Failure [INSTALL_FAILED_ALREADY_EXISTS] when i tried to update my applcation

Q:when I tried to update my applcation with new version that has same signature as previous one, shows above error.

A:If you install the application on your device via adb install you should look for the reinstall option which should be -r. So if you do adb install -r you should be able to install without uninstalling before.