From 16df2e309d7f99d0797d8ab61bb9ff08afe0a4ae Mon Sep 17 00:00:00 2001
From: lukaseder <lukas.eder@gmail.com>
Date: Thu, 14 Mar 2019 10:14:37 +0100
Subject: [PATCH] [#8414] Don't emulate empty ORDER BY clause in H2's
 ROW_NUMBER() function

---
 .../src/main/java/org/jooq/impl/Function.java | 23 +++++++++++++++----
 jOOQ/src/main/java/org/jooq/impl/Tools.java   |  5 ++++
 .../jooq/impl/WindowSpecificationImpl.java    | 12 ++++++++++
 3 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/jOOQ/src/main/java/org/jooq/impl/Function.java b/jOOQ/src/main/java/org/jooq/impl/Function.java
index 535f38a9b4..441466b5cb 100644
--- a/jOOQ/src/main/java/org/jooq/impl/Function.java
+++ b/jOOQ/src/main/java/org/jooq/impl/Function.java
@@ -89,6 +89,7 @@ import static org.jooq.impl.Term.MODE;
 import static org.jooq.impl.Term.PRODUCT;
 import static org.jooq.impl.Term.ROW_NUMBER;
 import static org.jooq.impl.Tools.BooleanDataKey.DATA_RANKING_FUNCTION;
+import static org.jooq.impl.Tools.BooleanDataKey.DATA_ROWNUMBER_FUNCTION;
 import static org.jooq.impl.Tools.DataKey.DATA_WINDOW_DEFINITIONS;
 
 import java.math.BigDecimal;
@@ -424,10 +425,17 @@ class Function<T> extends AbstractField<T> implements
             return;
 
         Boolean ranking = false;
-        Boolean previous = null;
+        Boolean rowNumber = false;
+        Boolean previousRanking = null;
+        Boolean previousRowNumber = null;
 
         if (term != null) {
             switch (term) {
+                case ROW_NUMBER:
+                    rowNumber = true;
+                    ranking = true;
+                    break;
+
                 case CUME_DIST:
                 case DENSE_RANK:
                 case FIRST_VALUE:
@@ -438,7 +446,6 @@ class Function<T> extends AbstractField<T> implements
                 case NTILE:
                 case PERCENT_RANK:
                 case RANK:
-                case ROW_NUMBER:
                     ranking = true;
                     break;
             }
@@ -448,14 +455,20 @@ class Function<T> extends AbstractField<T> implements
            .visit(K_OVER)
            .sql(' ');
 
-        previous = (Boolean) ctx.data(DATA_RANKING_FUNCTION, ranking);
+        previousRanking = (Boolean) ctx.data(DATA_RANKING_FUNCTION, ranking);
+        previousRowNumber = (Boolean) ctx.data(DATA_ROWNUMBER_FUNCTION, rowNumber);
 
         ctx.visit(window);
 
-        if (TRUE.equals(previous))
-            ctx.data(DATA_RANKING_FUNCTION, previous);
+        if (TRUE.equals(previousRanking))
+            ctx.data(DATA_RANKING_FUNCTION, previousRanking);
         else
             ctx.data().remove(DATA_RANKING_FUNCTION);
+
+        if (TRUE.equals(previousRowNumber))
+            ctx.data(DATA_ROWNUMBER_FUNCTION, previousRowNumber);
+        else
+            ctx.data().remove(DATA_ROWNUMBER_FUNCTION);
     }
 
     @SuppressWarnings("unchecked")
diff --git a/jOOQ/src/main/java/org/jooq/impl/Tools.java b/jOOQ/src/main/java/org/jooq/impl/Tools.java
index a36979c68d..a7c4222434 100644
--- a/jOOQ/src/main/java/org/jooq/impl/Tools.java
+++ b/jOOQ/src/main/java/org/jooq/impl/Tools.java
@@ -452,6 +452,11 @@ final class Tools {
          */
         DATA_EMULATE_BULK_INSERT_RETURNING,
 
+        /**
+         * [#8414] We're currently generating the window specification of a row_number function.
+         */
+        DATA_ROWNUMBER_FUNCTION,
+
         /**
          * [#1535] We're currently generating the window specification of a ranking function.
          */
diff --git a/jOOQ/src/main/java/org/jooq/impl/WindowSpecificationImpl.java b/jOOQ/src/main/java/org/jooq/impl/WindowSpecificationImpl.java
index 90800108cb..ea746f9c07 100644
--- a/jOOQ/src/main/java/org/jooq/impl/WindowSpecificationImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/WindowSpecificationImpl.java
@@ -62,6 +62,7 @@ import static org.jooq.impl.Keywords.K_PRECEDING;
 import static org.jooq.impl.Keywords.K_UNBOUNDED_FOLLOWING;
 import static org.jooq.impl.Keywords.K_UNBOUNDED_PRECEDING;
 import static org.jooq.impl.Tools.BooleanDataKey.DATA_RANKING_FUNCTION;
+import static org.jooq.impl.Tools.BooleanDataKey.DATA_ROWNUMBER_FUNCTION;
 import static org.jooq.impl.WindowSpecificationImpl.Exclude.CURRENT_ROW;
 import static org.jooq.impl.WindowSpecificationImpl.Exclude.GROUP;
 import static org.jooq.impl.WindowSpecificationImpl.Exclude.NO_OTHERS;
@@ -162,6 +163,17 @@ final class WindowSpecificationImpl extends AbstractQueryPart implements
 
             glue = " ";
         }
+        else if (TRUE.equals(ctx.data(DATA_ROWNUMBER_FUNCTION)) && REQUIRES_ORDER_BY_IN_RANKING.contains(ctx.family())) {
+
+            // [#8414] H2 requires ORDER BY in all other ranking functions than ROW_NUMBER()
+            if (ctx.family() != H2) {
+                ctx.sql(glue)
+                   .visit(K_ORDER_BY).sql(' ')
+                   .visit(field(select(one())));
+
+                glue = " ";
+            }
+        }
         else if (TRUE.equals(ctx.data(DATA_RANKING_FUNCTION)) && REQUIRES_ORDER_BY_IN_RANKING.contains(ctx.family())) {
             ctx.sql(glue)
                .visit(K_ORDER_BY).sql(' ')