I have 2 tables tasks and groups with the association as
//Groups has many tasks
db.groups.hasMany(db.tasks, { as: "tasks" });
db.tasks.belongsTo(db.groups, {
foreignKey: "groupId",
as: "group",
});
I have tried this but no luck,
await Task.findAll({where: { userId: id },
include: [
{ model: db.groups, as: "groups" },
],
});
How can I retrieve groups from tasks using sequelize ? Simply, I want to fetch parent record from child using sequelize.
Thanks in advance.
You almost achieved your goal. Just correct an alias in include option:
await Task.findAll({where: { userId: id },
include: [
{ model: db.groups, as: "group" },
],
);
I currently have the following models in Sequelize:
Product
and
ProductList.belongsToMany(models.Product, { as: 'products', through:
sequelize.models.ProductListProduct, foreignKey: 'productListId'});
and the pivot, ProductListProduct
I am currently trying to get a series of productList to show on my homepage,
and would need to limit the returned products to a certain value (6 in this case):
let productLists = await ProductList.findAll({
where: {
slug: ['recommended', 'new_and_promos']
},
include: [{
model: Product,
as: 'products',
include: ['attributes', 'images'],
where: {
active: true
}
}],
order: [
[
'products', ProductListProduct, 'position', 'ASC'
]
]
})
This is the current fetch, however if I add a limit to the include, it tells me that only hasMany can have {separate: true} ;
To recap, what I'm trying to achieve is to return n ProductList, each with just m Product attached.
Managed to get it working like this, doesn't look ideal but it does the job:
let productLists = await ProductList.findAll({
where: {
slug: ['recommended', 'new_and_promos']
},
include: [{
model: Product,
as: 'products',
include: ['attributes', 'images'],
where: Sequelize.literal('`products->ProductListProduct`.`position` < 8')
}],
order: [
[
'products', ProductListProduct, 'position', 'ASC'
]
]
})
Context : I am having this problem were I am doing a query using sequilize an it only return's me an array with one position even though I have more than one field that correspond to the query.
This are my two involved models
This is my group.js model
module.exports = (sequelize, DataTypes) => {
const Group = sequelize.define('Group', {
name: DataTypes.STRING,
limit: DataTypes.STRING,
user_id: DataTypes.INTEGER
});
Group.associate = models => {
Group.belongsTo(models.User, { foreignKey: 'user_id' });
};
Group.associate = models => {
Group.hasMany(models.Movement, { foreignKey: 'group_id' });
};
return Group;
}
This is my movement.js model
module.exports = (sequelize, DataTypes) => {
const Mov = sequelize.define('Movement', {
description: DataTypes.STRING,
value: DataTypes.INTEGER,
group_id: DataTypes.INTEGER
});
Mov.associate = models => {
Mov.hasOne(models.Group, { foreignKey: 'group_id' });
};
return Mov;
}
This is my query (where you will see that I am doing an INNER JOIN to SUM the fields of the Movement table)
router.get('/', verify, async (req, res) => {
try {
const group = await Group.findAll({
attributes: [
'id',
'name',
'limit',
[sequelize.fn('SUM', sequelize.col('Movements.value')), 'total_spent'],
],
include: [{
attributes: [], // this is empty because I want to hide the Movement object in this query (if I want to show the object just remove this)
model: Movement,
required: true
}],
where: {
user_id: req.userId
}
});
if (group.length === 0) return res.status(400).json({ error: "This user has no groups" })
res.status(200).json({ groups: group }) //TODO see why this is onyl return one row
} catch (error) {
console.log(error)
res.status(400).json({ Error: "Error while fetching the groups" });
}
});
Problem is that it only return's one position of the expected array :
{
"groups": [
{
"id": 9,
"name": "rgrgrg",
"limit": 3454354,
"total_spent": "2533"
}
]
}
It should return 2 positions
{
"groups": [
{
"id": 9,
"name": "rgrgrg",
"limit": 3454354,
"total_spent": "2533"
},
{
"id": 9,
"name": "rgrgrg",
"limit": 3454354,
"total_spent": "2533"
}
]
}
This is the query sequilize is giving me:
SELECT `Group`.`id`, `Group`.`name`, `Group`.`limit`, SUM(`Movements`.`value`) AS `total_spent` FROM `Groups` AS `Group` INNER JOIN `Movements` AS `Movements` ON `Group`.`id` = `Movements`.`group_id` WHERE `Group`.`user_id` = 1;
I guess you need to add an appropriate group by clause as follows -
const group = await Group.findAll({
attributes: [
'id',
'name',
'limit',
[sequelize.fn('SUM', sequelize.col('Movements.value')), 'total_spent'],
],
include: [{
attributes: [], // this is empty because I want to hide the Movement object in this query (if I want to show the object just remove this)
model: Movement,
required: true
}],
where: {
user_id: req.userId
},
group: '`Movements`.`group_id`'
});
Many-to-many "through" table with multiple rows of identical foreign key pairs only returns one result?
