database

type DeadlockError interface {
	IsDeadlock() bool
}

type DuplicatedError interface {
	IsDuplicated() bool
}

type LockMode int

type NotFoundError interface {
	IsNotFound() bool
}

type Queryer interface {
	Query(func(*sql.Tx) error) error
}

type Transaction interface {
	Queryer
	// Begin starts this transactoin. Begin should start a new fresh transaction if it
	// is called on an already finished (committed or rollbacked) transaction.
	Begin() error
	Commit() error
	Rollback() error
	// Error returns the last TransactionError, if any, that was encountered during
	// query and commit processes.
	Error() TransactionError
}

type TransactionError interface {
	error
	DeadlockError
	NotFoundError
	DuplicatedError
}

type TransactionManager interface {
	NewTransaction() Transaction
}