From 2e7be261c64bc4520e20725ad90e92602da0ce9a Mon Sep 17 00:00:00 2001
From: Lukas Eder <lukas.eder@datageekery.com>
Date: Thu, 17 Oct 2024 11:49:49 +0200
Subject: [PATCH] [jOOQ/jOOQ#7539] Auto-alias CTE contents

---
 .../jooq/impl/CommonTableExpressionImpl.java   | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/jOOQ/src/main/java/org/jooq/impl/CommonTableExpressionImpl.java b/jOOQ/src/main/java/org/jooq/impl/CommonTableExpressionImpl.java
index 5bac360ef4..4195006a4d 100644
--- a/jOOQ/src/main/java/org/jooq/impl/CommonTableExpressionImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/CommonTableExpressionImpl.java
@@ -51,6 +51,8 @@ import static org.jooq.impl.Keywords.K_AS;
 import static org.jooq.impl.Keywords.K_MATERIALIZED;
 import static org.jooq.impl.Keywords.K_NOT;
 import static org.jooq.impl.SubqueryCharacteristics.DERIVED_TABLE;
+import static org.jooq.impl.Tools.isEmpty;
+import static org.jooq.impl.Tools.isNotEmpty;
 import static org.jooq.impl.Tools.map;
 import static org.jooq.impl.Tools.visitSubquery;
 
@@ -61,6 +63,7 @@ import org.jooq.Context;
 import org.jooq.DataType;
 import org.jooq.DerivedColumnList;
 import org.jooq.Field;
+import org.jooq.Name;
 // ...
 import org.jooq.QueryPart;
 import org.jooq.Record;
@@ -79,8 +82,9 @@ import org.jooq.impl.Tools.SimpleDataKey;
  */
 final class CommonTableExpressionImpl<R extends Record> extends AbstractTable<R> implements CommonTableExpression<R> {
 
-    static final Set<SQLDialect> SUPPORT_MATERIALIZED   = SQLDialect.supportedBy(POSTGRES, SQLITE);
-    static final Set<SQLDialect> NO_SUPPORT_COLUMN_LIST = SQLDialect.supportedBy(CLICKHOUSE);
+    static final Set<SQLDialect> SUPPORT_MATERIALIZED      = SQLDialect.supportedBy(POSTGRES, SQLITE);
+    static final Set<SQLDialect> NO_SUPPORT_COLUMN_LIST    = SQLDialect.supportedBy(CLICKHOUSE);
+    static final Set<SQLDialect> REQUIRE_EXPLICIT_ALIASING = SQLDialect.supportedBy(CLICKHOUSE);
 
 
 
@@ -133,7 +137,7 @@ final class CommonTableExpressionImpl<R extends Record> extends AbstractTable<R>
             QueryPart s = query;
 
             // [#4474] [#16629] Support this for ResultQuery as well
-            if (NO_SUPPORT_COLUMN_LIST.contains(ctx.dialect())) {
+            if (NO_SUPPORT_COLUMN_LIST.contains(ctx.dialect()) && isNotEmpty(name.fieldNames)) {
                 ctx.visit(name.name);
 
                 if (query instanceof Select<R> q)
@@ -144,6 +148,14 @@ final class CommonTableExpressionImpl<R extends Record> extends AbstractTable<R>
                             query
                         );
             }
+
+            // [#7539] The automatic aliases generated by ClickHouse for CTE and derived tables are unreliable
+            else if (REQUIRE_EXPLICIT_ALIASING.contains(ctx.dialect()) && isEmpty(name.fieldNames)) {
+                ctx.visit(name.name);
+
+                if (query instanceof Select<R> q)
+                    s = new AliasedSelect<>(q, false, true, false, map(q.getSelect(), f -> f.getUnqualifiedName(), Name[]::new));
+            }
             else
                 ctx.visit(name);