From ec36f45e8d0fe8b3e2acbb1bc1f90ca1e5ce1d07 Mon Sep 17 00:00:00 2001
From: Lukas Eder <lukas.eder@gmail.com>
Date: Wed, 5 Apr 2023 11:52:24 +0200
Subject: [PATCH] [jOOQ/jOOQ#14908] Missing parentheses when second subquery in
 set operation contains deep nesting

---
 jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java b/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
index 00830a8f8b..3fc0cc7752 100644
--- a/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
@@ -2649,18 +2649,19 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
 
                 for (Select<?> other : union.get(i)) {
                     boolean derivedTableRequired = derivedTableRequired(context, other);
+                    boolean otherUnionParensRequired = unionParensRequired || unionOpNesting();
 
                     context.formatSeparator()
                            .visit(op.toKeyword(family));
 
-                    if (unionParensRequired)
+                    if (otherUnionParensRequired)
                         context.sql(' ');
                     else
                         context.formatSeparator();
 
-                    unionParenthesis(context, '(', other.getSelect(), derivedTableRequired, unionParensRequired);
+                    unionParenthesis(context, '(', other.getSelect(), derivedTableRequired, otherUnionParensRequired);
                     context.visit(other);
-                    unionParenthesis(context, ')', null, derivedTableRequired, unionParensRequired);
+                    unionParenthesis(context, ')', null, derivedTableRequired, otherUnionParensRequired);
                 }
 
                 // [#1658] Close parentheses opened previously
@@ -3400,6 +3401,9 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
     }
 
     private final boolean unionParensRequired(Context<?> context) {
+        if (unionOp.isEmpty())
+            return false;
+
         if (unionParensRequired(this) || context.settings().isRenderParenthesisAroundSetOperationQueries())
             return true;