I try to use Sequelize ORM. Reading documention to this i saw the example
const Project = sequelize.define('project', {
title: Sequelize.STRING,
description: Sequelize.TEXT
})
const Task = sequelize.define('task', {
title: Sequelize.STRING,
description: Sequelize.TEXT,
deadline: Sequelize.DATE
})
I solved to apply practically in shell node.
I started node in command line
var sequelize = require('sequelize')
sequelize.define ...
But node said me it is wrong and sequelize dont have the method "define".
SO i think now where is my error and im wrong understand documentation
You need to create an instance of sequelize:
const Sequelize = require("sequelize");
const sequelize = new Sequelize(
database,
username,
password,
{
host: host,
logging: false,
dialect: "mysql",
port: 3306,
pool: {
max: 5,
min: 0,
idle: 10000
}
}
);
And after that do define:
const Project = sequelize.define('project', {
title: Sequelize.STRING,
description: Sequelize.TEXT
})
const Task = sequelize.define('task', {
title: Sequelize.STRING,
description: Sequelize.TEXT,
deadline: Sequelize.DATE
})
Related
const Sequelize = require("sequelize");
const db = require("../db");
const user = require("../models/userModel");
const employees = db.define("employees", {
firstname: {
type: Sequelize.STRING,
allowNull: false,
unique: true,
},
lastname: {
type: Sequelize.STRING,
allowNull: false,
},
userId: {
type: Sequelize.INTEGER,
references: {
model: user,
key: "id",
},
},
});
employees.sync({ alter: true });
module.exports = employees;
Okay,so I have two tables already created, in my terminal they appear with create table if not exists but not for this table,but not for this table,I missed something? pg version :8.7.1
const { Sequelize } = require("sequelize");
const sequelize = new Sequelize("xxx", "xxx", "xxx", {
host: "localhost",
dialect: postgres,
port: 5000,
});
module.exports = sequelize;
db file
sync is (ironically) an asynchronous operation. You need to await it:
await employees.sync({ alter: true });
I am new to nodejs and Sequelize and have been having an issue that I cannot figure out how to get over. I want to use a connection I created and exported it to a module.
Like this:
const dotEnv = require('dotenv');
const Sequelize = require('sequelize');
dotEnv.config();
module.exports.connection = async () => {
try{
const sequelize = new Sequelize(process.env.DB_DATABASE, process.env.DB_USER, process.env.DB_PASSWORD, {
host: process.env.DB_HOST,
port: process.env.DB_PORT,
dialect: 'mysql',
logging: false,
define: {
charset: 'utf8',
collate: 'utf8_general_ci',
},
});
await sequelize
.authenticate()
.then(() => {
console.log('Connection has been established successfully.');
})
.catch(error => {
throw error;
});
}catch(error){
throw error;
}
}
I then have another file where I want to use it that looks like this
const Sequelize = require('sequelize');
const { connection }= require('../database');
const accountModel = connection.define('accounts', {
// attributes
id: {
type: Sequelize.UUID,
defaultValue: Sequelize.UUIDV4,
primaryKey: true
},
name: {
type: Sequelize.STRING,
allowNull: false
},
email: {
type: Sequelize.STRING,
unique: true
},
password: {
type: Sequelize.STRING,
allowNull: false,
//is: /^[0-9a-f]{64}$/i
},
permission: {
type: Sequelize.STRING,
allowNull: false
},
discount: {
type: Sequelize.INTEGER,
allowNull: false
}
}, {
freezeTableName: true
});
module.exports = connection.model('accounts', accountModel);
The problem is that I get told that: TypeError: connection.define is not a function,
The connection works, the database is running, everything else works
And last if I do it like this, it works too:
const dotEnv = require('dotenv');
const Sequelize = require('sequelize');
dotEnv.config();
const sequelize = new Sequelize(process.env.DB_DATABASE, process.env.DB_USER, process.env.DB_PASSWORD, {
host: process.env.DB_HOST,
port: process.env.DB_PORT,
dialect: 'mysql',
logging: false,
define: {
charset: 'utf8',
collate: 'utf8_general_ci',
},
});
const accountModel = sequelize.define('accounts', {
// attributes
id: {
type: Sequelize.UUID,
defaultValue: Sequelize.UUIDV4,
primaryKey: true
},
name: {
type: Sequelize.STRING,
allowNull: false
},
email: {
type: Sequelize.STRING,
unique: true
},
password: {
type: Sequelize.STRING,
allowNull: false,
//is: /^[0-9a-f]{64}$/i
},
permission: {
type: Sequelize.STRING,
allowNull: false
},
discount: {
type: Sequelize.INTEGER,
allowNull: false
}
}, {
freezeTableName: true
});
module.exports = sequelize.model('accounts', accountModel);
I am really not sure why the module one does not work but the direct method does. I have tried to search Google and Stack Overflow for a solution.
