egg-knex-model

egg-knex-model

a knex plugin for egg.js

Usage

1. Run npm i egg-knex-model
2. Enable egg-knex-model

{
  knex: {
    enable: true,
    package: 'egg-knex-model',
  },
}

1. Configure egg-knex-model in config/config.default.ts

{
  knex: {
    client: {
      // please put knex config here
      // https://knexjs.org/#Installation-client
      client: 'pg',
      version: '7.2',
      connection: {
        host : '127.0.0.1',
        user : 'your_database_user',
        password : 'your_database_password',
        database : 'myapp_test'
      }
    },
    app: true,
    agent: false,
  },
}

1. Configure egg-ts-helper in package.json (TypeScript ONLY)

{
  "egg": {
    "typescript": true,
    "tsHelper": {
      "watchDirs": {
        "model": {
          "pattern": "**/*.(ts|js)",
          "path": "app/model",
          "generator": "class",
          "interface": "IModel",
          "caseStyle": "lower",
          "trigger": [
            "add",
            "unlink"
          ],
          "interfaceHandle": false
        }
      }
    }
  }
}

1. Add model in app/model

// app/model/User.ts
import { BaseModel, BaseEntity } from 'egg-knex-model';

// or if you don't want `id`, `created_at` and `updated_at`,
// you can directly define the interface of entity without `extends`
// or you can use PartialBaseEntity<'id'> to get { id:number } and `extends` it
interface E extends BaseEntity {
  username:string;
  points:number;
}

export default class extends BaseModel<E> {
  protected tableName = 'user';

  // you can add some method like this,
  // or just use methods in BaseModel
  getByUsername(username:string) {
    return this.getOne({username});
  }
}

1. Use model

 // app/service/Test.ts
 export default class Test extends Service {
   public async test() {
     // transaction is easy to use
     // let's use it to add a new user and increment it's points
     await this.app.knex.trx(async model => {
       // must use `model` instead of `this.app.model` in a transaction
       await model.user.insert({
         username: '23333',
         points: 100,
       });
       await model.user.increment({ username: '23333'}, 'points');
     });

     // use getOne to get the user
     console.log(await this.app.model.user.getOne({
       username: '23333',
     }));
     /*
     {
       id: 5,
       username: '23333',
       points: 101,
       created_at: 2018-10-27T19:18:54.703Z,
       updated_at: 2018-10-27T19:18:54.703Z
     }
     */

     // it should auto rollback when an error occurred
     try {
       await this.app.knex.trx(async model => {
         await model.user.update({}, { username: '555555' });
         throw new Error('this transaction should be rolled back');
       });
     } catch (e) {
       console.error(e);
       /*
       Error: this transaction should be rolled back
           at app.knex.trx (/Users/erona/projects/bhdh/app/service/Test.ts:27:15)
           at <anonymous>
       From previous event:
           at /Users/erona/projects/egg-knex-model/node_modules/knex/lib/transaction.js:91:14
           at runCallback (timers.js:794:20)
       From previous event:
           at new Transaction (/Users/erona/projects/egg-knex-model/node_modules/knex/lib/transaction.js:63:41)
           at Client_PG.transaction (/Users/erona/projects/egg-knex-model/node_modules/knex/lib/client.js:152:12)
           at Function.transaction (/Users/erona/projects/egg-knex-model/node_modules/knex/lib/util/make-knex.js:65:21)
           at Object.createTrx (/Users/erona/projects/egg-knex-model/dist/lib/transaction.js:57:17)
           at Function.knexEx.trx (/Users/erona/projects/egg-knex-model/dist/lib/loader.js:90:60)
           at Test.test (/Users/erona/projects/bhdh/app/service/Test.ts:25:27)
           at <anonymous>
       */
     }
   }
 }