I have entities as bellow:
type Data struct {
Receiver string `json:"receiver"`
Status string `json:"status"`
Alerts alerts `json:"alerts" gorm:"foreignKey"`
}
type Alert struct {
Status string `json:"status"`
}
type alerts []Alert
func (sla *alerts) Scan(src interface{}) error {
return json.Unmarshal(src.([]byte), &sla)
}
func (sla alerts) Value() (driver.Value, error) {
val, err := json.Marshal(sla)
return string(val), err
}
and the migration is as bellow: db.AutoMigrate(apiV1.Data{}, apiV1.Alert{})
but when I try to put some value to data table. but it act as a text with Alerts.
so I can't query on alerts. also alert table is empty.
Related
I am trying to save an hederea contract ID of type *hedera.ContractID into a Gorm field but i get the error "invalid field found for struct github.com/hashgraph/hedera-sdk-go/v2.AccountID's field AliasKey: define a valid foreign key for relations or implement the Valuer interface"
package contract
import (
"fmt"
"github.com/.../scanner/controllers/blockchain"
database "github.com/.../scanner/db"
model "github.com/.../scanner/models"
"github.com/rs/xid"
"gorm.io/gorm"
)
func DeployContract() *gorm.DB {
//connect to database
db, err := database.ConnectToDB()
//if db connection fails
if err != nil {
panic(err)
}
//init model
var modelContract model.Contract
//check if a contract has been deployed
if err := db.First(&modelContract); err.Error != nil {
//no deployment found
//Migrate the schema
db.AutoMigrate(&model.Contract{})
//deploy contract
contract, _ := blockchain.DeployContract()
//create record
// generate random id
id := xid.New()
// Create
db.Create(&model.Contract{
Id: id.String(),
ContractId: contract.Receipt.ContractID,
GasUsed: contract.CallResult.GasUsed,
TransactionId: fmt.Sprint(contract.TransactionID),
Timestamp: contract.ConsensusTimestamp,
ChargeFee: fmt.Sprint(contract.TransactionFee),
PayerAccount: fmt.Sprint(contract.TransactionID.AccountID),
Status: fmt.Sprint(contract.Receipt.Status),
})
}
return db
}
Gorm Model
package models
import (
"time"
"github.com/hashgraph/hedera-sdk-go/v2"
"gorm.io/gorm"
)
type Contract struct {
gorm.Model
Id string
ContractId *hedera.ContractID
GasUsed uint64
TransactionId string
Timestamp time.Time
ChargeFee string
PayerAccount string
Status string
}
For custom data types, you need to specify how the value will be stored and retrieved from your database. This is done by implementing the Scanner and Valuer interfaces.
However, since hedera.ContractID is defined in another package, you will need to create your own ContractID and implement these interfaces. Something like this:
type ContractID hedera.ContractID
type Contract struct {
gorm.Model
Id string
ContractId *ContractID
GasUsed uint64
TransactionId string
Timestamp time.Time
ChargeFee string
PayerAccount string
Status string
}
func (c *ContractID) Scan(value interface{}) error {
bytes, ok := value.([]byte)
if !ok {
return errors.New(fmt.Sprint("Failed to unmarshal ContractID value:", value))
}
return json.Unmarshal(bytes, c)
}
func (c ContractID) Value() (driver.Value, error) {
return json.Marshal(c)
}
Additionally, cast hedera.ContractID into model.ContractID wherever it is used. For example:
cID := model.ContractID(*contract.Receipt.ContractID)
// Create
db.Create(&model.Contract{
Id: id.String(),
ContractId: &cID,
GasUsed: contract.CallResult.GasUsed,
TransactionId: fmt.Sprint(contract.TransactionID),
Timestamp: contract.ConsensusTimestamp,
ChargeFee: fmt.Sprint(contract.TransactionFee),
PayerAccount: fmt.Sprint(contract.TransactionID.AccountID),
Status: fmt.Sprint(contract.Receipt.Status),
})
I am fetching some data from MYSQL database.. Using query data is getting correclty (eg 10 rows)
I want to bind into a list of model for displaying.
But panic error displaying
type UserDetails []UserDetail
type UserDetail struct {
id string `json:"id" boil:",bind"`
ScreenName string `json:"screenName" boil:",bind" `
}
func (m *mysqlStore) GetUsersDetails(ctx context.Context) () {
var userDetails []*models.UserDetail
err := queries.Raw(`
SELECT
user.id,
user.screen_name
FROM user
group by user.id
`).Bind(ctx, m.db, &userDetails)
if err != nil {
fmt.Println(err)
}
fmt.Println(userDetails)
}
here using the MYSQLQuery i am getting the correct data. I want to display that in a list of arrary eg:
[
{"id":"1",
"screenName":"test"},
{"id":"2",
"screenName":"test"}
]
what is the issue in my go code?
I got the Answer
In this case struct must be
type UserDetail struct {
id string `json:"id"`
ScreenName string `json:"screenName"`
}
and
var userDetails []models.UserDetail
I was trying to make a rest API for user registration and on that api there is a field named "gender", so I'm receiving that field as Struct but on user table there is no field for "gender". Is it possible to skip that "gender" field from struct while inserting with gorm?
