How can I check for errors in CRUD operations using GORM?

Question

The official documentation for GORM demonstrates a way in which one can test for the existence of a record, i.e.:

user := User{Name: "Jinzhu", Age: 18, Birthday: time.Now()}  // returns true if record hasn’t been saved (primary key `Id` is blank) db.NewRecord(user) // => true  db.Create(&user)  // will return false after `user` created db.NewRecord(user) // => false 

This can be used to test indirectly for errors in record creation but reports no useful information in the event of a failure.

Having checked the source code for db.Create, there seems to be some sort of stack-frame inspection that checks for errors before proceeding, meaning that transactional errors will fail silently:

func Create(scope *Scope) {     defer scope.Trace(NowFunc())      if !scope.HasError() {         // actually perform the transaction     } } 

• Is this a bug, or am I missing something?
• How can/should I be informed of a failed transaction?
• Where can I get useful debugging information?

Answer 1

DB.Create() returns a new (cloned) gorm.DB which is a struct and has a field Error:

type DB struct {     Value        interface{}     Error        error     RowsAffected int64     // contains filtered or unexported fields } 

You can store the returned *gorm.DB value and check its DB.Error field like this:

if dbc := db.Create(&user); dbc.Error != nil {     // Create failed, do something e.g. return, panic etc.     return } 

If you don't need anything else from the returned gorm.DB, you can directly check its Error field:

if db.Create(&user).Error != nil {     // Create failed, do something e.g. return, panic etc.     return } 

Answer 2

I have tried the accepted answer, but it doesn't work, db.Error always return nil.

Just change something and it works, hope it helps somebody:

if err := db.Create(&Animal{Name: "Giraffe"}).Error; err != nil {    // Create failed, do something e.g. return, panic etc.    return  }