postgresql - knex migrate 抛出错误关系已经存在

Question

我使用 Heroku Postgres数据库和knexjs作为我的 node.js 应用程序中的 SQL 查询生成器。我尝试运行最新的 knex migration ，但出现错误 relation already exists。当我尝试通过 sql 命令 CREATE TABLE 创建表时，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'
    }
  }
};

• 最新的迁移文件

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

我得到错误:

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并运行命令:

select * from users;

我得到:

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

在 Heroku Postgres 设置中，我运行重置数据库以删除所有数据。我等了 2-3 分钟，然后尝试再次运行最新的迁移，但我得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，所以表 users 是在以前的迁移文件中创建的，这就是问题所在。