Dialect needs to be explicitly supplied as of v4.0.0

问题

I have been working on a NodeJS project which uses PostgreSQL database. I am trying to implement migration to the database. Also, using Sequelize. After setting up the migration folder and config, it throws error while running db:migrate

The error is: "Dialect needs to be explicitly supplied as of v4.0.0"

回答1:

Solution for me was based on what I had set for my NODE_ENV variable.

echo $NODE_ENV

If you do not have anything set for that variable, try setting it with the following:

export NODE_ENV=development

If a value is present, make sure you have an entry in your config file for that value. For me, I like to use local. So I had to update my config to this:

{
 local: {
  username: 'root',
  password: null,
  database: 'database_dev',
  host: '127.0.0.1',
  dialect: 'postgres'
  },
 development: {
  username: 'root',
  password: null,
  database: 'database_dev',
  host: '127.0.0.1',
  dialect: 'postgres'
  },
  test: {
  username: 'root',
  password: null,
  database: 'database_test',
  host: '127.0.0.1',
  dialect: 'postgres'
 },
 production: {
  username: 'root',
  password: null,
  database: 'database',
  host: '127.0.0.1',
  dialect: 'postgres'
 }
}

回答2:

Check the dialect once.

const Sequelize = require('sequelize'); // Option 1: Passing parameters separately const sequelize = new Sequelize('database', 'username', 'password', { host: 'localhost', dialect: /* one of 'mysql' | 'mariadb' | 'postgres' | 'mssql' */ });

回答3:

I got same error and I saw this mistake in the code.

  title: {
    type: Sequelize,
    allowNull: false,
  },

Changed my code with this and problem is solved:

  title: {
    type: Sequelize.STRING,
    allowNull: false,
  },

回答4:

did you forget to add the dialect to your config? see: http://docs.sequelizejs.com/manual/tutorial/migrations.html

回答5:

Check your config file (env names)

{
  development: {
    username: 'root',
    password: null,
    database: 'database_development',
    host: '127.0.0.1',
    dialect: 'mysql'
  },
  test: {
    username: 'root',
    password: null,
    database: 'database_test',
    host: '127.0.0.1',
    dialect: 'mysql'
  },
  production: {
    username: 'root',
    password: null,
    database: 'database_production',
    host: '127.0.0.1',
    dialect: 'mysql'
  }
}