The problem in your first approach is that you exported first of all an async function and not the Sequelize instance (as it is in your second example) and secondly the function itself is not returning anything. That's why there is no connection.define() function when you require that in another file.
try this in database.js and it should work:
module.exports.connection = new Sequelize(process.env.DB_DATABASE, process.env.DB_USER, process.env.DB_PASSWORD, {
host: process.env.DB_HOST,
port: process.env.DB_PORT,
dialect: 'mysql',
logging: false,
define: {
charset: 'utf8',
collate: 'utf8_general_ci',
},
});
You can do all that authenticate() and try {} catch (error) {} somewhere else for example in your very first js file where you starting the server by requiring the same database.js file. But for the model definitions it's important that you are exporting just the new Sequelize() instance to them to be able to use define()
I would do something like this. In the connections file you export the function then in the accountModel file you import and invoke the function.
connection.js:
exports.connection= async function() { // Stuff here }
accountModel.js:
const { connection }= require('../database');
let connection = await connection.connection();
I am trying to set up sequelize in my node project and for now I have
//sequelize init
const { DataTypes } = Sequelize;
const sequelize = new Sequelize({
database: database,
username: user,
host: server,
password: password,
dialect: 'mssql',
dialectOptions: {
options: {
useUTC: true,
dateFirst: 1,
}
},
define:{
timestamps:false,
paranoid:false,
freezeTableName: true
}
});
//and my Model
const User= sequelize.define('User', {
// attributes
id: {
field:'Id',
type: Sequelize.INTEGER,
allowNull: false,
primaryKey: true
} ,
startTime: {
field:'startTime',
type: Sequelize.DATE
}
});
I try to setup version:true to enable Optimistic Locking
I put it in model
const Vessel = sequelize.define('FDMData', {
// attributes
id: {
field:'vesselId',
type: Sequelize.INTEGER,
allowNull: false,
primaryKey: true
} ,
startTime: {
field:'startTime',
type: Sequelize.DATE
}
},{
version:true
}
);
and I get Unhandled rejection SequelizeDatabaseError: Invalid column name 'version'.
I also tried to set it as global while init
const { DataTypes } = Sequelize;
const sequelize = new Sequelize({
database: database,
username: user,
host: server,
password: password,
dialect: 'mssql',
dialectOptions: {
options: {
useUTC: true,
dateFirst: 1,
}
},
define:{
timestamps:false,
paranoid:false,
freezeTableName: true,
version: true
}
});
and again, I get Unhandled rejection SequelizeDatabaseError: Invalid column name 'version'.
What am I missing? How can I fix this?
Thanks
When you set version: true and you are creating your database structure manually, sequelize expect to find a column
named version on the table : so add a column version INTEGER NOT NULL DEFAULT 0 to your tables.
You can also name the versioning column what ever you want, just passe a string version: "myVersionColumn"
If you let sequelize handle the creation of the DB structure, it generate a DDL for the FDMData table that look like
CREATE TABLE IF NOT EXISTS FDMData (
vesselId INTEGER NOT NULL ,
startTime DATETIME,
version INTEGER NOT NULL DEFAULT 0,
PRIMARY KEY (vesselId)
)
and your code work juste fine. For example
Vessel.sync().then(model=> {
// or sequelize.sync()
console.log(model)
}).catch(error=> {
console.log(error)
})
you are almost there, based on the docs, setting version to true or set it to whatever name you want do the trick
Enable optimistic locking. When enabled, sequelize will add a version count attribute
to the model and throw an OptimisticLockingError error when stale instances are saved.
