Merge pull request #498 from yuanwhy/fix-round-function

Fix h2 ROUND

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

@@ -1234,7 +1234,11 @@ public class Function extends Expression implements FunctionCall {
             break;
         case ROUND: {
             double f = v1 == null ? 1. : Math.pow(10., v1.getDouble());
-            result = ValueDouble.get(Math.round(v0.getDouble() * f) / f);
+
+            double middleResult = v0.getDouble() * f;
+
+            int oneWithSymbol = middleResult > 0 ? 1 : -1;
+            result = ValueDouble.get(Math.round(Math.abs(middleResult)) / f * oneWithSymbol);
             break;
         }
         case TRUNCATE: {

h2/src/test/org/h2/test/db/TestFunctions.java

@@ -117,6 +117,7 @@ public class TestFunctions extends TestBase implements AggregateFunction {
         testThatCurrentTimestampStaysTheSameWithinATransaction();
         testThatCurrentTimestampUpdatesOutsideATransaction();
         testAnnotationProcessorsOutput();
+        testRound();
 
         deleteDb("functions");
     }
@@ -2010,6 +2011,28 @@ public class TestFunctions extends TestBase implements AggregateFunction {
         }
     }
 
+    private void testRound() throws SQLException {
+        deleteDb("functions");
+
+        Connection conn = getConnection("functions");
+        Statement stat = conn.createStatement();
+
+        final ResultSet rs = stat.executeQuery(
+                "select ROUND(-1.2), ROUND(-1.5), ROUND(-1.6), ROUND(2), ROUND(1.5), ROUND(1.8), ROUND(1.1) from dual");
+
+        rs.next();
+        assertEquals(-1, rs.getInt(1));
+        assertEquals(-2, rs.getInt(2));
+        assertEquals(-2, rs.getInt(3));
+        assertEquals(2, rs.getInt(4));
+        assertEquals(2, rs.getInt(5));
+        assertEquals(2, rs.getInt(6));
+        assertEquals(1, rs.getInt(7));
+
+        rs.close();
+        conn.close();
+    }
+
     private void testThatCurrentTimestampIsSane() throws SQLException,
             ParseException {
         deleteDb("functions");