From 91d933177857eed8a80e5fc82dae82ab03b6c267 Mon Sep 17 00:00:00 2001
From: lukaseder <lukas.eder@gmail.com>
Date: Thu, 3 May 2018 14:02:53 +0200
Subject: [PATCH] [#7459] SEEK with UNION doesn't work correctly

---
 .../java/org/jooq/impl/SelectQueryImpl.java   | 67 +++++++++++++------
 1 file changed, 47 insertions(+), 20 deletions(-)

diff --git a/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java b/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
index 46e1ee3c13..4bc4f1e1c2 100644
--- a/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
@@ -1038,6 +1038,7 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
         // synthetic parentheses
         boolean wrapQueryExpressionInDerivedTable;
         boolean wrapQueryExpressionBodyInDerivedTable = false;
+        boolean applySeekOnDerivedTable = applySeekOnDerivedTable(context);
 
 
         wrapQueryExpressionInDerivedTable = false
@@ -1072,28 +1073,34 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
 
 
 
+        // [#7459] In the presence of UNIONs and other set operations, the SEEK
+        //         predicate must be applied on a derived table, not on the individual subqueries
+        wrapQueryExpressionBodyInDerivedTable |= applySeekOnDerivedTable;
+
+        if (wrapQueryExpressionBodyInDerivedTable) {
+            context.visit(K_SELECT).sql(' ');
 
 
 
 
 
+            context.formatIndentStart()
+                   .formatNewLine()
+                   .sql("t.*");
 
+            if (alternativeFields != null && originalFields.length < alternativeFields.length)
+                context.sql(", ")
+                       .formatSeparator()
+                       .declareFields(true)
+                       .visit(alternativeFields[alternativeFields.length - 1])
+                       .declareFields(false);
 
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
+            context.formatIndentEnd()
+                   .formatSeparator()
+                   .visit(K_FROM).sql(" (")
+                   .formatIndentStart()
+                   .formatNewLine();
+        }
 
         // [#1658] jOOQ applies left-associativity to set operators. In order to enforce that across
         // all databases, we need to wrap relevant subqueries in parentheses.
@@ -1424,12 +1431,22 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
                 context.data().remove(DATA_NESTED_SET_OPERATIONS);
         }
 
+        if (wrapQueryExpressionBodyInDerivedTable) {
+            context.formatIndentEnd()
+                   .formatNewLine()
+                   .sql(") t");
 
+            if (applySeekOnDerivedTable) {
+                boolean qualify = context.qualify();
 
-
-
-
-
+                context.formatSeparator()
+                       .visit(K_WHERE)
+                       .sql(' ')
+                       .qualify(false)
+                       .visit(getSeekCondition())
+                       .qualify(qualify);
+            }
+        }
 
         // ORDER BY clause for UNION
         // -------------------------
@@ -1527,6 +1544,10 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
             ctx.visit(actualLimit);
     }
 
+    private final boolean applySeekOnDerivedTable(Context<?> ctx) {
+        return !getSeek().isEmpty() && !getOrderBy().isEmpty() && !unionOp.isEmpty();
+    }
+
     private final boolean wrapQueryExpressionBodyInDerivedTable(Context<?> ctx) {
         return true
 
@@ -1924,7 +1945,13 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
     }
 
     final ConditionProviderImpl getWhere() {
-        if (getOrderBy().isEmpty() || getSeek().isEmpty())
+
+        // Do not apply SEEK predicates in the WHERE clause, if:
+        // - There is no ORDER BY clause (SEEK is non-deterministic)
+        // - There is no SEEK clause (obvious case)
+        // - There are unions (union is nested in derived table
+        //   and SEEK predicate is applied outside). See [#7459]
+        if (getOrderBy().isEmpty() || getSeek().isEmpty() || unionOp.size() > 0)
             return condition;
 
         ConditionProviderImpl result = new ConditionProviderImpl();