I just ran into this bug and added this options to the main query:
{
raw: true,
plain: false,
nest: true
}
Then you just merge the query.
It's a workaround, but might help someone.
I have two tables, locations and sensors. Each entry in sensors has a foreign key pointing to locations. Using Sequelize, how do I get all entries from locations and total count of entries in sensors that are associated with each entry in locations?
Raw SQL:
SELECT
`locations`.*,
COUNT(`sensors`.`id`) AS `sensorCount`
FROM `locations`
JOIN `sensors` ON `sensors`.`location`=`locations`.`id`;
GROUP BY `locations`.`id`;
Models:
module.exports = function(sequelize, DataTypes) {
var Location = sequelize.define("Location", {
id: {
type: DataTypes.INTEGER.UNSIGNED,
primaryKey: true
},
name: DataTypes.STRING(255)
}, {
classMethods: {
associate: function(models) {
Location.hasMany(models.Sensor, {
foreignKey: "location"
});
}
}
});
return Location;
};
module.exports = function(sequelize, DataTypes) {
var Sensor = sequelize.define("Sensor", {
id: {
type: DataTypes.INTEGER.UNSIGNED,
primaryKey: true
},
name: DataTypes.STRING(255),
type: {
type: DataTypes.INTEGER.UNSIGNED,
references: {
model: "sensor_types",
key: "id"
}
},
location: {
type: DataTypes.INTEGER.UNSIGNED,
references: {
model: "locations",
key: "id"
}
}
}, {
classMethods: {
associate: function(models) {
Sensor.belongsTo(models.Location, {
foreignKey: "location"
});
Sensor.belongsTo(models.SensorType, {
foreignKey: "type"
});
}
}
});
return Sensor;
};
Use findAll() with include() and sequelize.fn() for the COUNT:
Location.findAll({
attributes: {
include: [[Sequelize.fn("COUNT", Sequelize.col("sensors.id")), "sensorCount"]]
},
include: [{
model: Sensor, attributes: []
}]
});
Or, you may need to add a group as well:
Location.findAll({
attributes: {
include: [[Sequelize.fn("COUNT", Sequelize.col("sensors.id")), "sensorCount"]]
},
include: [{
model: Sensor, attributes: []
}],
group: ['Location.id']
})
For Counting associated entries with Sequelize
Location.findAll({
attributes: {
include: [[Sequelize.fn('COUNT', Sequelize.col('sensors.location')), 'sensorCounts']]
}, // Sequelize.col() should contain a attribute which is referenced with parent table and whose rows needs to be counted
include: [{
model: Sensor, attributes: []
}],
group: ['sensors.location'] // groupBy is necessary else it will generate only 1 record with all rows count
})
Note :
Some how, this query generates a error like sensors.location is not exists in field list. This occur because of subQuery which is formed by above sequelize query.
So solution for this is to provide subQuery: false like example
Location.findAll({
subQuery: false,
attributes: {
include: [[Sequelize.fn('COUNT', Sequelize.col('sensors.location')), 'sensorCounts']]
},
include: [{
model: Sensor, attributes: []
}],
group: ['sensors.location']
})
Note:
**Sometime this could also generate a error bcz of mysql configuration which by default contains only-full-group-by in sqlMode, which needs to be removed for proper working.
The error will look like this..**
Error : Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'db.table.id' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
So to resolve this error follow this answer
SELECT list is not in GROUP BY clause and contains nonaggregated column .... incompatible with sql_mode=only_full_group_by
Now this will successfully generate all associated counts
Hope this will help you or somebody else!
Location.findAll({
attributes: {
include: [[Sequelize.fn("COUNT", Sequelize.col("sensors.id")), "sensorCount"]]
},
include: [{
model: Sensor, attributes: []
}]
});
and it works. but when i add "limit", i got error: sensors undefined
Example of HAVING, ORDER BY, INNER vs OUTER JOIN + several bugs/unintuitive behavior
I went into more detail at: Sequelize query with count in inner join but here's a quick summary list of points:
you must use row.get('count'), row.count does not work
you must parseInt on PostgreSQL
this code fails on PostgreSQL with column X must appear in the GROUP BY clause or be used in an aggregate function due to a sequelize bug
OUTER JOIN example which includes 0 counts by using required: false:
sqlite.js
const assert = require('assert');
const { DataTypes, Op, Sequelize } = require('sequelize');
const sequelize = new Sequelize('tmp', undefined, undefined, Object.assign({
dialect: 'sqlite',
storage: 'tmp.sqlite'
}));
;(async () => {
const User = sequelize.define('User', {
name: { type: DataTypes.STRING },
}, {});
const Post = sequelize.define('Post', {
body: { type: DataTypes.STRING },
}, {});
User.belongsToMany(Post, {through: 'UserLikesPost'});
Post.belongsToMany(User, {through: 'UserLikesPost'});
await sequelize.sync({force: true});
const user0 = await User.create({name: 'user0'})
const user1 = await User.create({name: 'user1'})
const user2 = await User.create({name: 'user2'})
const post0 = await Post.create({body: 'post0'})
const post1 = await Post.create({body: 'post1'})
const post2 = await Post.create({body: 'post2'})
// Set likes for each user.
