The Sequelize documentation is very limited when it comes to querying relations:
For example, I would like to query all Projects with no Tasks that have a state OR description defined (therefore, either these projects have no tasks at all, or they only have tasks that have only a state or only a description, but not both).
You might think something like this would work:
Project.findAll({
include: [{
model: Task,
where: {
$or: {
state: null,
description: null
}
}
}]
});
However, this doesn't work because it wouldn't return any Projects that have no tasks at all.
Related
I'm trying to update a one to many relationship in Prisma. My schema looks like this
model A_User {
id Int #id
username String
age Int
bio String #db.VarChar(1000)
createdOn DateTime #default(now())
features A_Features[]
}
model A_Features {
id Int #id #default(autoincrement())
description String
A_User A_User? #relation(fields: [a_UserId], references: [id])
a_UserId Int?
}
I'm trying to add a couple of new features to user with id: 1, or update them if they are already there.
I'm trying doing something like
const post = await prisma.a_User.update({
where: { id: 1},
data: {
features: {
upsert: [
{ description: 'first feature'},
{ description: 'second feature'}
]
}
}
})
The compiler isn't happy, it tells me
Type '{ features: { upsert: { description: string; }[]; }; }' is not assignable to type '(Without<A_UserUpdateInput, A_UserUncheckedUpdateInput> & A_UserUncheckedUpdateInput) | (Without<...> & A_UserUpdateInput)'.
Object literal may only specify known properties, and 'features' does not exist in type '(Without<A_UserUpdateInput, A_UserUncheckedUpdateInput> & A_UserUncheckedUpdateInput) | (Without<...> & A_UserUpdateInput)'.ts(2322)
index.d.ts(1572, 5): The expected type comes from property 'data' which is declared here on type '{ select?: A_UserSelect; include?: A_UserInclude; data: (Without<A_UserUpdateInput, A_UserUncheckedUpdateInput> & A_UserUncheckedUpdateInput) | (Without<...> & A_UserUpdateInput); where: A_UserWhereUniqueInput; }'
(property) features: {
upsert: {
description: string;
}[];
}
I can't work out how to do it nor I can find clear help in the documentation. Any idea on how to implement it or where I can find some examples?
I'm providing my solution based on the clarifications you provided in the comments. First I would make the following changes to your Schema.
Changing the schema
model A_User {
id Int #id
username String
age Int
bio String #db.VarChar(1000)
createdOn DateTime #default(now())
features A_Features[]
}
model A_Features {
id Int #id #default(autoincrement())
description String #unique
users A_User[]
}
Notably, the relationship between A_User and A_Features is now many-to-many. So a single A_Features record can be connected to many A_User records (as well as the opposite).
Additionally, A_Features.description is now unique, so it's possible to uniquely search for a certain feature using just it's description.
You can read the Prisma Guide on Relations to learn more about many-to-many relations.
Writing the update query
Again, based on the clarification you provided in the comments, the update operation will do the following:
Overwrite existing features in a A_User record. So any previous features will be disconnected and replaced with the newly provided ones. Note that the previous features will not be deleted from A_Features table, but they will simply be disconnected from the A_User.features relation.
Create the newly provided features that do not yet exist in the A_Features table, and Connect the provided features that already exist in the A_Features table.
You can perform this operation using two separate update queries. The first update will Disconnect all previously connected features for the provided A_User. The second query will Connect or Create the newly provided features in the A_Features table. Finally, you can use the transactions API to ensure that both operations happen in order and together. The transactions API will ensure that if there is an error in any one of the two updates, then both will fail and be rolled back by the database.
//inside async function
const disconnectPreviouslyConnectedFeatures = prisma.a_User.update({
where: {id: 1},
data: {
features: {
set: [] // disconnecting all previous features
}
}
})
const connectOrCreateNewFeatures = prisma.a_User.update({
where: {id: 1},
data: {
features: {
// connect or create the new features
connectOrCreate: [
{
where: {
description: "'first feature'"
}, create: {
description: "'first feature'"
}
},
{
where: {
description: "second feature"
}, create: {
description: "second feature"
}
}
]
}
}
})
// transaction to ensure either BOTH operations happen or NONE of them happen.
await prisma.$transaction([disconnectPreviouslyConnectedFeatures, connectOrCreateNewFeatures ])
If you want a better idea of how connect, disconnect and connectOrCreate works, read the Nested Writes section of the Prisma Relation queries article in the docs.
