knex migrate 抛出错误关系已经存在

Question

我使用 Heroku Postgres database and knexjs as SQL query builder in my node.js application. I try to run the latest knex migration，但出现错误 relation already exists。当我尝试通过 sql 命令 CREATE TABLE 创建 table 时，它可以正常工作。

knexfile.js

// Update with your config settings.

require('dotenv').config({ path: require('find-config')('.env') });

module.exports = {
  development: {
    client: 'pg',
    useNullAsDefault: true,
    connection: process.env.DATABASE_URL,
    searchPath: ['knex', 'public'],
  },

  staging: {
    client: 'postgresql',
    connection: {
      database: 'my_db',
      user: 'username',
      password: 'password'
    },
    pool: {
      min: 2,
      max: 10
    },
    migrations: {
      tableName: 'knex_migrations'
    }
  },

  production: {
    client: 'postgresql',
    connection: {
      database: 'my_db',
      user: 'username',
      password: 'password'
    },
    pool: {
      min: 2,
      max: 10
    },
    migrations: {
      tableName: 'knex_migrations'
    }
  }
};

最新迁移文件

migrations/20180120183247_users_test.js

/* eslint func-names: 0 */

exports.up = function (knex) {
  return knex.schema
    .createTable('users', (table) => {
      table.increments('id').primary();
      table.string('user_name', 100);
      table.text('password');
      table.string('email', 254);
    });
};

exports.down = function (knex) {
  return knex.schema
    .dropTableIfExists('users');
};

当我运行命令时：

knex migrate:latest --env development

我收到错误：

Using environment: development
Knex:warning - migration file "20180120184707_initial_schema.js" failed
Knex:warning - migration failed with error: create table "users" ("id" serial primary key, "user_name" varchar(100), "password" text, "email" varchar(254)) - relation "users" already exists
error: relation "users" already exists
    at Connection.parseE (.../node_modules/pg/lib/connection.js:546:11)
    at Connection.parseMessage (.../node_modules/pg/lib/connection.js:371:19)
    at TLSSocket.<anonymous> (.../node_modules/pg/lib/connection.js:114:22)
    at emitOne (events.js:115:13)
    at TLSSocket.emit (events.js:210:7)
    at addChunk (_stream_readable.js:252:12)
    at readableAddChunk (_stream_readable.js:239:11)
    at TLSSocket.Readable.push (_stream_readable.js:197:10)
    at TLSWrap.onread (net.js:589:20)

如果我连接到数据库和运行命令：

select * from users;

我得到：

ERROR:  relation "users" does not exist
LINE 1: select * from users;

在 Heroku Postgres 设置中运行重置数据库以删除所有数据。我等了 2-3 分钟，然后再次尝试运行最新的迁移，但我收到了相同的错误消息。

Answer 1

我不知道 knex migrate:latest 命令运行所有迁移文件，所以 table users 是在以前的迁移文件中创建的，这就是问题所在。

Answer 2

我遇到了这个问题，希望有一个简单的解决方案，以防万一其他人想知道您可以做些什么来解决这个问题：

如果您的数据库确实与迁移文件匹配：

进入 knex_migrations table（或者如果您将其重命名为其他内容，则记录迁移的 table）并添加包含迁移文件名称的行name 列中的问题。

要检查它是否正常工作，请尝试 knex migrate:list

knex migrate 抛出错误关系已经存在

knex migrate throws error relation already exists

postgresql

heroku

knex.js

heroku-postgres

node-postgres