Apk file generating but white pages apppear and when after long time login page display but login system not wok

hello all ,am using ionic 3 and angular 4 for developing application …application without database work properly in my mobile .but when i added database to application …and after generating .apk file …in application white pages displays…and after 1 minutes of time when login page display…am not able to login (after click-on login not navigate to another page) …but application with database connectivity works well in browser
problem is with apk and ionic-devApp for testing purpose .

database use: mysql
backend :PHP slim framework

please help me to solve my problem