The TypeScript definitions of prisma.a_User.update can tell you exactly what options it takes. That will tell you why the 'features' does not exist in type error is occurring. I imagine the object you're passing to data takes a different set of options than you are specifying; if you can inspect the TypeScript types, Prisma will tell you exactly what options are available.
If you're trying to add new features, and update specific ones, you would need to specify how Prisma can find an old feature (if it exists) to update that one. Upsert won't work in the way that you're currently using it; you need to provide some kind of identifier to the upsert call in order to figure out if the feature you're adding already exists.
https://www.prisma.io/docs/reference/api-reference/prisma-client-reference/#upsert
You need at least create (what data to pass if the feature does NOT exist), update (what data to pass if the feature DOES exist), and where (how Prisma can find the feature that you want to update or create.)
You also need to call upsert multiple times; one for each feature you're looking to update or create. You can batch the calls together with Promise.all in that case.
const upsertFeature1Promise = prisma.a_User.update({
data: {
// upsert call goes here, with "create", "update", and "where"
}
});
const upsertFeature2Promise = prisma.a_User.update({
data: {
// upsert call goes here, with "create", "update", and "where"
}
});
const [results1, results2] = await Promise.all([
upsertFeaturePromise1,
upsertFeaturePromise2
]);
I have the following scenario, my application has two entities: box and items with N to N relationship. I am using sequelize with MySQL.
I am using pseudocode to represent the tables:
Box {
id: Integer primary key
name: String
}
Item {
id: Integer primary key
name: String
}
I have set up the schemas with relations hasMany in both directions using the following through relation:
Box.hasMany(Item, { through: Box_Item });
Item.hasMany(Box, { through: Box_Item });
Box_Item {
id_box: Integer,
id_item: Integer,
item_order: Integer
}
With primary_key(id_box, id_item).
I tested it and I can call myBox.getItems() on my instance object myBox and easily get all the items it has.
I can make calls as
BoxModel.findOne({
where: { id: 1 },
include: [{ model: ItemModel }]
});
And it automatically understands there is a relation between the models through Box_Item and get everything correctly, except that I'm not getting the results sorted by item_order field. This field is a number from 1 to N that represents the item order inside that box.
I tried
BoxModel.findOne({
where: { id: 1 },
include: [
{
model: ItemModel,
order: 'item_order'
}
]
});
But it seems sequelizejs does not support order inside include yet (checked on their github repo).
I tried to force
BoxModel.findOne({
where: { id: 1 },
order: '`box_model`.`item_order`'
include: [ { model: ItemModel } ]
})
looking through the query sequelize creates but it just put the ORDER BY in two different places (inside INNER JOIN and at the end of the query, don't know why...) and I got an error.
So I searched for this on stackoverflow (1), found a few questions but I don't get a good way for doing that using the ORM.
How could I get the items sorted by item_order field when asking for specific box items?
After a few days trying to get it done I found an answer on stackoverflow that helped me.
After creating the relationships between Box and Item I can easily call on an instance:
myBox.getItems({
order: '`box_model`.`item_order`'
});
And then I get the result I'm expecting. But I had to look through the query sequelize is creating based on the models and get the correct field based on their renaming rules.
If you want you can pass the as parameter and rename your tables.
So, I'm using sequelize with a mysql instance and I have this hierarchy : a task has n images and also n metadata key value pairs.
I want to get all images based on userId column of task, and afterwards get them grouped by 'createdAt' column taking into consideration the day, since a normal groupby will be pointless ( no objects share the same datetime ). I did lots of test to try to group, and I ended up using this query, which gives bad results ( I have like 11 images for a task, and it retrieves 4 ). Honestly, i don't know what I'm doing wrong. Any of you have any idea?
