my head over this sequelize to get the products questions and also to include its answers as well
const ProductQuestions = sequelize.define('product_questions', {
user: {
type: Sequelize.BIGINT
},
product: {
type: Sequelize.BIGINT
},
question: {
type: Sequelize.TEXT
}
});
ProductQuestions.associate = function(models) {
ProductQuestion.hasMany(models.product_answers,{
foreignKey: 'question',
as: 'questionId'
});
}
const ProductAnswer = sequelize.define('product_answers', {
question: {
type: Sequelize.BIGINT,
field: 'questionId'
},
answer: {
type: Sequelize.TEXT
},
user: {
type: Sequelize.BIGINT,
field: 'userId'
}
});
ProductQuestiosn.findAll({include: ['product_answers']});
for some reason when I that, the columns is wrong when the query runs
SELECT
"product_questions".*,
"product_answers"."id" AS "product_answers.id",
"product_answers"."questionId" AS "product_answers.questionId",
"product_answers"."answer" AS "product_answers.answer",
"product_answers"."userId" AS "product_answers.user",
"product_answers"."productQuestionId" AS "product_answers.productQuestionId"
FROM (
SELECT
"product_questions"."id",
"product_questions"."productId" AS "product",
"product_questions"."question",
"product_questions"."userId" AS "user",
FROM
"product_questions" AS "product_questions")
AS "product_questions"
LEFT OUTER JOIN "product_answers" AS "product_answers"
ON "product_questions"."id" = "product_answers"."productQuestionId"
not sure why is
ON "product_questions"."id" = "product_answers"."productQuestionId"
when it should be
ON "product_questions"."id" = "product_answers"."questionId"
thank you for your help
so i figured it out!
so it appears that I have to name my columns properly
for the product_answers table in my postgres database, I had the column questionId but it should be named productQuestionId. I guess it's for naming convention, i can't just name the foreign key the way i want.
Related
Using Sequelize, I'm trying to get an output like this:
[{
"Id": 1,
"Name": "Game 1",
"Teams": [{
"Id": 1,
"Name": "Team 1",
"Users": [{
"Id": 1,
"UserName": "User 1"
}]
}]
}, {
"Id": 2,
"Name": "Game 2",
"Teams": [{
"Id": 1,
"Name": "Team 1",
"Users": [{
"Id": 2,
"UserName": "User 2"
}]
}]
}]
Note that Team 1 has 2 different users, but that's only because they're set up that way per game... so a user isn't tied directly to a team, but rather through a team game constraint. Basically, my Game HasMany Teams, and my Game/Team HasMany Users... a many-to-many-to-many relationship. I was trying to follow this thread, but it seems like what they're doing there doesn't actually work, as I tried doing this:
// models/Game.js
module.exports = (sequelize, types) => {
const GameModel = sequelize.define('Game', {
Id: {
type: types.INTEGER,
primaryKey: true,
autoIncrement: true
},
Name: {
type: types.STRING,
allowNull: false
}
});
GameModel.associate = (models) => {
GameModel.belongsToMany(models.Team, {
as: 'Teams',
foreignKey: 'GameId',
through: models.GameTeam
});
};
return GameModel;
};
// models/Team.js
module.exports = (sequelize, types) => {
const TeamModel = sequelize.define('Team', {
Id: {
type: types.INTEGER,
primaryKey: true,
autoIncrement: true
},
Name: {
type: types.STRING,
allowNull: false
}
});
TeamModel.associate = (models) => {
TeamModel.belongsToMany(models.Game, {
as: 'Games',
foreignKey: 'TeamId',
through: models.GameTeam
});
};
return TeamModel;
};
// models/User.js
module.exports = (sequelize, types) => {
const UserModel = sequelize.define('User', {
Id: {
type: types.INTEGER,
primaryKey: true,
autoIncrement: true
},
UserName: {
type: types.STRING,
allowNull: false
}
});
return UserModel;
};
// models/GameTeam.js
module.exports = (sequelize, types) => {
const GameTeamModel = sequelize.define('GameTeam', {
Id: {
type: types.INTEGER,
primaryKey: true,
autoIncrement: true
}
});
GameTeamModel.associate = (models) => {
GameTeamModel.belongsToMany(models.User, {
as: 'Users',
through: 'GameTeamUser'
});
};
return GameTeamModel;
};
The above models create the tables just fine, with what appears to be the appropriate columns. I then do some inserts and try to use a findAll on the Game model like this:
GameModel.findAll({
include: [{
association: GameModel.associations.Teams,
include: [{
association: GameTeamModel.associations.Users,
through: {
attributes: []
}
}],
through: {
attributes: []
}
}]
});
The query starts to go wrong at the 2nd include with the association of the Users. Because I'm trying to nest the users inside of the teams, I figured the join would attempt to use the unique ID on the through table (GameTeams.Id), but instead, the query ends up using this:
LEFT OUTER JOIN `GameTeamUser` AS `Teams->Users->GameTeamUser` ON `Teams`.`Id` = `Teams->Users->GameTeamUser`.`GameTeamId`
I figured the ON would be GameTeams.Id = Teams->Users->GameTeamuser.GameTeamId, but I don't know why it's not, and how to adjust it... I've tried using a custom on in my include (per the docs), but it seems to be ignored completely. Anyone have any advice? Or possibly a better way of structuring this, so it works the way I want it to?
