From 1b995d1e26cb3655ed2296383a5b68062aa9dc14 Mon Sep 17 00:00:00 2001
From: Robin Sue <robinsue@live.de>
Date: Tue, 18 Oct 2022 20:16:16 +0200
Subject: [PATCH] UseAlias

---
 .../SqlExpressions/SelectExpression.Helper.cs | 23 +++++++++++++++++++
 .../Query/SqlExpressions/SelectExpression.cs  |  6 +++++
 2 files changed, 29 insertions(+)

diff --git a/src/EFCore.Relational/Query/SqlExpressions/SelectExpression.Helper.cs b/src/EFCore.Relational/Query/SqlExpressions/SelectExpression.Helper.cs
index b1681821729..25edf3bd1f9 100644
--- a/src/EFCore.Relational/Query/SqlExpressions/SelectExpression.Helper.cs
+++ b/src/EFCore.Relational/Query/SqlExpressions/SelectExpression.Helper.cs
@@ -154,6 +154,29 @@ public ProjectionIndexRemappingExpressionVisitor(
         }
     }
 
+    private sealed class UseAliasExpressionVisitor : ExpressionVisitor
+    {
+        private readonly SelectExpression _queryExpression;
+
+        public UseAliasExpressionVisitor(SelectExpression queryExpression)
+        {
+            _queryExpression = queryExpression;
+        }
+
+        [return: NotNullIfNotNull("expression")]
+        public override Expression? Visit(Expression? expression)
+        {
+            foreach (var x in _queryExpression.Projection)
+            {
+                if (x.Expression.Equals(expression))
+                {
+                    return new SqlFragmentExpression(x.Alias);
+                }
+            }
+            return base.Visit(expression);
+        }
+    }
+
     private sealed class SqlRemappingVisitor : ExpressionVisitor
     {
         private readonly SelectExpression _subquery;
diff --git a/src/EFCore.Relational/Query/SqlExpressions/SelectExpression.cs b/src/EFCore.Relational/Query/SqlExpressions/SelectExpression.cs
index e6c7ddf1997..65e0931c8c7 100644
--- a/src/EFCore.Relational/Query/SqlExpressions/SelectExpression.cs
+++ b/src/EFCore.Relational/Query/SqlExpressions/SelectExpression.cs
@@ -1570,6 +1570,12 @@ Expression CopyProjectionToOuter(SelectExpression innerSelectExpression, Express
             _projectionMapping.Clear();
             _projectionMapping = result;
 
+            var useAliasVisitor = new UseAliasExpressionVisitor(this);
+            for (var i = 0; i < _orderings.Count; i++)
+            {
+                _orderings[i] = useAliasVisitor.VisitAndConvert(_orderings[i], nameof(ApplyProjection));
+            }
+
             return shaperExpression;
         }