If you want to install mariadb alongside mysql then you should follow this guide: https://mariadb.com/kb/en/mariadb/in...ongside-mysql/

In the meantime, however, you should remove mariadb. If that is not going to inconvenience you in the short-term (i.e. until you follow the above instructions and re-install it again), please post the output from dpkg -l *maria* so that we know which maria packages are installed and can be removed.

Thanks for the guidance.

The Screenshot of output is here-https://drive.google.com/open?id=0B-7ibsUXIE_oMWF3TGVjTVFTV00

Thanks. To remove mariadb:

sudo apt-get --purge autoremove mariadb-client-5.5 mariadb-common mariadb-galera-server mariadb-galera-server5.5 libmariadbclient18:amd64

Note that mariadb 5.5 will only be supported until April 2017 so it will be worthwhile you getting a later version anyway. Also, those mariadb packages you have are for Ubuntu 12.04 (Precise), not Ubuntu 14.04 (Trusty). It's important not to mix the distro versions of packages on your computer.

Thanks for the message.For now I installed a fresh version and it's up but wanted to know is the error that is shown is due to to the incompatible version with my os with the upgrade tries to install and flashes the error?

I have to admit that, with all due respect, I can't understand what you're saying here. Could you possibly rephrase it?

I was expecting you, in all honesty, to get back to me after removing the mariadb packages so that we could check that the removal had worked ok and to retest your package dependencies (which is very important), before you launched into following those instructions I gave you earlier for installing mariadb alongside mysql.

Thanks for the message.I meant I installed and my application is currently running fine as when earlier if I had removed the mariadb and reinstalled might be due to some dependency my application failed.I wanted to know the error (dpkg(1)) which was coming while running upgrade was it due to the presence of old or incompatible version which the os was trying to install?

Ah, good, I'm glad that it's running fine now. It's difficult to tell why exactly you had the problem, but having packages installed that were compiled for an earlier version of Ubuntu might certainly be one of the causes. The fact that you also wanted to install mariadb and mysql side-by-side may have also caused problems, particularly because mariadb provides mysql components as part of its install.

Did you in-place upgrade your system from Ubuntu 12.04 to 14.04 at some point? It's always useful if you do an upgrade like that to check any additional software that you've installed to see if you can get versions that were specifically compiled for the new version of Ubuntu that you're running.

But, more than that perhaps, it's useful to keep on top of updating. You should do a sudo apt-get update followed by a sudo apt-get upgrade (or their apt equivalents apt update and apt upgrade) on a regular basis and, unless you've intentionally held back packages, you should aim to end up with the magic line:

0 to upgrade, 0 to newly install, 0 to remove and 0 not to upgrade.

That way, your repository-tracked software is as up to date as it can be for the distro version in question. It means that your system therefore has less chance of getting itself in a tangle.

Thanks for the message.I wanted to know what exactly the difference is in sudo apt-dist-upgrade and sudo apt-upgrade.Also if there is a reales of new higher version will the same command update the version to latest

If you look at man apt-get, it explains the different apt-get commands in more detail.

apt-get upgrade compares your installed software versions against the versions listed in the repositories and upgrades all packages that have newer versions available. However, currently installed packages are never removed, and non-installed packages are never retrieved and installed. In essence, new versions of currently installed packages that cannot be upgraded without changing the install status of another package will not be upgraded. Normally, this works fine for the situation on your computer.

apt-get dist-upgrade is the same as apt-get upgrade, but it handles cases that are not as simple as the above. It manages the changing dependencies of new versions of packages using a conflict resolution system, attempting to upgrade more important packages at the expense of less important ones if necessary. Importantly, running apt-get dist-upgrade may actually remove some packages. So, this may have to be run on your system if the dependency situation is a bit more complicated. However, it should be used carefully.

There are other conflict resolution systems available. The aptitude package, for example, has one. But in the end, they are just trying to make intelligent decisions based on the dependencies that exist, and sometimes it doesn't work out. Hence, in your case, when apt-get dist-upgrade didn't work out (although it did have some success), the fall-back was to manually delete mariadb entirely (because we could see it was a known factor in the problem), get the system back into a stable state by running sudo apt-get upgrade (and sudo apt-get dist-upgrade if required), and then try re-installing mariadb to see if it was still problematic.

Note that, to do things correctly, sudo apt-get update should always be run before either sudo apt-get upgrade or sudo apt-get dist-upgrade, so that you are dealing with the most current information from the repositories as possible.

To summarise:

sudo apt-get update

sudo apt-get upgrade

If problems, decide according to the error message(s) what you will do next, but sudo apt-get dist-upgrade may be worth trying, or perhaps aptitude.

If a problem still exists, manually remove programs that appear to be causing problems and try to get the system into a stable state. Then, once sudo apt-get upgrade produces no problems, try installing programs again, one by one, to see where the real problem lies.

Thanks a lot for the useful information