await user0.addPosts([post0, post1])
await user1.addPosts([post0, post2])
let rows = await User.findAll({
attributes: [
'name',
[sequelize.fn('COUNT', sequelize.col('Posts.id')), 'count'],
],
include: [
{
model: Post,
attributes: [],
required: false,
through: {attributes: []},
where: { id: { [Op.ne]: post2.id }},
},
],
group: ['User.name'],
order: [[sequelize.col('count'), 'DESC']],
having: sequelize.where(sequelize.fn('COUNT', sequelize.col('Posts.id')), Op.lte, 1)
})
assert.strictEqual(rows[0].name, 'user1')
assert.strictEqual(parseInt(rows[0].get('count'), 10), 1)
assert.strictEqual(rows[1].name, 'user2')
assert.strictEqual(parseInt(rows[1].get('count'), 10), 0)
assert.strictEqual(rows.length, 2)
})().finally(() => { return sequelize.close() });
with:
package.json
{
"name": "tmp",
"private": true,
"version": "1.0.0",
"dependencies": {
"pg": "8.5.1",
"pg-hstore": "2.3.3",
"sequelize": "6.5.1",
"sqlite3": "5.0.2"
}
}
and Node v14.17.0.
INNER JOIN version excluding 0 counts:
let rows = await User.findAll({
attributes: [
'name',
[sequelize.fn('COUNT', '*'), 'count'],
],
include: [
{
model: Post,
attributes: [],
through: {attributes: []},
where: { id: { [Op.ne]: post2.id }},
},
],
group: ['User.name'],
order: [[sequelize.col('count'), 'DESC']],
having: sequelize.where(sequelize.fn('COUNT', '*'), Op.lte, 1)
})
assert.strictEqual(rows[0].name, 'user1')
assert.strictEqual(parseInt(rows[0].get('count'), 10), 1)
assert.strictEqual(rows.length, 1)
How about defining a database view for it and then a model for that view? You can just get the relationship to the view included in your query whenever you need the number of sensors. The code may look cleaner this way, but I'm not aware if there will be performance costs. Somebody else may answer that...
CREATE OR REPLACE VIEW view_location_sensors_count AS
select "locations".id as "locationId", count("sensors".id) as "locationSensorsCount"
from locations
left outer join sensors on sensors."locationId" = location.id
group by location.id
When defining the model for the view you remove the id attribute and set the locationId as the primary key.
Your model could look like this:
const { Model, DataTypes } = require('sequelize')
const attributes = {
locationID: {
type: DataTypes.UUIDV4, // Or whatever data type is your location ID
primaryKey: true,
unique: true
},
locationSensorsCount: DataTypes.INTEGER
}
const options = {
paranoid: false,
modelName: 'ViewLocationSensorsCount',
tableName: 'view_location_sensors_count',
timestamps: false
}
/**
* This is only a database view. It is not an actual table, so
* DO NOT ATTEMPT insert, update or delete statements on this model
*/
class ViewLocationSensorsCount extends Model {
static associate(models) {
ViewLocationSensorsCount.removeAttribute('id')
ViewLocationSensorsCount.belongsTo(models.Location, { as:'location', foreignKey: 'locationID' })
}
static init(sequelize) {
this.sequelize = sequelize
return super.init(attributes, {...options, sequelize})
}
}
module.exports = ViewLocationSensorsCount
In the end, in your Location model you set a hasOne relationship to the Sensor model.
Given the following sequelize models:
var User = db.define('user', {
name: Sequelize.STRING
});
var Group = db.define('group', {
name: Sequelize.STRING,
public : { type: Sequelize.BOOLEAN, defaultValue: true }
});
Group.belongsToMany(User, { as: 'specialUsers', through: 'user_groups', foreignKey: 'group_id' });
User.belongsToMany(Group, { through: 'user_groups', foreignKey: 'user_id' });
How would I go about finding the Groups for a through the Groups model where the Groups returned should be those where the user has a record in the many to many table -- or -- the group is a public group?
I've tried something like this:
return Group.findAll({
attributes: ['name', 'public'],
include: [{
model: User,
as: 'specialUsers',
where: {
$or : [
{name: 'Neill'},
Sequelize.literal('"group"."public" = true')
]
}
}]
});
return Group.findAll({
attributes: ['name', 'public'],
include: [{
model: User,
as: 'specialUsers',
}],
where: {
$or : {
'$users.name$": 'Neill',
public: true
}
}
});
Should work if you are on a fairly recent version. Note that I moved the where out of the include