package main import ( "time" "github.com/go-rel/rel" "github.com/go-rel/rel/adapter/mysql" "github.com/go-rel/changeset" "github.com/go-rel/changeset/params" ) type Product struct { ID int Name string Price int CreatedAt time.Time UpdatedAt time.Time } // ChangeProduct prepares data before database operation. // Such as casting value to appropriate types and perform validations. func ChangeProduct(product interface{}, params params.Params) *changeset.Changeset { ch := changeset.Cast(product, params, []string{"name", "price"}) changeset.ValidateRequired(ch, []string{"name", "price"}) changeset.ValidateMin(ch, "price", 100) return ch } func main() { // initialize mysql adapter. adapter, _ := mysql.Open(dsn) defer adapter.Close() // initialize rel's repo. repo := rel.New(adapter) var product Product // Inserting Products. // Changeset is used when creating or updating your data. ch := ChangeProduct(product, params.Map{ "name": "shampoo", "price": 1000,	}) if ch.Error() != nil { // handle error	} // Changeset can also be created directly from json string. jsonch := ChangeProduct(product, params.ParseJSON(`{ "name": "soap", "price": 2000, }`)) // Create products with changeset and return the result to &product, if err := repo.Insert(context.TODO(), &product, ch); err != nil { // handle error	} }