Question

Is there a way with PostgreSQL to sort rows with NULL values in fields to the end of the selected table?

Like:

SELECT * FROM table ORDER BY somevalue, PUT_NULL_TO_END

Answer 1

NULL values are sorted last in default ascending order. You don’t have to do anything extra.

The issue applies to descending order, which is the perfect inverse and thus sorts NULL values on top.
PostgreSQL 8.3 introduced NULLS LAST:

ORDER BY somevalue DESC NULLS LAST

For PostgreSQL 8.2 and older or other RDBMS without this standard SQL feature:

ORDER BY (somevalue IS NULL), somevalue DESC

FALSE sorts before TRUE, so NULL values come last, just like in the example above.

See:

• Sort by column ASC, but NULL values first?
• The manual on SELECT