Database Errors:An error is said to have occurred if the implementation of a command to manipulate the database cannot be successfully finished either due to inconsistent data or because of state of program.  For instance, there may be a command in program to kept data in database.  On the implementation of command, it is found that there is no place / space in database to accommodate that additional data.  Then it can be said that an error has happened.  This error is because of  the physical state of database storage.