Implement 'MILLENNIUM' in 'DATE_TRUNC'

h2/src/main/org/h2/expression/Function.java

@@ -107,7 +107,8 @@ public class Function extends Expression implements FunctionCall {
      * Pseudo functions for DATEADD, DATEDIFF, and EXTRACT.
      */
     public static final int MILLISECOND = 126, EPOCH = 127, MICROSECOND = 128, NANOSECOND = 129,
-            TIMEZONE_HOUR = 130, TIMEZONE_MINUTE = 131, DECADE = 132, CENTURY = 133;
+            TIMEZONE_HOUR = 130, TIMEZONE_MINUTE = 131, DECADE = 132, CENTURY = 133, 
+            MILLENNIUM = 134;
 
     public static final int DATABASE = 150, USER = 151, CURRENT_USER = 152,
             IDENTITY = 153, SCOPE_IDENTITY = 154, AUTOCOMMIT = 155,

h2/src/main/org/h2/util/DateTimeFunctions.java

@@ -26,6 +26,7 @@ import static org.h2.expression.Function.TIMEZONE_HOUR;
 import static org.h2.expression.Function.TIMEZONE_MINUTE;
 import static org.h2.expression.Function.WEEK;
 import static org.h2.expression.Function.YEAR;
+import static org.h2.expression.Function.MILLENNIUM;
 import java.math.BigDecimal;
 import java.text.DateFormatSymbols;
 import java.text.SimpleDateFormat;
@@ -107,6 +108,7 @@ public final class DateTimeFunctions {
         DATE_PART.put("TIMEZONE_MINUTE", TIMEZONE_MINUTE);
         DATE_PART.put("DECADE", DECADE);
         DATE_PART.put("CENTURY", CENTURY);
+        DATE_PART.put("MILLENNIUM", MILLENNIUM);
     }
 
     /**
@@ -503,7 +505,16 @@ public final class DateTimeFunctions {
             timeNanos = 0l;
             break;
 
+        case MILLENNIUM:
+
+            long yearForMillennium = DateTimeUtils.yearFromDateValue(dateValue);
+            yearForMillennium = (long) (Math.floor((yearForMillennium - 1) / 1000) * 1000) + 1;
+            dateValue = DateTimeUtils.dateValue(yearForMillennium, 1, 1);
+            timeNanos = 0l;
+            break;
+
         }
+        
         if (timeNanos == null) {
 
             // Return an exception in the timeUnit is not recognized

h2/src/test/org/h2/test/scripts/functions/timeanddate/date_trunc.sql

@@ -990,14 +990,84 @@ SELECT DATE_TRUNC('century', '2000-05-29 15:14:13');
 SELECT DATE_TRUNC('CENTURY', '2000-05-29 15:14:13');
 >> 1901-01-01 00:00:00
 
+SELECT DATE_TRUNC('century', '2001-05-29 15:14:13');
+>> 2001-01-01 00:00:00
+
+SELECT DATE_TRUNC('CENTURY', '2001-05-29 15:14:13');
+>> 2001-01-01 00:00:00
+
 --
--- Test unhandled time unit
+-- Test time unit 'MILLENNIUM'
+--
+select DATE_TRUNC('millennium', time '00:00:00');
+>> 1001-01-01 00:00:00
+
+select DATE_TRUNC('MILLENNIUM', time '00:00:00');
+>> 1001-01-01 00:00:00
+
+select DATE_TRUNC('millennium', time '15:14:13');
+>> 1001-01-01 00:00:00
+
+select DATE_TRUNC('MILLENNIUM', time '15:14:13');
+>> 1001-01-01 00:00:00
+
+select DATE_TRUNC('millennium', date '2015-05-28');
+>> 2001-01-01 00:00:00
+
+select DATE_TRUNC('MILLENNIUM', date '2015-05-28');
+>> 2001-01-01 00:00:00
+
+select DATE_TRUNC('millennium', timestamp '2015-05-29 15:14:13');
+>> 2001-01-01 00:00:00
+
+select DATE_TRUNC('MILLENNIUM', timestamp '2015-05-29 15:14:13');
+>> 2001-01-01 00:00:00
+
+select DATE_TRUNC('millennium', timestamp with time zone '2015-05-29 15:14:13');
+>> 2001-01-01 00:00:00+00
+
+select DATE_TRUNC('MILLENNIUM', timestamp with time zone '2015-05-29 15:14:13');
+>> 2001-01-01 00:00:00+00
+
+select DATE_TRUNC('millennium', timestamp with time zone '2015-05-29 05:14:13-06');
+>> 2001-01-01 00:00:00-06
+
+select DATE_TRUNC('MILLENNIUM', timestamp with time zone '2015-05-29 05:14:13-06');
+>> 2001-01-01 00:00:00-06
+
+select DATE_TRUNC('millennium', timestamp with time zone '2015-05-29 15:14:13+10');
+>> 2001-01-01 00:00:00+10
+
+select DATE_TRUNC('MILLENNIUM', timestamp with time zone '2015-05-29 15:14:13+10');
+>> 2001-01-01 00:00:00+10
+
+SELECT DATE_TRUNC('millennium', '2015-05-29 15:14:13');
+>> 2001-01-01 00:00:00
+
+SELECT DATE_TRUNC('MILLENNIUM', '2015-05-29 15:14:13');
+>> 2001-01-01 00:00:00
+
+SELECT DATE_TRUNC('millennium', '2001-05-29 15:14:13');
+>> 2001-01-01 00:00:00
+
+SELECT DATE_TRUNC('MILLENNIUM', '2001-05-29 15:14:13');
+>> 2001-01-01 00:00:00
+
+SELECT DATE_TRUNC('millennium', '2000-05-29 15:14:13');
+>> 1001-01-01 00:00:00
+
+SELECT DATE_TRUNC('MILLENNIUM', '2000-05-29 15:14:13');
+>> 1001-01-01 00:00:00
+
+--
+-- Test unhandled time unit and bad date
 --
 SELECT DATE_TRUNC('---', '2015-05-29 15:14:13');
 > exception
 
-SELECT DATE_TRUNC('millennium', '2015-05-29 15:14:13');
+SELECT DATE_TRUNC('', '2015-05-29 15:14:13');
 > exception
 
-SELECT DATE_TRUNC('MILLENNIUM', '2015-05-29 15:14:13');
+SELECT DATE_TRUNC('YEAR', '');
 > exception
+