Mongoose findOne 在类型 mongoose.Schema.Types.ObjectId 上返回 null

Question

I have a Model that contains a foreign key eid of type mongoose.Schema.Types.ObjectId . Whenever I try to filter records using that particular column i get a null result yet the record exists. Here is the schema.

const attendanceSchema = mongoose.Schema(
  {
    eid: {
      type: mongoose.Schema.Types.ObjectId,
      ref: "Employee",
      required: true,
    },
    month: {
      type: String,
      required: true,
    },
    paidAmount: {
      type: Number,
      default: 0,
    },
    yearMonth: {
      type: Number,
      required: true,
    },
  },
  {
    timestamps: true,
  }
);

here is the query

  const attendance = await Attendance.findOne({
      eid:req.body.eid,
    });

I also tried casting eid from req.body to mongoose.Schema.Types.ObjectId

 const attendance = await Attendance.findOne({
      eid: mongoose.Types.ObjectId(req.body.eid),
    });

Answer 1

I was able to solve the problem. I Found out that I used req.body.eid rather than req.body.employeeId .