Disable Default Transaction

GORM perform write (create/update/delete) operations run inside a transaction to ensure data consistency, you can disable it during initialization if it is not required, you will gain about 30%+ performance improvement after that

  1. // Globally disable
  2. db, err := gorm.Open(sqlite.Open("gorm.db"), &gorm.Config{
  3.   SkipDefaultTransaction: true,
  4. })
  6. // Continuous session mode
  7. tx := db.Session(&Session{SkipDefaultTransaction: true})
  8. tx.First(&user, 1)
  9. tx.Find(&users)
  10. tx.Model(&user).Update("Age", 18)

Transaction

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

  1. db.Transaction(func(tx *gorm.DB) error {
  2.   // do some database operations in the transaction (use 'tx' from this point, not 'db')
  3.   if err := tx.Create(&Animal{Name: "Giraffe"}).Error; err != nil {
  4.     // return any error will rollback
  5.     return err
  6.   }
  8.   if err := tx.Create(&Animal{Name: "Lion"}).Error; err != nil {
  9.     return err
  10.   }
  12.   // return nil will commit the whole transaction
  13.   return nil
  14. })

Nested Transactions

GORM supports nested transactions, you can rollback a subset of operations performed within the scope of a larger transaction, for example:

  1. db.Transaction(func(tx *gorm.DB) error {
  2.   tx.Create(&user1)
  4.   tx.Transaction(func(tx2 *gorm.DB) error {
  5.     tx2.Create(&user2)
  6.     return errors.New("rollback user2") // Rollback user2
  7.   })
  9.   tx.Transaction(func(tx2 *gorm.DB) error {
  10.     tx2.Create(&user3)
  11.     return nil
  12.   })
  14.   return nil
  15. })
  17. // Commit user1, user3

Control the transaction manually

Gorm supports calling transaction control functions (commit / rollback) directly, for example:

  1. // begin a transaction
  2. tx := db.Begin()
  4. // do some database operations in the transaction (use 'tx' from this point, not 'db')
  5. tx.Create(...)
  7. // ...
  9. // rollback the transaction in case of error
  10. tx.Rollback()
  12. // Or commit the transaction
  13. tx.Commit()

A Specific Example

  1. func CreateAnimals(db *gorm.DB) error {
  2.   // Note the use of tx as the database handle once you are within a transaction
  3.   tx := db.Begin()
  4.   defer func() {
  5.     if r := recover(); r != nil {
  6.       tx.Rollback()
  7.     }
  8.   }()
  10.   if err := tx.Error; err != nil {
  11.     return err
  12.   }
  14.   if err := tx.Create(&Animal{Name: "Giraffe"}).Error; err != nil {
  15.      tx.Rollback()
  16.      return err
  17.   }
  19.   if err := tx.Create(&Animal{Name: "Lion"}).Error; err != nil {
  20.      tx.Rollback()
  21.      return err
  22.   }
  24.   return tx.Commit().Error
  25. }

SavePoint, RollbackTo

GORM provides SavePoint, RollbackTo to save points and roll back to a savepoint, for example:

  1. tx := db.Begin()
  2. tx.Create(&user1)
  4. tx.SavePoint("sp1")
  5. tx.Create(&user2)
  6. tx.RollbackTo("sp1") // Rollback user2
  8. tx.Commit() // Commit user1