server-v2/app/service/relation/relationStudentSchool.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 RelationStudentSchoolService extends CrudService {
  constructor(ctx) {
    super(ctx, 'relationstudentschool');
    this.model = this.ctx.model.Relation.RelationStudentSchool;
  }
  // 创建关系前,先查下有没有,有就别创建了
  async beforeCreate(data) {
    const { student_id, school_id } = data;
    const num = await this.model.count({ student_id, school_id });
    if (num <= 0) { return data; }
    throw new BusinessError(ErrorCode.DATA_EXISTED, '学员已入学,无需重复添加');
  }
}

module.exports = RelationStudentSchoolService;