Query: Convert unflattened GroupJoin to correlated subquery

Resolves #19930
dotnet · Sep 6, 2022 · f2caabf · f2caabf
1 parent c11d084
commit f2caabf
Show file tree

Hide file tree

Showing 4 changed files with 169 additions and 0 deletions.
diff --git a/src/EFCore/Query/Internal/QueryableMethodNormalizingExpressionVisitor.cs b/src/EFCore/Query/Internal/QueryableMethodNormalizingExpressionVisitor.cs
@@ -584,6 +584,48 @@ private Expression TryFlattenGroupJoinSelectMany(MethodCallExpression methodCall
                 }
             }
         }
+        else if (genericMethod == QueryableMethods.GroupJoin)
+        {
+            var genericArguments = methodCallExpression.Method.GetGenericArguments();
+            var outerSource = methodCallExpression.Arguments[0];
+            var innerSource = methodCallExpression.Arguments[1];
+            var outerKeySelector = methodCallExpression.Arguments[2].UnwrapLambdaFromQuote();
+            var innerKeySelector = methodCallExpression.Arguments[3].UnwrapLambdaFromQuote();
+            var resultSelector = methodCallExpression.Arguments[4].UnwrapLambdaFromQuote();
+
+            var correlationPredicate = ReplacingExpressionVisitor.Replace(
+                outerKeySelector.Parameters[0],
+                resultSelector.Parameters[0],
+                Expression.AndAlso(
+                    Infrastructure.ExpressionExtensions.CreateEqualsExpression(
+                        outerKeySelector.Body,
+                        Expression.Constant(null),
+                        negated: true),
+                    Infrastructure.ExpressionExtensions.CreateEqualsExpression(
+                        outerKeySelector.Body,
+                        innerKeySelector.Body)));
+
+            innerSource = Expression.Call(
+                QueryableMethods.Where.MakeGenericMethod(genericArguments[1]),
+                innerSource,
+                Expression.Quote(
+                    Expression.Lambda(
+                        correlationPredicate,
+                        innerKeySelector.Parameters)));
+
+            var selector = ReplacingExpressionVisitor.Replace(
+                resultSelector.Parameters[1],
+                innerSource,
+                resultSelector.Body);
+
+            return Expression.Call(
+                QueryableMethods.Select.MakeGenericMethod(genericArguments[0], genericArguments[3]),
+                outerSource,
+                Expression.Quote(
+                    Expression.Lambda(
+                        selector,
+                        resultSelector.Parameters[0])));
+        }
 
         return methodCallExpression;
     }

diff --git a/test/EFCore.Specification.Tests/Query/NorthwindJoinQueryTestBase.cs b/test/EFCore.Specification.Tests/Query/NorthwindJoinQueryTestBase.cs
@@ -446,6 +446,62 @@ from o2 in orders
                 },
             e => (e.A, e.B, e.C));
 
+    [ConditionalTheory]
+    [MemberData(nameof(IsAsyncData))]
+    public virtual Task GroupJoin_as_final_operator(bool async)
+        => AssertQuery(
+            async,
+            ss =>
+                from c in ss.Set<Customer>().Where(c => c.CustomerID.StartsWith("F"))
+                join o in ss.Set<Order>() on c.CustomerID equals o.CustomerID into orders
+                select new { c, orders },
+            e => e.c.CustomerID,
+            elementAsserter: (e, a) =>
+            {
+                AssertEqual(e.c, a.c);
+                AssertCollection(e.orders, a.orders);
+            },
+            entryCount: 71);
+
+    [ConditionalTheory]
+    [MemberData(nameof(IsAsyncData))]
+    public virtual Task Unflattened_GroupJoin_composed(bool async)
+        => AssertQuery(
+            async,
+            ss =>
+            from i in (from c in ss.Set<Customer>().Where(c => c.CustomerID.StartsWith("F"))
+                       join o in ss.Set<Order>() on c.CustomerID equals o.CustomerID into orders
+                       select new { c, orders })
+            where i.c.City == "Lisboa"
+            select i,
+            e => e.c.CustomerID,
+            elementAsserter: (e, a) =>
+            {
+                AssertEqual(e.c, a.c);
+                AssertCollection(e.orders, a.orders);
+            },
+            entryCount: 9);
+
+    [ConditionalTheory]
+    [MemberData(nameof(IsAsyncData))]
+    public virtual Task Unflattened_GroupJoin_composed_2(bool async)
+        => AssertQuery(
+            async,
+            ss =>
+            from i in (from c in ss.Set<Customer>().Where(c => c.CustomerID.StartsWith("F"))
+                       join o in ss.Set<Order>() on c.CustomerID equals o.CustomerID into orders
+                       select new { c, orders })
+            join c2 in ss.Set<Customer>().Where(n => n.City == "Lisboa") on i.c.CustomerID equals c2.CustomerID
+            select new { i, c2 },
+            e => e.i.c.CustomerID,
+            elementAsserter: (e, a) =>
+            {
+                AssertEqual(e.c2, a.c2);
+                AssertEqual(e.i.c, a.i.c);
+                AssertCollection(e.i.orders, a.i.orders);
+            },
+            entryCount: 9);
+
     [ConditionalTheory]
     [MemberData(nameof(IsAsyncData))]
     public virtual Task GroupJoin_DefaultIfEmpty(bool async)

diff --git a/test/EFCore.SqlServer.FunctionalTests/Query/NorthwindJoinQuerySqlServerTest.cs b/test/EFCore.SqlServer.FunctionalTests/Query/NorthwindJoinQuerySqlServerTest.cs
@@ -267,6 +267,59 @@ ORDER BY [o].[OrderID]
 ) AS [t] ON [c].[CustomerID] = [t].[CustomerID]");
     }
 
