limit diff

sync.go

@@ -235,6 +235,15 @@ func (session *Session) SyncWithOptions(opts SyncOptions, beans ...interface{})
 				}
 			}
 
+			if oriIndex != nil && oriIndex.Type != index.Type {
+				sql := engine.dialect.DropIndexSQL(tbNameWithSchema, oriIndex)
+				_, err = session.exec(sql)
+				if err != nil {
+					return nil, err
+				}
+				oriIndex = nil
+			}
+
 			if oriIndex == nil {
 				addedNames[name] = index
 			}