text: Title: Schema autogeneration from SQL complains about missing primary keys in tables one at a time
  Body: Related to #649. Assume multiple tables in a database are missing primary keys, and the user is attempting to autogenerate a schema from that database.
  
  The `MissingPrimaryKeyError` that will get raised will contain the information of only a single table that is missing a primary key. That means that the user will end up re-running the autogeneration process N times to discover N tables with missing primary keys, which is incredibly inconvenient.
  
  The error message should contain all the problematic tables with missing primary keys, so the user can avoid all of them in one go.