Create

Create Record

user := User{Name: "Jinzhu", Age: 18, Birthday: time.Now()}

db.NewRecord(user) // => returns `true` as primary key is blank

db.Create(&user)

db.NewRecord(user) // => return `false` after `user` created

Default Values

You can define a field’s default value with a tag. For example:

type Animal struct {
  ID   int64
  Name string `gorm:"default:'galeone'"`
  Age  int64
}

Then the inserting SQL will exclude those fields that have no value or zero values. After inserting the record into the database, gorm will load those fields’ value from the database.

var animal = Animal{Age: 99, Name: ""}
db.Create(&animal)
// INSERT INTO animals("age") values('99');
// SELECT name from animals WHERE ID=111; // the returning primary key is 111
// animal.Name => 'galeone'

NOTE all fields having a zero value, like 0, '', false or other zero values, won’t be saved into the database but will use its default value. If you want to avoid this, consider using a pointer type or scanner/valuer, e.g:

// Use pointer value
type User struct {
  gorm.Model
  Name string
  Age  *int `gorm:"default:18"`
}

// Use scanner/valuer
type User struct {
  gorm.Model
  Name string
  Age  sql.NullInt64 `gorm:"default:18"`
}

Setting Field Values In Hooks

If you want to update a field’s value in BeforeCreate hook, you can use scope.SetColumn, for example:

func (user *User) BeforeCreate(scope *gorm.Scope) error {
  scope.SetColumn("ID", uuid.New())
  return nil
}

Extra Creating option

// Add extra SQL option for inserting SQL
db.Set("gorm:insert_option", "ON CONFLICT").Create(&product)
// INSERT INTO products (name, code) VALUES ("name", "code") ON CONFLICT;