我在云平台下建立了数据库“queryU”，字段有DN、Pt、Ps、L、d、ID等，我想通过其中四个参数，找到唯一一条记录，可是怎么也不能得到，请高手指点一二、谢谢

const DB1 = wx.cloud.database().collection("queryU")

    let that = this;

       DB1.where({

        DN: that.data.DN1,

        Pt: that.data.Pt,

        Ps: that.data.Ps,

        d: that.data.dn,

        N: that.data.tube,

        L: that.data.L,

      })

        .get({

          success: function(res) {

            that.setData({

              IDU: res.data[0].ID,

            })

            console.log("name" + IDU);

          },