Required configuration option 'client' is missing.

Documentation states:

You can even use knex without a connection, just for its query building features.

Though running direct example from docs:

const knex = require(‘knex’)({});

Throws error:

> knex = require('knex')({})
Error: knex: Required configuration option 'client' is missing.
    at new Client (/home/ginden/.../node_modules/knex/lib/client.js:108:11)
    at Knex (/home/ginden/.../node_modules/knex/lib/index.js:60:34)
    at repl:1:23

[Haisum92]

@Ginden , it raised due to two reasons at my side and so sharing for ease Error: knex: Required configuration option ‘client’ is missing.

1. Wrong environment name in the knexfile.js. In my .env NODE_ENV = development and at knexfile.js there was no entry in it

    module.exports = {
   
     test: {
       client: config.DB_DIALECT,
       connection: {
         host      : process.env.DB_HOST,
         user      : process.env.DB_USERNAME,
         password  : process.env.DB_PASSWORD,
         database  : (process.env.DB_NAME == "test") ? process.env.DB_NAME_TEST : process.env.DB_NAME,
         timezone  : config.GLOBAL_TIME_ZONE
       },
       migrations: {
         tableName: migrationTable
       }
     },
     Local: {
       client: config.DB_DIALECT,
       connection: {
         host      : process.env.DB_HOST,
         user      : process.env.DB_USERNAME,
         password  : process.env.DB_PASSWORD,
         database  : (process.env.DB_NAME == "test") ? process.env.DB_NAME_TEST : process.env.DB_NAME,
         timezone  : config.GLOBAL_TIME_ZONE
       },
       migrations: {
         tableName: migrationTable
       }
     },
     
     staging: {
       client: config.DB_DIALECT,
       connection: {
         host      : process.env.DB_HOST,
         user      : process.env.DB_USERNAME,
         password  : process.env.DB_PASSWORD,
         database  : process.env.DB_NAME,
         timezone  : config.GLOBAL_TIME_ZONE
       },
       migrations: {
         tableName: migrationTable
       }
     },
   
     production: {
       client: config.DB_DIALECT,
       connection: {
         host      : process.env.DB_HOST,
         user      : process.env.DB_USERNAME,
         password  : process.env.DB_PASSWORD,
         database  : process.env.DB_NAME,
         timezone  : config.GLOBAL_TIME_ZONE
       },
       migrations: {
         tableName: migrationTable
       }
     }
   
   };
   

2. Wrong client name at configrations
client: config.DB_DIALECT, // either key doesn't exits or wrong name at config file 

[elhigu]

Docs are out of date: https://github.com/knex/documentation/issues/28