I think you are overcomplicating this thinking you have a many to many to many..and i can see that the fields for your model for GameTeam do not match up with the foreign keys you have declared in your other models...
What do your database tables look like?
Am i correct in saying, that a game has many teams, and a team has many users... however a user can only be on one team at a time, and a team is only in one game at a time? (i am assuming the game/team join and the team/user join are simply temporary records in the join tables disappearing after the game is over etc)
I'm trying to make joined queries with Sequelize.
That's my db :
What I need is to select all of my relations and get this kind of result:
[
{
id: 1,
State: true,
FK_User: {
id: 2,
Name: "my name"
},
FK_Team: {
id: 3,
Name: "team name"
}
},
...
]
But today I've got this result:
[
{
id: 1,
State: true,
FK_User: 2,
FK_Team: 3
},
...
]
For each of my relations, I've go to do another request to get datas ...
So I putted a look in this Stack and in the doc.
Then I made this code :
let User = this.instance.define("User", {
Name: {
type: this.libraries.orm.STRING,
allowNull: false
}
});
let Team = this.instance.define("Team", {
Name: {
type: this.libraries.orm.STRING,
allowNull: false
}
});
let Relation = this.instance.define("Relation", {
State: {
type: this.libraries.orm.BOOLEAN,
allowNull: false,
defaultValue: 0
}
});
Relation.hasOne(User, {as: "FK_User", foreignKey: "id"});
Relation.hasOne(Team, {as: "FK_Team", foreignKey: "id"});
With this code, I haven't got any relation between tables... So I added theses two lines. I don't understand why I need to make a two direction relation, because I don't need to access Relation From User and Team ...
User.belongsTo(Relation, {foreignKey: 'FK_User_id'});
Team.belongsTo(Relation, {foreignKey: 'FK_Team_id'});
When I do that, I've a FK_User_id in the User table and a FK_Team_id in the Team table ... I don't know how to make this simple relation and get all I need with my futur request and the include: [User, Team]} line.
User.hasOne(Relation);
Team.hasOne(Relation);
Relation.belongsTo(Team);
Relation.belongsTo(User);
This code seems to work.
I don't know why ...
Here your associations are setup correctly you can join it with include :
Relation.findAll({
where : {
state : true
}
include:[
{
model : User
},
{
model : Team
}
]
})
I am looking to return all articles from the database associated with one or more keywords, but I am not sure there right way to go about this?
I am using Sequelize 3.x, with node.js 3.7.0.
The data model looks at follows:
const Article = sequelize.define('article', {
...
}
const Keyword = sequelize.define('keyword', {
name: Sequelize.STRING,
lang: Sequelize.STRING
}
const ArticleKeyword = sequelize.define('article_keyword', {
articleId: Sequelize.INTEGER,
keywordId: Sequelize.INTEGER
}
(Article).belongsToMany(
Keyword, { through: ArticleKeyword, as: 'keyword' });
(Keyword).belongsToMany(
Article { through: ArticleKeyword, as: 'article' });
Then the query I tried:
var keywordFilter;
if (req.body.keywords) {
var keywords = req.body.keywords);
if (typeof keywords === 'string') {
keywords = keywords.split(/ *, */);
}
keywordFilter = { name: { $in: keywords } };
}
Article.findAll({
where: {
deleted: false
},
include: [{
model: Keyword,
as: 'keywords',
where: keywordFilter,
attributes: ['name'],
through: {
attributes: []
}
}]
}).then(function(articles) {
...
});
The issue I am finding here is rather than selecting just the articles with the matching keywords it returns all the articles and then simply selects the keywords specified in the query for the results.
Can anyone suggest the right way to go about this?
Hi can you try passing
require:true
in the include block for inner join and check
Ref : https://stackoverflow.com/a/31680398/4583460
I have two Schema defined as below:
var WorksnapsTimeEntry = BaseSchema.extend({
student: {
type: Schema.ObjectId,
ref: 'Student'
},
timeEntries: {
type: Object
}
});
var StudentSchema = BaseSchema.extend({
firstName: {
type: String,
trim: true,
default: ''
// validate: [validateLocalStrategyProperty, 'Please fill in your first name']
},
lastName: {
type: String,
trim: true,
default: ''
// validate: [validateLocalStrategyProperty, 'Please fill in your last name']
},
displayName: {
type: String,
trim: true
},
municipality: {
type: String
}
});
And I would like to loop thru each student and show it's time entries. So far I have this code which is obviously not right as I still dont know how do I join WorksnapTimeEntry schema table.
