From cf7f71bcde345cdb814f01adb8eb7d0f11e8e83f Mon Sep 17 00:00:00 2001
From: Will Noble <wnoble@google.com>
Date: Wed, 7 Jun 2023 18:16:59 -0700
Subject: [PATCH] [CALCITE-5768] JDBC adapter should insert a subquery for a
 query with ORDER BY ordinal

The incorrect query has an ordinal that is not the first item
of the ORDER BY clause:

  SELECT "JOB"
  FROM "scott"."EMP"
  GROUP BY "JOB"
  ORDER BY "JOB", 2

The correct query should have a subquery:

  SELECT "JOB"
  FROM (SELECT "JOB", COUNT("ENAME") AS "$f1"
    FROM "scott"."EMP"
    GROUP BY "JOB"
    ORDER BY "JOB", 2) AS "t0"
---
 .../calcite/rel/rel2sql/SqlImplementor.java    | 12 +++++++-----
 .../rel/rel2sql/RelToSqlConverterTest.java     | 18 ++++++++++++++++++
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/core/src/main/java/org/apache/calcite/rel/rel2sql/SqlImplementor.java b/core/src/main/java/org/apache/calcite/rel/rel2sql/SqlImplementor.java
index f04a5a11cfe4..e90e5dacbc3c 100644
--- a/core/src/main/java/org/apache/calcite/rel/rel2sql/SqlImplementor.java
+++ b/core/src/main/java/org/apache/calcite/rel/rel2sql/SqlImplementor.java
@@ -1898,12 +1898,14 @@ private boolean hasSortByOrdinal(@UnknownInitialization Result this) {
           return false;
         }
         for (SqlNode sqlNode : orderList) {
-          if (!(sqlNode instanceof SqlBasicCall)) {
-            return sqlNode instanceof SqlNumericLiteral;
+          if (sqlNode instanceof SqlNumericLiteral) {
+            return true;
           }
-          for (SqlNode operand : ((SqlBasicCall) sqlNode).getOperandList()) {
-            if (operand instanceof SqlNumericLiteral) {
-              return true;
+          if (sqlNode instanceof SqlBasicCall) {
+            for (SqlNode operand : ((SqlBasicCall) sqlNode).getOperandList()) {
+              if (operand instanceof SqlNumericLiteral) {
+                return true;
+              }
             }
           }
         }
diff --git a/core/src/test/java/org/apache/calcite/rel/rel2sql/RelToSqlConverterTest.java b/core/src/test/java/org/apache/calcite/rel/rel2sql/RelToSqlConverterTest.java
index 412ddb4c165d..9de19094a820 100644
--- a/core/src/test/java/org/apache/calcite/rel/rel2sql/RelToSqlConverterTest.java
+++ b/core/src/test/java/org/apache/calcite/rel/rel2sql/RelToSqlConverterTest.java
@@ -400,6 +400,24 @@ private static String toSql(RelNode root, SqlDialect dialect,
     relFn(relFn).ok(expected);
   }
 
+  @Test void testUsesSubqueryWhenSortingByIdThenOrdinal() {
+    final Function<RelBuilder, RelNode> relFn = b -> b
+        .scan("EMP")
+        .aggregate(
+            b.groupKey("JOB"),
+            b.aggregateCall(SqlStdOperatorTable.COUNT, b.field("ENAME")))
+        .sort(b.field(0), b.field(1))
+        .project(b.field(0))
+        .build();
+    final String expected = "SELECT \"JOB\"\n"
+        + "FROM (SELECT \"JOB\", COUNT(\"ENAME\") AS \"$f1\"\n"
+        + "FROM \"scott\".\"EMP\"\n"
+        + "GROUP BY \"JOB\"\n"
+        + "ORDER BY \"JOB\", 2) AS \"t0\"";
+
+    relFn(relFn).ok(expected);
+  }
+
   @Test void testSelectQueryWithWhereClauseOfBasicOperators() {
     String query = "select * from \"product\" "
         + "where (\"product_id\" = 10 OR \"product_id\" <= 5) "