diff --git a/interface.go b/interface.go
index 26c962ac..87d00489 100644
--- a/interface.go
+++ b/interface.go
@@ -4,7 +4,7 @@ import (
 	"database/sql"
 )
 
-type sqlCommon interface {
+type SqlCommon interface {
 	Exec(query string, args ...interface{}) (sql.Result, error)
 	Prepare(query string) (*sql.Stmt, error)
 	Query(query string, args ...interface{}) (*sql.Rows, error)
@@ -25,9 +25,11 @@ type Database interface {
 	DB() *sql.DB
 	New() Database
 	NewScope(value interface{}) *Scope
-	CommonDB() sqlCommon
-	Callback() *callback
-	SetLogger(l logger)
+
+	CommonDB() SqlCommon
+	//Callback() *callback
+	//SetLogger(l logger)
+
 	LogMode(enable bool) Database
 	SingularTable(enable bool)
 
diff --git a/main.go b/main.go
index 606d6b6f..61e9c533 100644
--- a/main.go
+++ b/main.go
@@ -24,7 +24,7 @@ type DB struct {
 	Error             error
 	RowsAffected      int64
 	callback          *callback
-	db                sqlCommon
+	db                SqlCommon
 	parent            *DB
 	search            *search
 	logMode           int
@@ -44,7 +44,7 @@ func Open(dialect string, args ...interface{}) (DB, error) {
 		err = errors.New("invalid database source")
 	} else {
 		var source string
-		var dbSql sqlCommon
+		var dbSql SqlCommon
 
 		switch value := args[0].(type) {
 		case string:
@@ -59,7 +59,7 @@ func Open(dialect string, args ...interface{}) (DB, error) {
 				driver = "postgres" // FoundationDB speaks a postgres-compatible protocol.
 			}
 			dbSql, err = sql.Open(driver, source)
-		case sqlCommon:
+		case SqlCommon:
 			source = reflect.Indirect(reflect.ValueOf(value)).FieldByName("dsn").String()
 			dbSql = value
 		}
@@ -107,7 +107,7 @@ func (db *DB) NewScope(value interface{}) *Scope {
 // CommonDB Return the underlying sql.DB or sql.Tx instance.
 // Use of this method is discouraged. It's mainly intended to allow
 // coexistence with legacy non-GORM code.
-func (s *DB) CommonDB() sqlCommon {
+func (s *DB) CommonDB() SqlCommon {
 	return s.db
 }
 
@@ -338,7 +338,7 @@ func (s *DB) Begin() Database {
 	c := s.clone()
 	if db, ok := c.db.(sqlDb); ok {
 		tx, err := db.Begin()
-		c.db = interface{}(tx).(sqlCommon)
+		c.db = interface{}(tx).(SqlCommon)
 		c.AddError(err)
 	} else {
 		c.AddError(CantStartTransaction)
diff --git a/scope.go b/scope.go
index ad12c5f2..4ad78532 100644
--- a/scope.go
+++ b/scope.go
@@ -66,7 +66,7 @@ func (scope *Scope) DB() *DB {
 }
 
 // SqlDB return *sql.DB
-func (scope *Scope) SqlDB() sqlCommon {
+func (scope *Scope) SqlDB() SqlCommon {
 	return scope.db.db
 }
 
@@ -366,7 +366,7 @@ func (scope *Scope) Trace(t time.Time) {
 func (scope *Scope) Begin() *Scope {
 	if db, ok := scope.SqlDB().(sqlDb); ok {
 		if tx, err := db.Begin(); err == nil {
-			scope.db.db = interface{}(tx).(sqlCommon)
+			scope.db.db = interface{}(tx).(SqlCommon)
 			scope.InstanceSet("gorm:started_transaction", true)
 		}
 	}