[SPARK-27898][SQL] Support 4 date operators(date + integer, integer + date, date - integer and date - date)

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/TypeCoercion.scala

@@ -820,8 +820,10 @@ object TypeCoercion {
   }
 
   /**
-   * Turns Add/Subtract of DateType/TimestampType/StringType and CalendarIntervalType
-   * to TimeAdd/TimeSub
+   * 1. Turns Add/Subtract of DateType/TimestampType/StringType and CalendarIntervalType
+   *    to TimeAdd/TimeSub.
+   * 2. Turns Add/Subtract of DateType/IntegerType and IntegerType/DateType
+   *    to DateAdd/DateSub/DateDiff.
    */
   object DateTimeOperations extends Rule[LogicalPlan] {
 
@@ -837,6 +839,11 @@ object TypeCoercion {
         Cast(TimeAdd(l, r), l.dataType)
       case Subtract(l, r @ CalendarIntervalType()) if acceptedTypes.contains(l.dataType) =>
         Cast(TimeSub(l, r), l.dataType)
+
+      case Add(l @ DateType(), r @ IntegerType()) => DateAdd(l, r)
+      case Add(l @ IntegerType(), r @ DateType()) => DateAdd(r, l)
+      case Subtract(l @ DateType(), r @ IntegerType()) => DateSub(l, r)
+      case Subtract(l @ DateType(), r @ DateType()) => DateDiff(l, r)
     }
   }
 

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/TypeCoercionSuite.scala

@@ -1406,6 +1406,7 @@ class TypeCoercionSuite extends AnalysisTest {
     val timestamp = Literal(new Timestamp(0L))
     val interval = Literal(new CalendarInterval(0, 0))
     val str = Literal("2015-01-01")
+    val intValue = Literal(0, IntegerType)
 
     ruleTest(dateTimeOperations, Add(date, interval), Cast(TimeAdd(date, interval), DateType))
     ruleTest(dateTimeOperations, Add(interval, date), Cast(TimeAdd(date, interval), DateType))
@@ -1424,6 +1425,11 @@ class TypeCoercionSuite extends AnalysisTest {
     // interval operations should not be effected
     ruleTest(dateTimeOperations, Add(interval, interval), Add(interval, interval))
     ruleTest(dateTimeOperations, Subtract(interval, interval), Subtract(interval, interval))
+
+    ruleTest(dateTimeOperations, Add(date, intValue), DateAdd(date, intValue))
+    ruleTest(dateTimeOperations, Add(intValue, date), DateAdd(date, intValue))
+    ruleTest(dateTimeOperations, Subtract(date, intValue), DateSub(date, intValue))
+    ruleTest(dateTimeOperations, Subtract(date, date), DateDiff(date, date))
   }
 
   /**

sql/core/src/test/resources/sql-tests/inputs/datetime.sql

@@ -28,4 +28,9 @@ select a, b from ttf2 order by a, current_date;
 
 select weekday('2007-02-03'), weekday('2009-07-30'), weekday('2017-05-27'), weekday(null), weekday('1582-10-15 13:10:15');
 
-select year('1500-01-01'), month('1500-01-01'), dayOfYear('1500-01-01');
+select year('1500-01-01'), month('1500-01-01'), dayOfYear('1500-01-01');
+
+select date '2001-09-28' + 7;
+select 7 + date '2001-09-28';
+select date '2001-10-01' - 7;
+select date '2001-10-01' - date '2001-09-28';

sql/core/src/test/resources/sql-tests/results/datetime.sql.out

@@ -1,5 +1,5 @@
 -- Automatically generated by SQLQueryTestSuite
--- Number of queries: 11
+-- Number of queries: 15
 
 
 -- !query 0
@@ -97,3 +97,35 @@ select year('1500-01-01'), month('1500-01-01'), dayOfYear('1500-01-01')
 struct<year(CAST(1500-01-01 AS DATE)):int,month(CAST(1500-01-01 AS DATE)):int,dayofyear(CAST(1500-01-01 AS DATE)):int>
 -- !query 10 output
 1500	1	1
+
+
+-- !query 11
+select date '2001-09-28' + 7
+-- !query 11 schema
+struct<date_add(DATE '2001-09-28', 7):date>
+-- !query 11 output
+2001-10-05
+
+
+-- !query 12
+select 7 + date '2001-09-28'
+-- !query 12 schema
+struct<date_add(DATE '2001-09-28', 7):date>
+-- !query 12 output
+2001-10-05
+
+
+-- !query 13
+select date '2001-10-01' - 7
+-- !query 13 schema
+struct<date_sub(DATE '2001-10-01', 7):date>
+-- !query 13 output
+2001-09-24
+
+
+-- !query 14
+select date '2001-10-01' - date '2001-09-28'
+-- !query 14 schema
+struct<datediff(DATE '2001-10-01', DATE '2001-09-28'):int>
+-- !query 14 output
+3