将objectID列为select中的值并保存表单

我有两个模式,一个是学校,另一个是老师。下面是模式的样子

var SchoolSchema = new Schema({    
    name: {
        type: String,
        required: true,        
        unique: true
    },
    status: {
        type: Number,
        default: 1
    }
});

module.exports = mongoose.model('School', SchoolSchema);

老师:

var TeacherSchema = new Schema({    
    schoolID: {
        type: mongoose.Schema.Types.ObjectId, ref: 'School'
    },
    name: {
        type: String,
        required: true
    },
    email: {
        type: String,
        unique: true,
        required: true
    },
});
module.exports = mongoose.model('Teacher', TeacherSchema );

<b-select id="schoolID" name="schoolID">
                <option selected>Select the school</option>
                <option v-for="school in schools" v-bind:value="school._id" v-bind:key="school._id">{{ school.name }}</option>
            </b-select>

以下是报名老师表格中的全文部分:

<script>

    import axios from 'axios'

    export default {
        name: 'register',
        data () {
            return {
                input: {
                    name: "",
                    email: "",
                    password: "",
                    schoolID: ""
                },
                schools: [],
                result : "",
                errors: []
            }
        },
        created() {
            axios.get('http://localhost:8081/public/school/list')
            .then(response => {
                this.schools = response.data
            })
            .catch(e => {
                this.errors.push(e)
            })
        },

        methods: {
            onSubmit (evt) {
                evt.preventDefault()
                if(this.input.name != "" && this.input.email != "" && this.input.password != "") {

                    axios.post('http://localhost:8081/api/auth/teacher/register', this.input)
                    .then(response => {
                        if (response.data.success == true){                            
                           console.log("teacheradded!")
                           this.result = "teacheraddded!"
                        }else{
                            console.log(response.data.msg)
                            this.errors.push(response.data.msg)
                        }
                    })
                    .catch(e => {
                        console.log(e.response)
                        this.errors.push(e)
                    })

                }
            }
        }
    }
</script>

这是教师/注册下的部分代码

router.post('/teacher/register', function(req, res) {
  if (!req.body.name || !req.body.email || !req.body.password) {
    res.json({success: false, msg: 'Please enter your name, email and password.'});
  } else {
    var newTeacher = new Teacher({
      schoolID: req.body.schoolID,
      name: req.body.name,
      email: req.body.email,
      password: req.body.password
    });
    // save the teacher
    newTeacher .save(function(err) {
      if (err) {
        console.log(err)
        return res.json({success: false, msg: 'Error'});
      }
      res.json({success: true, msg: 'Successfully created new teacher.'});
    });
  }
});

但我似乎无法得到学校的objectID,它被指定为select中的值。