Support MySQL5.7 in backward compatible mode (#630)

database/database.sql

@@ -1,4 +1,7 @@
 -- >> This file is autogenerated from tables.sql and constraints.sql. Do not modify directly << --
+-- Disable ONLY_FULL_GROUP_BY required by MySQL 5.7
+SET GLOBAL sql_mode=(SELECT REPLACE(@@sql_mode,'ONLY_FULL_GROUP_BY',''));
+
 --
 -- Table structure for table `ospos_app_config`
 --