server-v2/app/service/relation/relationStudentCoach.js

'use strict';
const { CrudService } = require('naf-framework-mongoose-free/lib/service');
const { BusinessError, ErrorCode } = require('naf-core').Error;
const _ = require('lodash');
const assert = require('assert');

//
class RelationStudentCoachService extends CrudService {
  constructor(ctx) {
    super(ctx, 'relationstudentcoach');
    this.model = this.ctx.model.Relation.RelationStudentCoach;
  }

  // 创建关系前,先查下有没有,有就别创建了
  async beforeCreate(data) {
    const { coach_id, student_id, school_id } = data;
    const num = await this.model.count({ student_id, coach_id, school_id });
    if (num <= 0) {
      return data;
    }
    throw new BusinessError(ErrorCode.DATA_EXISTED, '教练已在该学校有与学生的关联,无需重复添加');
  }
}

module.exports = RelationStudentCoachService;