select_item ::=
 {function_name [(parameter_name [, parameter_name]...)]
 | NULL
 | numeric_literal
 | [schema_name .] {table_name | view_name} . *
 | [[schema_name .] {table_name . | view_name .}] column_name
 | sequence_name . {CURRVAL | NEXTVAL}
 | 'text'} 
 [[AS] alias]