This is my DataModel
package DataModels
type User struct {
Id uint `json:"id"`
Otp int `json:"otp"`
UserId string `json:"user_id"`
UserType string `json:"user_type"`
FullName string `json:"full_name"`
MobileNo string `json:"mobile"`
Email string `json:"email"`
Gender string `json:"gender"` // I want to skip this filed while inserting to users table
Password string `json:"password"`
}
func (b *User) TableName() string {
return "users"
}
This my Controller Function
func CreateUser(c *gin.Context) {
var user Models.User
_ = c.BindJSON(&user)
err := Models.CreateUser(&user) // want to skip that gender filed while inserting
if err != nil {
fmt.Println(err.Error())
c.AbortWithStatus(http.StatusNotFound)
} else {
c.JSON(http.StatusOK, user)
}
}
This is my model function for inserting
func CreateUser(user *User) (err error) {
if err = Config.DB.Create(user).Error; err != nil {
return err
}
return nil
}
GORM allows you to ignore the field with tag, use gorm:"-" to ignore the field
type User struct {
...
Gender string `json:"gender" gorm:"-"` // ignore this field when write and read
}
Offical doc details about Field-Level Permission
Eklavyas Answer is omitting gender always, not just on Create.
If I am correct you want to Skip the Gender field within the Registration. You can use Omit for that.
db.Omit("Gender").Create(&user)
I've got some REST API with my models defined as Go structs.
type User struct {
FirstName string
LastName string
}
Then I've got my database methods for getting data.
GetUserByID(id int) (*User, error)
Now I'd like to replace my REST API with https://github.com/twitchtv/twirp .
Therefore I started defining my models inside .proto files.
message User {
string first_name = 2;
string last_name = 3;
}
Now I've got two User types. Let's call them the native and the proto type.
I've also got a service defined in my .proto file which returns a user to the frontend.
service Users {
rpc GetUser(Id) returns (User);
}
This generates an interface that I have to fill in.
func (s *Server) GetUser(context.Context, id) (*User, error) {
// i'd like to reuse my existing database methods
u, err := db.GetUserByID(id)
// handle error
// do more stuff
return u, nil
}
Unfortunately this does not work. My database returns a native User but the interface requires a proto user.
Is there an easy way to make it work? Maybe using type aliases?
Thanks a lot!
One way you can solve your problem is by doing the conversion manually.
type User struct {
FirstName string
LastName string
}
type protoUser struct {
firstName string
lastName string
}
func main() {
u := db() // Retrieve a user from a mocked db
fmt.Println("Before:")
fmt.Printf("%#v\n", *u) // What db returns (*protoUser)
fmt.Println("After:")
fmt.Printf("%#v\n", u.AsUser()) // What conversion returns (User)
}
// Mocked db that returns pointer to protoUser
func db() *protoUser {
pu := protoUser{"John", "Dough"}
return &pu
}
// Conversion method (converts protoUser into a User)
func (pu *protoUser) AsUser() User {
return User{pu.firstName, pu.lastName}
}
The key part is the AsUser method on the protoUser struct.
There we simply write our custom logic for converting a protoUser into a User type we want to be working with.
Working Example
As #Peter mentioned in the comment section.
I've seen a project which made it with a custom Convert function. It converts the Protobuf to local struct via json.Unmarshal, not sure how's the performance but it's a way to go.
Preview Code PLAYGROUND
// Convert converts the in struct to out struct via `json.Unmarshal`
func Convert(in interface{}, out interface{}) error {
j, err := json.Marshal(in)
if err != nil {
return err
}
err = json.Unmarshal(j, &out)
if err != nil {
return err
}
return nil
}
func main() {
// Converts the protobuf struct to local struct via json.Unmarshal
var localUser User
if err := convert(protoUser, &localUser); err != nil {
panic(err)
}
}
Output
Before:
main.ProtoUser{FirstName:"John", LastName:"Dough"}
After:
main.User{FirstName:"John", LastName:"Dough"}
Program exited.
I am quite new to Go and I would like to startup by setting a GIN-GONIC API. I found this tutorial and I am very happy with that skeleton. But now I am stuck with the validating process which I added: "gopkg.in/validator.v2" and
type Todo struct {
gorm.Model
Title string `json:"title"`
Completed int `json:"completed"`
}
became
type Todo struct {
gorm.Model
Title string `json:"title" **validate:"size:2"**`
Completed int `json:"completed"`
}
and then in the CreateTodo function which I added :
if errs := validator.Validate(todo); errs!=nil {
c.JSON(500, gin.H{"Error": errs.Error()})
}
but then a POST call send :
"Error": "Type: unknown tag"
after some research I found that :
Using a non-existing validation func in a field tag will always return false and with error validate.ErrUnknownTag.
so the **validate:"size:2"** must be wrong ...
I don't get how to set the validation and also how to display the correct error within the "catch":
c.JSON(500, gin.H{"Error": errs.Error()})
Looks like you haven't defined size validation function. Also you can do it.
Custom validation functions:
func size(v interface{}, param int) error {
st := reflect.ValueOf(v)
if st.Kind() != reflect.String {
return validate.ErrUnsupported
}
if utf8.RuneCountInString(st.String()) != param {
return errors.New("Wrong size")
}
return nil
}
validate.SetValidationFunc("size", size)