Transactions

GORM perform single create, update, delete operations in transactions by default to ensure database data integrity.

If you want to treat multiple create, update, delete as one atomic operation, Transaction is made for that.

Transactions

To perform a set of operations within a transaction, the general flow is as below.

func CreateAnimals(db *gorm.DB) error {
  return db.Transaction(func(tx *gorm.DB) error {
    // do some database operations in the transaction (use 'tx' from this point, not 'db')
    if err := tx.Create(&Animal{Name: "Giraffe"}).Error; err != nil {
      // return any error will rollback
      return err
    }

    if err := tx.Create(&Animal{Name: "Lion"}).Error; err != nil {
      return err
    }

    // return nil will commit
    return nil
  })
}

Transactions by manual

// begin a transaction
tx := db.Begin()

// do some database operations in the transaction (use 'tx' from this point, not 'db')
tx.Create(...)

// ...

// rollback the transaction in case of error
tx.Rollback()

// Or commit the transaction
tx.Commit()

A Specific Example

func CreateAnimals(db *gorm.DB) error {
  // Note the use of tx as the database handle once you are within a transaction
  tx := db.Begin()
  defer func() {
    if r := recover(); r != nil {
      tx.Rollback()
    }
  }()

  if err := tx.Error; err != nil {
    return err
  }

  if err := tx.Create(&Animal{Name: "Giraffe"}).Error; err != nil {
     tx.Rollback()
     return err
  }

  if err := tx.Create(&Animal{Name: "Lion"}).Error; err != nil {
     tx.Rollback()
     return err
  }

  return tx.Commit().Error
}