Query: ProjectionShaper ignores the offset while Shaping

[smitpatel]

Query:

from c1_Orders in context.Orders
join _c1 in
   (from c1 in
	(from c in context.Customers
		orderby c.CustomerID
		select c)
	.Take(2)
	from c2 in context.Customers
	select new { CustomerID = EF.Property<string>(c1, "CustomerID") })
   .Distinct()
on EF.Property<string>(c1_Orders, "CustomerID") equals _c1.CustomerID
orderby _c1.CustomerID
select c1_Orders

Generates following query

exec sp_executesql N'SELECT [c1_Orders].[OrderID], [c1_Orders].[CustomerID], [c1_Orders].[EmployeeID], [c1_Orders].[OrderDate], [t0].[CustomerID]
FROM [Orders] AS [c1_Orders]
INNER JOIN (
    SELECT DISTINCT [t].[CustomerID]
    FROM (
        SELECT TOP(@__p_0) [c].*
        FROM [Customers] AS [c]
        ORDER BY [c].[CustomerID]
    ) AS [t]
    CROSS JOIN [Customers] AS [c2]
) AS [t0] ON [c1_Orders].[CustomerID] = [t0].[CustomerID]',N'@__p_0 int',@__p_0=2

Which is correct. Though it throws following exception.

Test 'Microsoft.EntityFrameworkCore.SqlServer.FunctionalTests.QuerySqlServerTest.Lifting_when_subquery_nested_order_by_anonymous' failed:
	System.InvalidCastException : Unable to cast object of type 'System.Int32' to type 'System.String'.
	at lambda_method(Closure , QueryContext , TransparentIdentifier`2 )
	D:\EntityFramework\src\EFCore.Relational\Query\ExpressionVisitors\Internal\ProjectionShaper.cs(97,0): at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.Internal.ProjectionShaper.TypedProjectionShaper`3.Shape(QueryContext queryContext, ValueBuffer valueBuffer)
	D:\EntityFramework\src\EFCore.Relational\Query\ExpressionVisitors\Internal\CompositeShaper.cs(98,0): at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.Internal.CompositeShaper.TypedCompositeShaper`5.Shape(QueryContext queryContext, ValueBuffer valueBuffer)
	D:\EntityFramework\src\EFCore.Relational\Query\QueryMethodProvider.cs(48,0): at Microsoft.EntityFrameworkCore.Query.QueryMethodProvider.<_ShapedQuery>d__3`1.MoveNext()
	at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
	at System.Linq.OrderedEnumerable`1.<GetEnumerator>d__1.MoveNext()
	at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
	D:\EntityFramework\src\EFCore\Query\Internal\LinqOperatorProvider.cs(178,0): at Microsoft.EntityFrameworkCore.Query.Internal.LinqOperatorProvider.<_TrackEntities>d__17`2.MoveNext()
	D:\EntityFramework\src\EFCore\Query\Internal\LinqOperatorProvider.cs(147,0): at Microsoft.EntityFrameworkCore.Query.Internal.LinqOperatorProvider.ExceptionInterceptor`1.EnumeratorExceptionInterceptor.MoveNext()
	at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
	at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
	D:\EntityFramework\src\EFCore.Specification.Tests\QueryTestBase.cs(60,0): at Microsoft.EntityFrameworkCore.Specification.Tests.QueryTestBase`1.Lifting_when_subquery_nested_order_by_anonymous()
	D:\EntityFramework\test\EFCore.SqlServer.FunctionalTests\QuerySqlServerTest.cs(39,0): at Microsoft.EntityFrameworkCore.SqlServer.FunctionalTests.QuerySqlServerTest.Lifting_when_subquery_nested_order_by_anonymous()

This exception happens because we do order by on client. The value comes from offset value buffer but projection shaper still tries to pick value from 0th index.

[tuespetre]

I can take this one if you want, @smitpatel

[smitpatel]

@tuespetre - Sure. I haven't started work on this yet so you can go ahead with this. Thanks.

[anpete]

@tuespetre Any progress on this? 😁

[tuespetre]

@anpete impeccable timing! Waiting on tests to finish running before pushing up the PR.

[anpete]

🎆 🍾