如何为Knex设置默认数据库？knexfile.js正确配置方式咨询

Got it, let's sort out this default database configuration issue for you. The default: true flag you tried doesn't work because Knex doesn't recognize that property in the knexfile structure—each top-level key in the exported object is treated as an environment name (like development, production), and Knex uses the NODE_ENV environment variable to pick which one to use (falling back to development if NODE_ENV isn't set).

Here are the most common and correct ways to set your desired default database:

1. Rename your target environment to development (simplest default) #

Knex automatically loads the development configuration if no environment is specified. Just rename your local key to development, and you're good to go:

module.exports = {
  development: {
    client: 'postgresql',
    connection: {
      database: 'main'
    },
    pool: {
      min: 2,
      max: 10
    }
  },
  // Add other environments like production/staging here if needed
};

Then initialize Knex without extra parameters—it will use the development config by default:

const knex = require('knex')(require('./knexfile'));

2. Keep your local environment and explicitly set it as default #

If you want to keep the local name, you have two options:

Option A: Specify the environment directly when initializing Knex #

Just reference the local config explicitly when creating your Knex instance:

const knexConfig = require('./knexfile');
const knex = require('knex')(knexConfig.local);

Option B: Fall back to local if NODE_ENV isn't set #

You can modify your initialization code to use local as the default when no environment variable is provided:

const env = process.env.NODE_ENV || 'local';
const knexConfig = require('./knexfile')[env];
const knex = require('knex')(knexConfig);

This way, if you run your app with NODE_ENV=production node app.js, it will use the production config; otherwise, it defaults to local.

3. Share the default config across multiple environments #

If you want local to be the base for other environments, you can define it once and reuse it:

const defaultConfig = {
  client: 'postgresql',
  connection: {
    database: 'main'
  },
  pool: {
    min: 2,
    max: 10
  }
};

module.exports = {
  local: defaultConfig,
  development: defaultConfig, // Makes development use the same default settings
  production: {
    ...defaultConfig,
    connection: {
      database: 'main_prod',
      // Add production-specific connection details like user/password here
    }
  }
};

That's all—pick the method that fits your workflow best!

内容的提问来源于stack exchange，提问作者Allyl Isocyanate