无法使用golang从数据存储区中基于结构值获取记录

Question

I am writing a service for search functionality. when i am passing values in the body to get the specific record i am unable to get it based on the struct value. ex:phone number or username

Edit1:

type PatientData struct {
    ID            int64    datastore:"-"
    FirstName     string   json:"firstname,omitempty"
    LastName      string   json:"lastname,omitempty"
    UserName      string   json:"username,omitempty"
    Phone         string   json:"phone,omitempty"     
}

I want to get the full struct values based on Username or Phone. Below is my code:

func searchValue (res http.ResponseWriter, req *http.Request){

    log.Printf("%#v Getting values url - x ", "called search")

    patient := &PatientData{}
    if err := json.NewDecoder(req.Body).Decode(patient); err != nil {
        panic(err)
    }
    ctx := appengine.NewContext(req)
    ctx, err := appengine.Namespace(ctx, NAMESPACENAME)
    if err != nil {
        panic(err)
    }

    m := patient.Phone
    i, err := strconv.ParseInt(m, 10, 64)
    log.Printf("%#v Getting values m ", m)
    log.Printf("%#v Getting values url -yyy ",i)

    key := datastore.NewKey(ctx, "Patient","" , i, nil)
    log.Printf("%#v Getting values url - key ", key)
    err = datastore.Get(ctx, key, patient)
    if err := json.NewEncoder(res).Encode(patient); err != nil {
        panic(err)
    }

}

As i am passing PHONE in my Newkey i am unable to generate the values based on PHONE

I don't want to use Newkey in put functionality to generate a keyname and based on that KEYNAME i dont want to get Values.

Answer 1

datastore.Get() can only be used to get an entity from the datastore by its key, so its key must be known / present.

This is obviously not what you're trying to do. You are trying to fetch entities by properties which are not the key. To do that, you need to run a query.

Datastore queries are represented by the datastore.Query type. You need to create a query and set filters on it. In your case, you want to filter by the username and/or phone properties.

This is how it could look like. Fetch patient entities filtered by phone:

q :=  datastore.NewQuery("Patient").Filter("phone =", patient.Phone)

var patients []*Patient
keys, err := q.GetAll(ctx, &patients)
if err != nil {
    // Handle error
    return
}

// patients contains patients with the given phone number

An example fetching patients filtered by phone number AND user name:

q :=  datastore.NewQuery("Patient").
    Filter("phone =", patient.Phone).
    Filter("username =", patient.UserName)

var patients []*Patient
keys, err := q.GetAll(ctx, &patients)
if err != nil {
    // Handle error
    return
}

// patients contains patients with the given phone number and username