记录一次moogdb 关联表查询

    getQuery (searchPanelData: any) {

        let _searchPanelData: any = {}

        if (!searchPanelData) {

            return _searchPanelData

        }

        Object.keys(searchPanelData).map((key: string) => {

            const item: any = searchPanelData[key]

            if (!item) {

                return

            }

            if (typeof item === 'string') {

                _searchPanelData[key] = new RegExp(item, 'i')

            } else if (Array.isArray(item) && item.length) {

                if (key === 'risk_type') {

                    _searchPanelData[key] = item

                } else {

                    _searchPanelData[key] = { '$in': item }

                }

            } else if (Object.prototype.toString.call(item) === '[object Object]') {

                const start = item['start']

                const end = item['end']

                _searchPanelData[key] = {

                    '$gte': start,

                    '$lte': end

                }

            }

        })

        return _searchPanelData

    }

   

 getOffsetAndLimit (p: { pageSize?: number, page?: number } = {}): { offset: number, limit: number } {
      const limit = p.pageSize || 20
      let page = p.page || 1
      if (page <= 0) {
          page = 1
      }
      const offset = (page - 1) * limit
      return {
          offset,
          limit,
      }
  }
    /**
     * 获取列表数据
     * @param params 
     * @returns 
     */
    async getList<T extends any> (params: ICurd.ICommonListParams) {
        const { pagination, query, sort, collection, env } = params
        let _query = this.getQuery(query)
        const [ riskCol ] = await this.mdbService.getCols({env, collections: [collection]})
        // 联表查询
        let cursor = await riskCol.aggregate([
          {
            '$lookup': {
              // 关联的表
              from: 'combo_relation_risk',
              // 用 localField 的字段 匹配 foreignField 的字段
              localField: 'risk_code',
              foreignField: 'relation_risk_list',
              // 关联表的数据返回到 as 的字段中
              as: 'relation_conbo_code_list'
            }
          },
          // 查询条件
          {
            '$match': { ..._query, _deleted: { '$nin': [true] } }
          }
        ])
        const offsetAndLimit = {
            offset: 0,
            limit: 0
        }
        if (pagination) {
          const { offset, limit } = this.getOffsetAndLimit(pagination)
          offsetAndLimit.offset = offset
          offsetAndLimit.limit = limit
      }
      if (pagination) {
          // 不传 pagination 则读取全部的数据，一般不推荐，前端无法获取全部数据
          cursor.skip(offsetAndLimit.offset).limit(offsetAndLimit.limit)
      }
        cursor = cursor.sort(sort || { update_at: -1 })
        const items = await cursor.toArray()
        const search = Object.assign({ _deleted: { '$nin': [true] } }, _query)
        // 获取总条数
        const cursorV2 = riskCol.find(search)
        const count = await cursorV2.count()
        return { items, count, pagination }
    }