In the Nest js create dto I receive two properties name and age. I need to validate if user with name and age already exists should trough 400 error "duplicate values".
Like in table we have name: "John", age: 20
and we create user with the same value/combination "John" and 20, it should show error.
I tried to use validation check NameExists but do not know how to take values for both, I only take for one.
https://dev.to/avantar/custom-validation-with-database-in-nestjs-gao
#IsNotEmpty({
message: 'Name is missing',
})
#MinLength(5, {
message: 'Name is too short. Select name longer than 5 characters.',
})
#UserExists()
name: string;
#IsNotEmpty({
message: 'Age is missing.',
})
#IsInt()
#Transform(({ value }) => Number(value))
age: number;
In this example, you could see how to access other properties of the object in your custom decorator.
https://github.com/typestack/class-validator#custom-validation-decorators
However, my choice, in this case, would be to create proper unique indexes in the database and handle the DB error as you could encounter race conditions if 2 requests will come with the same user name and age at the same time.
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 think I've done enough research on this subject and I've only got a headache.
Here is what I have done and understood: I have restructured my MySQL database so that I will keep my user's data in different tables, I am using foreign keys. Until now I only concluded that foreign keys are only used for consistency and control and they do not automatize or do anything else (for example, to insert data about the same user in two tables I need to use two separate insert statements and the foreign key will not help to make this different or automatic in some way).
Fine. Here is what I want to do: I want to use Sequelize to insert, update and retrieve data altogether from all the related tables at once and I have absolutely no idea on how to do that. For example, if a user registers, I want to be able to insert the data in the table "A" containing some user information and in the same task insert in the table B some other data (like the user's settings in the dedicated table or whatever). Same with retrievals, I want to be able to get an object (or array) with all the related data from different tables fitting in the criteria I want to find by.
Sequelize documentation covers the things in a way that every thing depends on the previous one, and Sequelize is pretty bloated with a lot of stuff I do not need. I do not want to use .sync(). I do not want to use migrations. I have the structure of my database created already and I want Sequelize to attach to it.
Is it possible insert and retrieve several rows related at the same time and getting / using a single Sequelize command / object? How?
Again, by "related data" I mean data "linked" by sharing the same foreign key.
Is it possible insert and retrieve several rows related at the same
time and getting / using a single Sequelize command / object? How?
Yes. What you need is eager loading.
Look at the following example
const User = sequelize.define('user', {
username: Sequelize.STRING,
});
const Address = sequelize.define('add', {
address: Sequelize.STRING,
});
const Designation = sequelize.define('designation', {
designation: Sequelize.STRING,
});
User.hasOne(Address);
User.hasMany(Designation);
sequelize.sync({ force: true })
.then(() => User.create({
username: 'test123',
add: {
address: 'this is dummy address'
},
designations: [
{ designation: 'designation1' },
{ designation: 'designation2' },
],
}, { include: [Address, Designation] }))
.then(user => {
User.findAll({
include: [Address, Designation],
}).then((result) => {
console.log(result);
});
});
In console.log, you will get all the data with all its associated models that you want to include in the query
I am retrieving data from Firebase db using REST call. So i have a data looking like this
user
{
123456:
{
Email: "test#hotmail.com",
Password: "John Doe"
}
654321:
{
Email: "test2#hotmail.com",
Password: "Jane Doe"
}
}
The query I used is
firebaseurl/user.json?orderBy="Email"&equalTo="test#hotmail.com"
Is it possible if I query without the key value 123456 being retrieve? Because whenever I try to use the data, for instance console.log(user.Email), I am getting undefined. But when I do it likeconsole.log(user[123456].Email) then will I get the result I desire.
May I know if there's a way to do it? Or a way to access to the child element without user[keyvalue].
As it is expected only single record in return you can use:
const user = obj[Object.keys(rslt)[0]]
Or you can loop over the keys
const usersArr = Object.keys(rslt).map(usr => {
... manipulate usr
return usr
})
I want to the delete a few rows in MySQL table using loopabck. But I don't want to use the id to delete the record. I'm trying it in Angular SDK. My code is:
ModelName.destroyById({ fieldName : myValue })
.$promise
.then(function() {
});
I'd be very thankful for ideas.
Seems like you need to use the destroyAll method, which does what you want, but you need to set up remoting for it first, since it's disabled by default:
ModelName.remoteMethod('destroyAll', {
isStatic: true,
description: 'Delete all matching records',
accessType: 'WRITE',
accepts: {arg: 'where', type: 'object', description: 'filter.where object'},
http: {verb: 'del', path: '/'}
});
Then after that you regenerate your Angular client and you can use it like this in the client side:
ModelName.destroyAll({ filter: { fieldName : myValue }}).$promise.then(...)
Note that using destroyAll is risky as if you have any mistakes in your code you will end up losing data. Enabling it to client side might be security concern.
Another way to do this is to write your own remote method which uses destroyAll in turn with proper validation of the inputs.
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();