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. |