Question: I want to uninstall mysql completely from ubuntu 20.04.
`sudo apt-get remove --purge mysql-server mysql-client mysql-common -y`

But every time got errors.

dpkg: error processing package mysql-server-8.0 (--remove):
package is in a very bad inconsistent state; you should
reinstall it before attempting a removal
dpkg: too many errors, stopping
Errors were encountered while processing:
mysql-server-8.0
Processing was halted because there were too many errors.
E: Sub-process /usr/bin/dpkg returned an error code (1)

I tried configuring dpkg `sudo dpkg --configure -a` , but again it says :

dpkg: error processing package mysql-server-8.0 (--configure):
package is in a very bad inconsistent state; you should
reinstall it before attempting configuration
Errors were encountered while processing:
mysql-server-8.0

Answer: 
I had the same challenge in `xubuntu 20.04`. This is what worked for me after several attempts.
I hope it helps someone in future.

1. list all files associated with mysql-server

```
sudo ls -l /var/lib/dpkg/info | grep -i mysql-server 

```

2. Remove the different file groups.

```
sudo rm -r /var/lib/dpkg/info/mysql-server-8.0.*
sudo rm -r /var/lib/dpkg/info/mysql-server-core-8.0.* 

```

3. Run

```
sudo apt update

```

Try reinstalling whatsoever you will trying to install.
The correct way to deal with such problem is to follow the instructions dpkg gives. One problem is that apt will refuse to act on such actions in those cases, so what you'd need to do is to `apt download` the required packages and reinstall them manually with `dpkg -i`.

After the packages have been reinstalled, then you can check whether the system is good again with `dpkg --audit`.