+    public override async Task GroupJoin_as_final_operator(bool async)
+    {
+        await base.GroupJoin_as_final_operator(async);
+
+        AssertSql(
+            @"SELECT [c].[CustomerID], [c].[Address], [c].[City], [c].[CompanyName], [c].[ContactName], [c].[ContactTitle], [c].[Country], [c].[Fax], [c].[Phone], [c].[PostalCode], [c].[Region], [t].[OrderID], [t].[CustomerID], [t].[EmployeeID], [t].[OrderDate]
+FROM [Customers] AS [c]
+OUTER APPLY (
+    SELECT [o].[OrderID], [o].[CustomerID], [o].[EmployeeID], [o].[OrderDate]
+    FROM [Orders] AS [o]
+    WHERE [c].[CustomerID] = [o].[CustomerID]
+) AS [t]
+WHERE [c].[CustomerID] LIKE N'F%'
+ORDER BY [c].[CustomerID]");
+    }
+
+    public override async Task Unflattened_GroupJoin_composed(bool async)
+    {
+        await base.Unflattened_GroupJoin_composed(async);
+
+        AssertSql(
+            @"SELECT [c].[CustomerID], [c].[Address], [c].[City], [c].[CompanyName], [c].[ContactName], [c].[ContactTitle], [c].[Country], [c].[Fax], [c].[Phone], [c].[PostalCode], [c].[Region], [t].[OrderID], [t].[CustomerID], [t].[EmployeeID], [t].[OrderDate]
+FROM [Customers] AS [c]
+OUTER APPLY (
+    SELECT [o].[OrderID], [o].[CustomerID], [o].[EmployeeID], [o].[OrderDate]
+    FROM [Orders] AS [o]
+    WHERE [c].[CustomerID] = [o].[CustomerID]
+) AS [t]
+WHERE ([c].[CustomerID] LIKE N'F%') AND [c].[City] = N'Lisboa'
+ORDER BY [c].[CustomerID]");
+    }
+
+    public override async Task Unflattened_GroupJoin_composed_2(bool async)
+    {
+        await base.Unflattened_GroupJoin_composed_2(async);
+
+        AssertSql(
+            @"SELECT [c].[CustomerID], [c].[Address], [c].[City], [c].[CompanyName], [c].[ContactName], [c].[ContactTitle], [c].[Country], [c].[Fax], [c].[Phone], [c].[PostalCode], [c].[Region], [t].[CustomerID], [t0].[OrderID], [t0].[CustomerID], [t0].[EmployeeID], [t0].[OrderDate], [t].[Address], [t].[City], [t].[CompanyName], [t].[ContactName], [t].[ContactTitle], [t].[Country], [t].[Fax], [t].[Phone], [t].[PostalCode], [t].[Region]
+FROM [Customers] AS [c]
+INNER JOIN (
+    SELECT [c0].[CustomerID], [c0].[Address], [c0].[City], [c0].[CompanyName], [c0].[ContactName], [c0].[ContactTitle], [c0].[Country], [c0].[Fax], [c0].[Phone], [c0].[PostalCode], [c0].[Region]
+    FROM [Customers] AS [c0]
+    WHERE [c0].[City] = N'Lisboa'
+) AS [t] ON [c].[CustomerID] = [t].[CustomerID]
+OUTER APPLY (
+    SELECT [o].[OrderID], [o].[CustomerID], [o].[EmployeeID], [o].[OrderDate]
+    FROM [Orders] AS [o]
+    WHERE [c].[CustomerID] = [o].[CustomerID]
+) AS [t0]
+WHERE [c].[CustomerID] LIKE N'F%'
+ORDER BY [c].[CustomerID], [t].[CustomerID]");
+    }
+
     public override async Task GroupJoin_DefaultIfEmpty(bool async)
     {
         await base.GroupJoin_DefaultIfEmpty(async);

diff --git a/test/EFCore.Sqlite.FunctionalTests/Query/NorthwindJoinQuerySqliteTest.cs b/test/EFCore.Sqlite.FunctionalTests/Query/NorthwindJoinQuerySqliteTest.cs
@@ -55,4 +55,22 @@ public override async Task Take_in_collection_projection_with_FirstOrDefault_on_
             SqliteStrings.ApplyNotSupported,
             (await Assert.ThrowsAsync<InvalidOperationException>(
                 () => base.Take_in_collection_projection_with_FirstOrDefault_on_top_level(async))).Message);
+
+    public override async Task GroupJoin_as_final_operator(bool async)
+        => Assert.Equal(
+            SqliteStrings.ApplyNotSupported,
+            (await Assert.ThrowsAsync<InvalidOperationException>(
+                () => base.GroupJoin_as_final_operator(async))).Message);
+
+    public override async Task Unflattened_GroupJoin_composed(bool async)
+        => Assert.Equal(
+            SqliteStrings.ApplyNotSupported,
+            (await Assert.ThrowsAsync<InvalidOperationException>(
+                () => base.Unflattened_GroupJoin_composed(async))).Message);
+
+    public override async Task Unflattened_GroupJoin_composed_2(bool async)
+        => Assert.Equal(
+            SqliteStrings.ApplyNotSupported,
+            (await Assert.ThrowsAsync<InvalidOperationException>(
+                () => base.Unflattened_GroupJoin_composed_2(async))).Message);
 }