| ERROR | ORDER BY item must be the number of a SELECT-list expression |
| CAUSE | A column alias was used in the ORDER BY clause of a SELECT statement that uses a UNION, INTERSECT, or MINUS set operator. This is not allowed. In such cases, expressions in the ORDER BY clause must be unsigned integers that designate the ordinal positions of select-list items. |
| ACTION | Change the alias in the ORDER BY clause to an unsigned integer that designates the ordinal position of the select item in question. |