Implement 'QUARTER' in 'DATE_TRUNC'

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

@@ -458,6 +458,26 @@ public final class DateTimeFunctions {
             dateValue = DateTimeUtils.dateValue(year, month, 1);
             timeNanos = 0l;
             break;
+            
+        case QUARTER:
+            
+            long yearForQuarter = DateTimeUtils.yearFromDateValue(dateValue);
+            int monthForQuarter = DateTimeUtils.monthFromDateValue(dateValue);
+            
+            
+            if(monthForQuarter >= 10) {
+                monthForQuarter = 10;
+            }else if (monthForQuarter >= 7) {
+                monthForQuarter = 7;
+            }else if(monthForQuarter >= 4) {
+                monthForQuarter = 4;
+            }else {
+                monthForQuarter = 1;
+            }
+            
+            dateValue = DateTimeUtils.dateValue(yearForQuarter, monthForQuarter, 1);
+            timeNanos = 0l;
+            break;
 
         }
         if (timeNanos == null) {

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

@@ -719,19 +719,113 @@ SELECT DATE_TRUNC('month', '2015-05-29 15:14:13');
 SELECT DATE_TRUNC('MONTH', '2015-05-29 15:14:13');
 >> 2015-05-01 00:00:00
 
+SELECT DATE_TRUNC('month', '2015-05-01 15:14:13');
+>> 2015-05-01 00:00:00
+
+SELECT DATE_TRUNC('MONTH', '2015-05-01 15:14:13');
+>> 2015-05-01 00:00:00
 
 --
--- Test unhandled time unit
+-- Test time unit 'QUARTER'
 --
-SELECT DATE_TRUNC('---', '2015-05-29 15:14:13');
-> exception
+select DATE_TRUNC('quarter', time '00:00:00');
+>> 1970-01-01 00:00:00
+
+select DATE_TRUNC('QUARTER', time '00:00:00');
+>> 1970-01-01 00:00:00
+
+select DATE_TRUNC('quarter', time '15:14:13');
+>> 1970-01-01 00:00:00
+
+select DATE_TRUNC('QUARTER', time '15:14:13');
+>> 1970-01-01 00:00:00
+
+select DATE_TRUNC('quarter', date '2015-05-28');
+>> 2015-04-01 00:00:00
+
+select DATE_TRUNC('QUARTER', date '2015-05-28');
+>> 2015-04-01 00:00:00
+
+select DATE_TRUNC('quarter', timestamp '2015-05-29 15:14:13');
+>> 2015-04-01 00:00:00
+
+select DATE_TRUNC('QUARTER', timestamp '2015-05-29 15:14:13');
+>> 2015-04-01 00:00:00
+
+select DATE_TRUNC('quarter', timestamp with time zone '2015-05-29 15:14:13');
+>> 2015-04-01 00:00:00+00
+
+select DATE_TRUNC('QUARTER', timestamp with time zone '2015-05-29 15:14:13');
+>> 2015-04-01 00:00:00+00
+
+select DATE_TRUNC('quarter', timestamp with time zone '2015-05-29 05:14:13-06');
+>> 2015-04-01 00:00:00-06
+
+select DATE_TRUNC('QUARTER', timestamp with time zone '2015-05-29 05:14:13-06');
+>> 2015-04-01 00:00:00-06
+
+select DATE_TRUNC('quarter', timestamp with time zone '2015-05-29 15:14:13+10');
+>> 2015-04-01 00:00:00+10
+
+select DATE_TRUNC('QUARTER', timestamp with time zone '2015-05-29 15:14:13+10');
+>> 2015-04-01 00:00:00+10
+
+select DATE_TRUNC('quarter', '2015-05-29 15:14:13');
+>> 2015-04-01 00:00:00
+
+select DATE_TRUNC('QUARTER', '2015-05-29 15:14:13');
+>> 2015-04-01 00:00:00
+
+SELECT DATE_TRUNC('QUARTER', '2018-03-14 00:00:00.000');
+>> 2018-01-01 00:00:00
+
+SELECT DATE_TRUNC('quarter', '2018-03-14 00:00:00.000');
+>> 2018-01-01 00:00:00
 
 SELECT DATE_TRUNC('quarter', '2015-05-29 15:14:13');
-> exception
+>> 2015-04-01 00:00:00
 
 SELECT DATE_TRUNC('QUARTER', '2015-05-29 15:14:13');
+>> 2015-04-01 00:00:00
+
+SELECT DATE_TRUNC('quarter', '2015-05-01 15:14:13');
+>> 2015-04-01 00:00:00
+
+SELECT DATE_TRUNC('QUARTER', '2015-05-01 15:14:13');
+>> 2015-04-01 00:00:00
+
+SELECT DATE_TRUNC('quarter', '2015-07-29 15:14:13');
+>> 2015-07-01 00:00:00
+
+SELECT DATE_TRUNC('QUARTER', '2015-07-29 15:14:13');
+>> 2015-07-01 00:00:00
+
+SELECT DATE_TRUNC('quarter', '2015-09-29 15:14:13');
+>> 2015-07-01 00:00:00
+
+SELECT DATE_TRUNC('QUARTER', '2015-09-29 15:14:13');
+>> 2015-07-01 00:00:00
+
+SELECT DATE_TRUNC('quarter', '2015-10-29 15:14:13');
+>> 2015-10-01 00:00:00
+
+SELECT DATE_TRUNC('QUARTER', '2015-10-29 15:14:13');
+>> 2015-10-01 00:00:00
+
+SELECT DATE_TRUNC('quarter', '2015-12-29 15:14:13');
+>> 2015-10-01 00:00:00
+
+SELECT DATE_TRUNC('QUARTER', '2015-12-29 15:14:13');
+>> 2015-10-01 00:00:00
+
+--
+-- Test unhandled time unit
+--
+SELECT DATE_TRUNC('---', '2015-05-29 15:14:13');
 > exception
 
+
+
 SELECT DATE_TRUNC('year', '2015-05-29 15:14:13');
 > exception