Rules for Columns Not Associated With an Explicit Table Name - Teradata Vantage NewSQL Engine - 16.20

Teradata Vantage™ Data Types and Literals

Teradata Database
Teradata Vantage NewSQL Engine
Programming Reference

If a column is not associated with an explicit table name, tables named in the SQL statement are searched, and one of the following occurs.

IF this … IS … THEN …
a matching column found in only one table the requested information is returned.
found in two or more tables an ambiguous column name error is reported.
not found the NAMED list is searched for the column name.

Named names are not valid when used to fully qualify a table name.

a column name not found in the SQL statement or in the NAMED list a nonexistent column error is reported.