This is the code snippet:
var userId = security.utils.getKeycloakSubject(req);
var where = {
userId: userId
};
db.image.findAll({
include: [{
model: db.task,
include: [{
model: db.metadata,
as: 'metadata'
}],
where: where
}],
group: [db.Sequelize.fn('DAY', db.Sequelize.col('image.createdAt'))]
}).then(function (images) {
return res.json(images);
}, function (error) {
return res.status(500).json(error);
})
I saw your question and also found this: Sequelize grouping by date, disregarding hours/minutes/seconds
It is a question about group the DAY(createdAt), looks similar with yours.
And my solution of GROUP BY DAY() is look like:
item.findAll({
attributes:
[[sequelize.fn('DATE_FORMAT', sequelize.col('TimeStamp'), '%H'), 'dates']],
group: [sequelize.fn('DAY', sequelize.col('TimeStamp'))]
}).
then(function(result){console.log(result)
}).
catch(function(error){}).catch(function(error) {
console.log(error);
});
So the raw SQL likes: SELECT DATE_FORMAT('TimeStamp', '%H') as 'dates' FROM tableName GROUP BY DAY('TimeStamp');
Hope it helps you, or you can show us the SQL you want to use, maybe it is easier to help you too.
Good luck.
I have a query I'm trying to perform based on a one to many relationship.
As an example there is a model called Users and one called Projects.
Users hasMany Projects
Projects have many types which are stored in a type (enum) column. There are 4 different types that potentially a user may have that I want to load. The catch is I want to include the most recent project record (createdAt column) for all networks that potentially will be there. I have not found a way to structure the query for it to work as an include. I have however found a way to do a raw query which does what I want.
I am looking for a way without having to do a raw query. By doing the raw query I have to map the returned results to users I've returned from the other method, or I have to do a simple include and then trim off all the results that are not the most recent. The latter is fine, but I see this getting slower as a user will have many projects and it will keep growing steadily.
This allow serialize a json for anywhere action about a model. Read it, very well
sequelize-virtual-fields
// define models
var Person = sequelize.define('Person', { name: Sequelize.STRING });
var Task = sequelize.define('Task', {
name: Sequelize.STRING,
nameWithPerson: {
type: Sequelize.VIRTUAL,
get: function() { return this.name + ' (' + this.Person.name + ')' }
attributes: [ 'name' ],
include: [ { model: Person, attributes: [ 'name' ] } ],
order: [ ['name'], [ Person, 'name' ] ]
}
});
// define associations
Task.belongsTo(Person);
Person.hasMany(Task);
// activate virtual fields functionality
sequelize.initVirtualFields();
Alright so I have a project in NodeJS where I'm utilizing Sequelize for a MySQL ORM. The thing works fantastically however I'm trying to figure out if there is a way to specify what fields are being returned on a query basis or if there's even a way just to do a .query() somewhere.
For example in our user database there can be ridiculous amounts of records and columns. In this case I need to return three columns only so it would be faster to get just those columns. However, Sequelize just queries the table for everything "*" to fulfill the full object model as much as possible. This is the functionality I'd like to bypass in this particular area of the application.
You have to specify the attributes as a property in the object that you pass to findAll():
Project.findAll({attributes: ['name', 'age']}).on('success', function (projects) {
console.log(projects);
});
How I found this:
The query is first called here: https://github.com/sdepold/sequelize/blob/master/lib/model-definition.js#L131
Then gets constructed here: https://github.com/sdepold/sequelize/blob/master/lib/connectors/mysql/query-generator.js#L56-59
Try this in new version
template.findAll({
where: {
user_id: req.params.user_id
},
attributes: ['id', 'template_name'],
}).then(function (list) {
res.status(200).json(list);
})
Use the arrays in the attribute key. You can do nested arrays for aliases.
Project.findAll({
attributes: ['id', ['name', 'project_name']],
where: {id: req.params.id}
})
.then(function(projects) {
res.json(projects);
})
Will yield:
SELECT id, name AS project_name FROM projects WHERE id = ...;
All Answers are correct but we can also use include and exclude as well
Model.findAll({
attributes: { include: ['id'] }
});
Model.findAll({
attributes: { exclude: ['createdAt'] }
});
Source