Polish: use isEmpty() to check whether the collection is empty or not.

Convert constraint type into enum

Avoid resource leak

Reimplement DATEADD without a Calendar and fix some incompatibilities

Do not write each SQL error multiple times in TestScript

Improve test stability

Fix TestDateTimeUtils.testDayOfWeek() and example with ANY(?)

Reimplement DATEDIFF without a Calendar

Add support for = ANY(?)

Allow to read invalid February 29 dates with LocalDate as March 1