When qualifying a column name and table name in the same statement, be sure to use the same qualifying expressions for each; they are evaluated as strings and must match; otherwise, an error is returned.
select demo.mary.publishers.city from demo.mary.publishers
city ----------------------- Boston Washington Berkeley
This example is incorrect because the syntax style for the column name does not match the syntax style used for the table name.
select demo.mary.publishers.city from demo..publishers
The column prefix "demo.mary.publishers" does not match a table name or alias name used in the query.