From 8fd072bd72cc66d66c0ef14136646bd8b7c41c70 Mon Sep 17 00:00:00 2001
From: Lukas Eder <lukas.eder@datageekery.com>
Date: Fri, 1 Mar 2024 10:04:20 +0100
Subject: [PATCH] [jOOQ/jOOQ#16392] Regression in fetchCount execution when
 argument query uses plain SQL tables

This includes:

- [jOOQ/jOOQ#16393] Empty derived column lists generate wrong SQL syntax
---
 jOOQ/src/main/java/org/jooq/impl/Alias.java           | 11 ++++++++---
 .../main/java/org/jooq/impl/InlineDerivedTable.java   |  2 +-
 jOOQ/src/main/java/org/jooq/impl/TableAlias.java      |  6 +-----
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/jOOQ/src/main/java/org/jooq/impl/Alias.java b/jOOQ/src/main/java/org/jooq/impl/Alias.java
index 0c6c872963..80d5c1c3a6 100644
--- a/jOOQ/src/main/java/org/jooq/impl/Alias.java
+++ b/jOOQ/src/main/java/org/jooq/impl/Alias.java
@@ -88,6 +88,7 @@ import static org.jooq.impl.QueryPartListView.wrap;
 import static org.jooq.impl.SubqueryCharacteristics.DERIVED_TABLE;
 import static org.jooq.impl.Tools.EMPTY_NAME;
 import static org.jooq.impl.Tools.combine;
+import static org.jooq.impl.Tools.isNotEmpty;
 import static org.jooq.impl.Tools.map;
 import static org.jooq.impl.Tools.visitSubquery;
 import static org.jooq.impl.Tools.BooleanDataKey.DATA_AS_REQUIRED;
@@ -157,6 +158,10 @@ final class Alias<Q extends QueryPart> extends AbstractQueryPart implements UEmp
         return wrapped;
     }
 
+    final boolean hasFieldAliases() {
+        return isNotEmpty(fieldAliases);
+    }
+
     @Override
     public final boolean isSimple(Context<?> ctx) {
         return wrapped instanceof Table && !ctx.declareTables()
@@ -233,7 +238,7 @@ final class Alias<Q extends QueryPart> extends AbstractQueryPart implements UEmp
         // [#454] [#1801] Some databases don't allow "derived column names" in
         // "simple class specifications", or "common table expression references".
         // Hence, wrap the table reference in a subselect
-        if (fieldAliases != null
+        if (hasFieldAliases()
                 && (SUPPORT_DERIVED_COLUMN_NAMES_SPECIAL1.contains(dialect))
                 && (wrapped instanceof TableImpl || wrapped instanceof CommonTableExpressionImpl)) {
 
@@ -243,7 +248,7 @@ final class Alias<Q extends QueryPart> extends AbstractQueryPart implements UEmp
         // [#1801] Some databases do not support "derived column names".
         // They can be emulated by concatenating a dummy SELECT with no
         // results using UNION ALL
-        else if (fieldAliases != null && (
+        else if (hasFieldAliases() && (
                 emulatedDerivedColumnList
              || SUPPORT_DERIVED_COLUMN_NAMES_SPECIAL2.contains(dialect)
 
@@ -341,7 +346,7 @@ final class Alias<Q extends QueryPart> extends AbstractQueryPart implements UEmp
                .qualify(false, c -> c.visit(alias));
 
         // [#1801] Add field aliases to the table alias, if applicable
-        if (fieldAliases != null && !emulatedDerivedColumnList) {
+        if (hasFieldAliases() && !emulatedDerivedColumnList) {
             toSQLDerivedColumnList(context);
         }
 
diff --git a/jOOQ/src/main/java/org/jooq/impl/InlineDerivedTable.java b/jOOQ/src/main/java/org/jooq/impl/InlineDerivedTable.java
index f3c7e5a4a8..27999e5d0f 100644
--- a/jOOQ/src/main/java/org/jooq/impl/InlineDerivedTable.java
+++ b/jOOQ/src/main/java/org/jooq/impl/InlineDerivedTable.java
@@ -231,7 +231,7 @@ final class InlineDerivedTable<R extends Record> extends DerivedTable<R> {
                 if (u.where != null) {
                     Select<R> q = new InlineDerivedTable<>(u).query();
 
-                    if (a.hasFieldAliases())
+                    if (a.alias.hasFieldAliases())
                         return q.asTable(a.getUnqualifiedName(), a.alias.fieldAliases);
                     else
                         return q.asTable(a);
diff --git a/jOOQ/src/main/java/org/jooq/impl/TableAlias.java b/jOOQ/src/main/java/org/jooq/impl/TableAlias.java
index 77546d274a..3e82bcba7d 100644
--- a/jOOQ/src/main/java/org/jooq/impl/TableAlias.java
+++ b/jOOQ/src/main/java/org/jooq/impl/TableAlias.java
@@ -104,7 +104,7 @@ implements
 
         // [#13418]
         List<Field<?>> result = Tools.map(this.alias.wrapped().fieldsRow().fields(), (f, i) -> new TableFieldImpl(
-              hasFieldAliases() && alias.fieldAliases.length > i
+              alias.hasFieldAliases() && alias.fieldAliases.length > i
             ? alias.fieldAliases[i]
             : f.getUnqualifiedName(), removeGenerator(CONFIG.get(), f.getDataType()), this, f.getCommentPart(), f.getBinding()
         ));
@@ -112,10 +112,6 @@ implements
         return new FieldsImpl<>(result);
     }
 
-    final boolean hasFieldAliases() {
-        return alias.fieldAliases != null;
-    }
-
     /**
      * Get the aliased table wrapped by this table.
      */