DRILL-5002: Using hive's date functions on top of date column gives w…

…rong results for local time-zone

closes #937

contrib/storage-hive/core/src/main/codegen/templates/ObjectInspectorHelper.java

@@ -204,7 +204,11 @@ public static JBlock getDrillObject(JCodeModel m, ObjectInspector oi,
           <#elseif entry.hiveType == "TIMESTAMP">
             JVar tsVar = jc._else().decl(m.directClass(java.sql.Timestamp.class.getCanonicalName()), "ts",
               castedOI.invoke("getPrimitiveJavaObject").arg(returnValue));
-            jc._else().assign(returnValueHolder.ref("value"), tsVar.invoke("getTime"));
+            // Bringing relative timestamp value without timezone info to timestamp value in UTC, since Drill keeps date-time values in UTC
+            JVar localDateTimeVar = jc._else().decl(m.directClass(org.joda.time.LocalDateTime.class.getCanonicalName()), "localDateTime",
+                JExpr._new(m.directClass(org.joda.time.LocalDateTime.class.getCanonicalName())).arg(tsVar));
+            jc._else().assign(returnValueHolder.ref("value"), localDateTimeVar.invoke("toDateTime")
+                .arg(m.directClass(org.joda.time.DateTimeZone.class.getCanonicalName()).staticRef("UTC")).invoke("getMillis"));
           <#elseif entry.hiveType == "DATE">
             JVar dVar = jc._else().decl(m.directClass(java.sql.Date.class.getCanonicalName()), "d",
               castedOI.invoke("getPrimitiveJavaObject").arg(returnValue));

contrib/storage-hive/core/src/main/codegen/templates/ObjectInspectors.java

@@ -213,7 +213,10 @@ public java.sql.Timestamp getPrimitiveJavaObject(Object o){
     <#else>
       final TimeStampHolder h = (TimeStampHolder) o;
     </#if>
-      return new java.sql.Timestamp(h.value);
+      org.joda.time.LocalDateTime dateTime = new org.joda.time.LocalDateTime(h.value, org.joda.time.DateTimeZone.UTC);
+      // use "toDate()" to get java.util.Date object with exactly the same fields as this Joda date-time.
+      // See more in Javadoc for "LocalDateTime#toDate()"
+      return new java.sql.Timestamp(dateTime.toDate().getTime());
     }
 
     @Override
@@ -226,7 +229,10 @@ public TimestampWritable getPrimitiveWritableObject(Object o) {
     <#else>
       final TimeStampHolder h = (TimeStampHolder) o;
     </#if>
-      return new TimestampWritable(new java.sql.Timestamp(h.value));
+      org.joda.time.LocalDateTime dateTime = new org.joda.time.LocalDateTime(h.value, org.joda.time.DateTimeZone.UTC);
+      // use "toDate()" to get java.util.Date object with exactly the same fields as this Joda date-time.
+      // See more in Javadoc for "LocalDateTime#toDate()"
+      return new TimestampWritable(new java.sql.Timestamp(dateTime.toDate().getTime()));
     }
 
 <#elseif entry.drillType == "Date">
@@ -240,7 +246,10 @@ public java.sql.Date getPrimitiveJavaObject(Object o){
     <#else>
       final DateHolder h = (DateHolder) o;
     </#if>
-      return new java.sql.Date(h.value);
+      org.joda.time.LocalDate localDate = new org.joda.time.LocalDate(h.value, org.joda.time.DateTimeZone.UTC);
+      // Use "toDate()" to get java.util.Date object with exactly the same year the same year, month and day as Joda date.
+      // See more in Javadoc for "LocalDate#toDate()"
+      return new java.sql.Date(localDate.toDate().getTime());
     }
 
     @Override
@@ -253,7 +262,10 @@ public DateWritable getPrimitiveWritableObject(Object o) {
     <#else>
       final DateHolder h = (DateHolder) o;
     </#if>
-      return new DateWritable(new java.sql.Date(h.value));
+      org.joda.time.LocalDate localDate = new org.joda.time.LocalDate(h.value, org.joda.time.DateTimeZone.UTC);
+      // Use "toDate()" to get java.util.Date object with exactly the same year the same year, month and day as Joda date.
+      // See more in Javadoc for "LocalDate#toDate()"
+      return new DateWritable(new java.sql.Date(localDate.toDate().getTime()));
     }
 
 <#else>

contrib/storage-hive/core/src/test/java/org/apache/drill/exec/fn/hive/TestInbuiltHiveUDFs.java

@@ -1,4 +1,4 @@
-/**
+/*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
@@ -26,6 +26,7 @@
 import org.apache.drill.exec.compile.ClassTransformer;
 import org.apache.drill.exec.hive.HiveTestBase;
 import org.apache.drill.exec.server.options.OptionValue;
+import org.joda.time.DateTime;
 import org.junit.Test;
 
 import java.util.List;
@@ -138,4 +139,44 @@ public void testEmbeddedHiveFunctionCall() throws Exception {
     }
   }
 
+  @Test
+  public void testLastDay() throws Exception {
+    testBuilder()
+        .sqlQuery("select last_day(to_date('1994-02-01','yyyy-MM-dd')) as `LAST_DAY` from (VALUES(1))")
+        .unOrdered()
+        .baselineColumns("LAST_DAY")
+        .baselineValues("1994-02-28")
+        .go();
+  }
+
+  @Test
+  public void testDatediff() throws Exception {
+    testBuilder()
+        .sqlQuery("select datediff(date '1996-03-01', timestamp '1997-02-10 17:32:00.0') as `DATEDIFF` from (VALUES(1))")
+        .unOrdered()
+        .baselineColumns("DATEDIFF")
+        .baselineValues(-346)
+        .go();
+  }
+
+  @Test
+  public void testFromUTCTimestamp() throws Exception {
+    testBuilder()
+        .sqlQuery("select from_utc_timestamp('1970-01-01 08:00:00','PST') as PST_TIMESTAMP from (VALUES(1))")
+        .unOrdered()
+        .baselineColumns("PST_TIMESTAMP")
+        .baselineValues(DateTime.parse("1970-01-01T00:00:00.0"))
+        .go();
+  }
+
+  @Test
+  public void testToUTCTimestamp() throws Exception {
+    testBuilder()
+        .sqlQuery("select to_utc_timestamp('1970-01-01 00:00:00','PST') as UTC_TIMESTAMP from (VALUES(1))")
+        .unOrdered()
+        .baselineColumns("UTC_TIMESTAMP")
+        .baselineValues(DateTime.parse("1970-01-01T08:00:00.0"))
+        .go();
+  }
+
 }