Student.find({ status: 'student' })
.populate('student')
.exec(function (err, students) {
if (err) {
return res.status(400).send({
message: errorHandler.getErrorMessage(err)
});
}
_.forEach(students, function (student) {
// show student with his time entries....
});
res.json(students);
});
Any one knows how do I achieve such thing?
As of version 3.2, you can use $lookup in aggregation pipeline to perform left outer join.
Student.aggregate([{
$lookup: {
from: "worksnapsTimeEntries", // collection name in db
localField: "_id",
foreignField: "student",
as: "worksnapsTimeEntries"
}
}]).exec(function(err, students) {
// students contain WorksnapsTimeEntries
});
You don't want .populate() here but instead you want two queries, where the first matches the Student objects to get the _id values, and the second will use $in to match the respective WorksnapsTimeEntry items for those "students".
Using async.waterfall just to avoid some indentation creep:
async.waterfall(
[
function(callback) {
Student.find({ "status": "student" },{ "_id": 1 },callback);
},
function(students,callback) {
WorksnapsTimeEntry.find({
"student": { "$in": students.map(function(el) {
return el._id
})
},callback);
}
],
function(err,results) {
if (err) {
// do something
} else {
// results are the matching entries
}
}
)
If you really must, then you can .populate("student") on the second query to get populated items from the other table.
The reverse case is to query on WorksnapsTimeEntry and return "everything", then filter out any null results from .populate() with a "match" query option:
WorksnapsTimeEntry.find().populate({
"path": "student",
"match": { "status": "student" }
}).exec(function(err,entries) {
// Now client side filter un-matched results
entries = entries.filter(function(entry) {
return entry.student != null;
});
// Anything not populated by the query condition is now removed
});
So that is not a desirable action, since the "database" is not filtering what is likely the bulk of results.
Unless you have a good reason not to do so, then you probably "should" be "embedding" the data instead. That way the properties like "status" are already available on the collection and additional queries are not required.
If you are using a NoSQL solution like MongoDB you should be embracing it's concepts, rather than sticking to relational design principles. If you are consistently modelling relationally, then you might as well use a relational database, since you won't be getting any benefit from the solution that has other ways to handle that.
It is late but will help many developers.
Verified with
"mongodb": "^3.6.2",
"mongoose": "^5.10.8",
Join two collections in mongoose
ProductModel.find({} , (err,records)=>{
if(records)
//reurn records
else
// throw new Error('xyz')
})
.populate('category','name') //select only category name joined collection
//.populate('category') // Select all detail
.skip(0).limit(20)
//.sort(createdAt : '-1')
.exec()
ProductModel Schema
const CustomSchema = new Schema({
category:{
type: Schema.ObjectId,
ref: 'Category'
},
...
}, {timestamps:true}, {collection: 'products'});
module.exports = model('Product',CustomSchema)
Category model schema
const CustomSchema = new Schema({
name: { type: String, required:true },
...
}, {collection: 'categories'});
module.exports = model('Category',CustomSchema)
Suppose i have two models
var A = db.seq.define('A',{
id1: { type: db.Sequelize.INTEGER},
id2: { type: db.Sequelize.INTEGER},
count: { type: db.Sequelize.INTEGER},
});
var b = db.seq.define("b",{
id1: { type: db.Sequelize.INTEGER },
id2: { type: db.Sequelize.INTEGER },
name: { type: db.Sequelize.STRING},
});
A.hasMany(B, {foreignKey: 'id1'})
B.belongsTo(A, {foreignKey: 'id1'})
A.findAll({
include: [{
model: B,
where: { B.id2: { $eq:A.id2 } }
}]
})
Its possible to make that kind of query?
How can i update my model to specify some other condition on the join sentence or should i move the check to the query where clause?
Some example will be really helpful
Thanks
Try
A.findAll({
include: [{
model: B,
where: { id2: sequelize.col('A.id2') }
}]
})
id2 will automatically reference B.
Currently Jan Aagaard Meier's answer is not fully working
I have found out that id2 is not recognized in the actual query.
For example the query
A.findAll({
include: [{
model: B,
where: { id2: sequelize.col('A.id2') }
}]
})
should recognize as inner join on 'A'.'PrimaryKey' = 'B'.'ForeignKey' and id2 = 'A'.'id2'
but somehow sequelize does not add up the left side so it ignores as
'A'.'PrimaryKey' = 'B'.'ForeignKey' and 'A'.'id2'
so query is not working
I've done the raw query that is printed when sequelize is executed and found out what was wrong.
Does anyone have an idea to solve this?
found the answer
A.findAll({
include: [{
model: B,
where: { sequelize.col('A.id2), "=", sequelize.col('B.id2') }
}]
})
This works fine for me. Hope this works well for you