Change return type to an interface

dbmap.go

@@ -24,7 +24,7 @@ import (
 type DbIM interface {
 	GetDb() *sql.DB
 	GetDbx() *sqlx.DB
-	NewDbMap(db *sql.DB, dialect Dialect) DbIM
+	NewDbMap(db *sql.DB, dialect Dialect) *DbIM
 	TraceOn(prefix string, logger *log.Logger)
 	TraceOff()
 	AddTable(i interface{}, name ...string) *TableMap
@@ -80,7 +80,7 @@ type DbMap struct {
 }
 
 // NewDbMap returns a new DbMap using the db connection and dialect
-func NewDbMap(db *sql.DB, dialect Dialect) *DbMap {
+func NewDbMap(db *sql.DB, dialect Dialect) *DbIM {
 	return &DbMap{Db: db, Dialect: dialect, Dbx: sqlx.NewDb(db, dialect.DriverName())}
 }