Set to true or a string with the attribute name you want to use to enable.
however, just in the next section to optimistic locking -Database synchronization- it says
When starting a new project you won't have a database structure and using Sequelize you won't need to
meaning, sequelize doesn't depend on a sql structure already set in your database for this purpose if you sync your models after you define them except for the database definition, it will automatically create it for you including the version field, here is an example
const Sequelize = require('sequelize');
const config = {
username: "root",
password: "123",
tableName: "test",
options: {
host: '127.0.0.1',
dialect: 'mysql',
pool: {
max: 3,
min: 1,
acquire: 30000,
idle: 10000
},
define: {
timestamps:false,
paranoid:false,
freezeTableName: true,
version: true
}
}
};
const sequelize = new Sequelize(config.tableName, config.username, config.password, config.options);
//and my Model
const User= sequelize.define('User', {
// attributes
id: {
field:'Id',
type: Sequelize.INTEGER,
allowNull: false,
primaryKey: true
} ,
startTime: {
field:'startTime',
type: Sequelize.DATE
}
});
User.sync();
if you run this script you will see the following sql statements executed
Executing (default): CREATE TABLE IF NOT EXISTS User (Id INTEGER
NOT NULL , startTime DATETIME, version INTEGER NOT NULL DEFAULT 0,
PRIMARY KEY (Id)) ENGINE=InnoDB;
Executing (default): SHOW INDEX FROM User
however, if you don't want sequelize to sync your models, you have to explicitly have that field in your already established tables, but not explicitly defined in sequelize model as it will automatically know its there.
Adding an example, a User model (using sequelize v6):
const { Sequelize, Model, DataTypes, Deferrable, DatabaseError } = require('sequelize');
const sequelize = require('../lib/db.sequelize').db;
class User extends Model {
}
User.init({
// The following specification of the 'id' attribute could be omitted
// since it is the default.
id: {
allowNull: false,
primaryKey: true,
type: DataTypes.UUID,
defaultValue: DataTypes.UUIDV4,
},
version: { // Optimistic Locking
allowNull: false,
type: DataTypes.INTEGER,
defaultValue: 0
},
name: {
allowNull: false,
type: DataTypes.STRING,
},
email: {
allowNull: false,
type: DataTypes.STRING,
unique: true,
validate: {
isEmail: true
}
}
}, {
sequelize,
modelName: 'user',
version: true, // Optimistic Locking
indexes: [
{
name: 'user_id_index',
method: 'BTREE',
fields: ['id'],
},
{
name: 'user_email_index',
method: 'BTREE',
fields: ['email'],
}
],
freezeTableName: true
});
module.exports = User;
Note that a version attribute was added to the model as well as passing the "version: true" to the options.
I have 2 express.js applications and run sequelize.sync(), but in my first app it generate the tables, and the others not generate the tables, i wonder why, because the script is identic.
database.js
const Sequelize = require('sequelize');
const sequelize = new Sequelize('student-affairs', 'root', '', {
dialect: 'mysql',
host: 'localhost',
operatorsAliases: false,
});
module.exports = sequelize;
organization.js
const Sequelize = require('sequelize');
const sequelize = require('../configs/database');
const Organization = sequelize.define('organization', {
id: {
type: Sequelize.INTEGER,
allowNull: false,
primaryKey: true,
autoIncrement: true
},
name: {
type: Sequelize.STRING,
allowNull: false
},
logo: {
type: Sequelize.STRING
},
createdBy: {
type: Sequelize.INTEGER,
allowNull: false
},
updatedBy: {
type: Sequelize.INTEGER,
allowNull: false
}
});
module.exports = Organization;
app.js
// Database
const sequelize = require('./configs/database');
sequelize
.sync()
.then(result => {
console.log(result);
app.listen(3001);
})
.catch(err => {
console.log(err);
});
But after i log it, it always return the models empty like this
models: {},
modelManager: ModelManager { models: [], sequelize: [Circular] },
it doesn't have the models. anyone can explain why? thanks
I just realize that i am not call the organization model in app.js, once i define it in app.js and it fix the problem.
