How To Drop Primary Key By Specifying Column Only?

I checked column from xsd file which created from DataBase.

And before installing my application I will check any column in destination base whether have complete column or not.

 

And if there is any column which is not wanted column(not same as xsd structure)

I will delete it by creating sql command as follow "ALTER TABLE tableName DROP COLUMN column1, column2, ......"

and Execute it by program initialization.

 

So

I need delete it by run-time

 

 

However some column may be Primary Key with any reason

 

That's why I can't delete them by simple command

 

I expect to delete them by specific column instead of specific constraint name which is not sure name.

 

 

Please advise me....