SQL: Fix ORDER BY YEAR() function

x-pack/plugin/ql/src/main/java/org/elasticsearch/xpack/ql/expression/function/scalar/ScalarFunction.java

@@ -39,17 +39,15 @@ protected ScalarFunction(Source source, List<Expression> fields) {
         super(source, fields);
     }
 
-    // used if the function is monotonic and thus does not have to be computed for ordering purposes
-    // null means the script needs to be used; expression means the field/expression to be used instead
+    // Every function needs to be translated to a script
+    // which will be used for the ordering
     public Expression orderBy() {
         return null;
     }
 
-
     //
     // Script generation
     //
-
     public ScriptTemplate asScript(Expression exp) {
         if (exp.foldable()) {
             return scriptWithFoldable(exp);
@@ -73,7 +71,6 @@ public ScriptTemplate asScript(Expression exp) {
         throw new QlIllegalArgumentException("Cannot evaluate script for expression {}", exp);
     }
 
-
     protected ScriptTemplate scriptWithFoldable(Expression foldable) {
         Object fold = foldable.fold();
 
@@ -144,4 +141,4 @@ protected String processScript(String script) {
     protected String formatTemplate(String template) {
         return Scripts.formatTemplate(template);
     }
-}
+}

x-pack/plugin/sql/qa/src/main/resources/datetime.sql-spec

@@ -124,6 +124,12 @@ SELECT first_name FROM test_emp ORDER BY NOW(), first_name NULLS LAST LIMIT 5;
 groupByCurrentTimestamp
 SELECT MAX(salary) AS max FROM test_emp GROUP BY NOW();
 
+//
+// ORDER BY
+//
+orderByYear
+SELECT YEAR(birth_date) as year, emp_no FROM test_emp ORDER BY year NULLS FIRST, emp_no ASC;
+
 // ES will consider a TIME in UTC, if no other indication is given and H2 doesn't consider the timezone for times, so no TZSync'ing needed.
 hourFromStringTime
 SELECT HOUR(CAST('18:09:03' AS TIME)) AS result;

x-pack/plugin/sql/qa/src/main/resources/docs/docs.csv-spec

@@ -939,7 +939,7 @@ SELECT -2 * INTERVAL '3' YEARS AS result;
 
 ///////////////////////////////
 //
-// Order by
+// Order By
 //
 ///////////////////////////////
 

x-pack/plugin/sql/qa/src/main/resources/nested.csv-spec

@@ -106,23 +106,23 @@ SELECT first_name f, last_name l, YEAR(dep.from_date) start FROM test_emp WHERE
 
 f:s                  | l:s           | start:i
 
-Sreekrishna          |Servieres      |1985           
-Zhongwei             |Rosen          |1986           
-Chirstian            |Koblick        |1986           
-null                 |Chappelet      |1988           
-Zvonko               |Nyanchama      |1989     
+Parto                |Bamford        |1995
+Chirstian            |Koblick        |1986
+Duangkaew            |Piveteau       |1996
+Kazuhide             |Peha           |1992
+null                 |Demeyer        |1994
 ;
 
 selectWithScalarOnNestedWithoutProjection
 SELECT first_name f, last_name l FROM test_emp WHERE dep.dep_name = 'Production' AND languages > 1 ORDER BY YEAR(dep.from_date) LIMIT 5;
 
 f:s                  | l:s
 
-Sreekrishna          |Servieres      
-Zhongwei             |Rosen          
-Chirstian            |Koblick        
-null                 |Chappelet      
-Zvonko               |Nyanchama  
+Parto                |Bamford
+Chirstian            |Koblick
+Duangkaew            |Piveteau
+Kazuhide             |Peha
+null                 |Demeyer
 ;
 
 //

x-pack/plugin/sql/src/main/java/org/elasticsearch/xpack/sql/expression/function/scalar/datetime/Year.java

@@ -39,11 +39,6 @@ public String dateTimeFormat() {
         return "year";
     }
 
-    @Override
-    public Expression orderBy() {
-        return field();
-    }
-
     @Override
     public String calendarInterval() {
         return YEAR_INTERVAL;