I think it's a basic mistake. Now i understand how it works.
// Models
const Organization = require('./models/organization');
sequelize
.sync()
.then(result => {
app.listen(3000);
})
.catch(err => {
console.log(err);
});
The names of my tables in the .create() method function and model definitions are swinging from singular to plural and vice-versa. Why does Sequelize have this functionality at all? And why is disabling it so unstable?
The table names in my database are (as in the code) "user", "email", "settings". But when doing the INSERT and SELECT SQL statements Sequelize singularizes the names as if I there was need for a library to choose the best name for my database tables! Because of that, some INSERTs fail.
Here is my code:
// DEPENDENCIES
const Sequelize = require('sequelize');
// Connection set up:
const sequelize = new Sequelize(
'sql_database_1',
'sqlusername1',
'dbpassw0rd',
{ // Sequelize options:
host: 'localhost',
port: 3306,
dialect: 'mysql',
operatorsAliases: false,
pool: {
max: 5,
min: 0,
acquire: 30000,
idle: 10000
},
logging: console.log,
define: {
freezeTableName: true, // Do not change my table names.
timestamps: false // I will do this individually, thanks.
},
});
// Set up models:
const User = sequelize.define('user',
{ // Database columns:
user_id: {
type: Sequelize.INTEGER,
primaryKey: true,
autoIncrement: true
},
column1: Sequelize.STRING,
});
const Settings = sequelize.define('settings',
{ // Database columns:
entry_id: {
type: Sequelize.INTEGER,
primaryKey: true,
autoIncrement: true
},
owner_id: Sequelize.INTEGER,
column1: Sequelize.STRING
});
const Email = sequelize.define('email',
{ // Database columns:
entry_id: {
type: Sequelize.INTEGER,
primaryKey: true,
autoIncrement: true
},
owner_id: Sequelize.INTEGER,
column1: Sequelize.STRING
});
// Set up associations:
User.hasOne(Settings,
{ // Options:
foreignKey: 'owner_id'
});
User.hasMany(Email,
{ // Options:
foreignKey: 'owner_id'
});
// Actions:
sequelize
.sync({
force: true
})
.then(function() {
User
.create({
column1: 'test123',
settings: { // STACK OVERFLOW: Not working because of Sequelize singularizing the name.
column1: 'This is dummy address'
},
emails: [ // STACK OVERFLOW: I need to write this table name in plural to work because Sequelize is changing MY names...
{ column1: 'Some data here' },
{ column1: 'Other data there' }
],
},
{
include: [Settings, Email]
})
})
.then(function() {
User
.findOne({
include: [Settings, Email],
})
.then(function(result) {
console.log('FindAll results:\n', JSON.stringify(result));
});
});
As you can see, I am using "define: { freezeTableName: true }" in the object dedicated to set up Sequelize options. It is only working when creating the new table names: it does not pluralize them. The INSERT and SELECT statements still have a similar same problem: they are being singularized.
Can this be a bug?
It has to do with the association you define. For settings, we have hasOne relationship. Hence the name is singular. For emails, we have hasMany, and henve the plural.
Lets look at an example below.
const User = sequelize.define('user', {
username: Sequelize.STRING,
});
const Email = sequelize.define('emails', {
text: Sequelize.STRING,
});
User.hasMany(Email);
sequelize.sync({ force: true })
.then(() => User.create({
username: 'test1234',
emails: {
text: 'this is dummy Email123'
},
}, { include: [Email] }))
.then(user => {
console.log(user.dataValues);
});
I have used emails because User have hasMany relationship with Email.
If I change the relationship type to hasOne, I will have to use singular name.
const User = sequelize.define('user', {
username: Sequelize.STRING,
});
const Email = sequelize.define('emails', {
text: Sequelize.STRING,
});
User.hasOne(Email);
sequelize.sync({ force: true })
.then(() => User.create({
username: 'test1234',
email: {
text: 'this is dummy Email123'
},
}, { include: [Email] }))
.then(user => {
console.log(user.dataValues);
});