In many places in the SQL syntax, you can represent the name of
a column by qualifying it with a table-Name or correlation-Name.
In some situations, you cannot qualify a column-Name with
a table-Name or a correlation-Name, but must use a Simple-column-Name instead.
Those situations are:
- creating a table ()
- specifying updatable columns in a cursor
- in a column's correlation name in a SELECT expression (see )
- in a column's correlation name in a TableExpression (see )
You cannot use correlation-Names for updatable columns; using correlation-Names
in this way will cause an SQL exception. For example:SELECT c11 AS col1, c12 AS col2, c13 FROM t1 FOR UPDATE of c11,c13
In this example, the correlation-Name col1 FOR c11 is
not permitted because c11 is listed in the FOR UPDATE list
of columns. You can use the correlation-Name FOR c12 because
it is not in the FOR UPDATE list.
Syntax [ { table-Name | correlation-Name } . ] SQL92Identifier
Example -- C.Country is a column-Name qualified with a
-- correlation-Name.
SELECT C.Country
FROM APP.Countries C