Can I use… EXCEPT [DISTINCT] (table operator)

The table operator except [distinct] returns the rows of the first result except those that are also in the second.

SELECT …
  FROM …
EXCEPT DISTINCT
SELECT …
  FROM …

As with all table operators both sides of except must have the same number of columns and their types must be compatible based on their position (see corresponding). All null values are considered being the same (not distinct) for this operation.

If a row exists in the second result it will not appear in the final result—not even if it is multiple times in the first result.

Related

• except all

• Other table operators:

  • Union: union [distinct], union all

  • Intersect: intersect [distinct], intersect all

Normative References

The except [distinct] operator is defined in ISO/IEC 9075-2 as the mandatory feature T071-03, “EXCEPT DISTINCT table operator”.