Reintroduce the SkipTakeCollapsingExpressionVisitor (#200)

src/EFCore.Jet.Data/JetCommand.cs

@@ -554,12 +554,11 @@ namespace EntityFrameworkCore.Jet.Data
             // in TOP clauses.
             var parameters = InnerCommand.Parameters.Cast<DbParameter>()
                 .ToList();
+            var lastCommandText = InnerCommand.CommandText;
+            var commandText = lastCommandText;
 
             if (parameters.Count > 0)
             {
-                var lastCommandText = InnerCommand.CommandText;
-                var commandText = lastCommandText;
-
                 while ((commandText = _topMultiParameterRegularExpression.Replace(
                            lastCommandText,
                            match =>
@@ -587,24 +586,23 @@ namespace EntityFrameworkCore.Jet.Data
                     lastCommandText = commandText;
                 }
 
-                while ((commandText = _topMultiArgumentRegularExpression.Replace(
-                           lastCommandText,
-                           match =>
-                           {
-                               var first = match.Groups["first"];
-                               var sec = match.Groups["sec"];
-                               return (Convert.ToInt32(first.Value) + Convert.ToInt32(sec.Value)).ToString();
-                           },
-                           1)) != lastCommandText)
-                {
-                    lastCommandText = commandText;
-                }
-
-                InnerCommand.CommandText = commandText;
-
                 InnerCommand.Parameters.Clear();
                 InnerCommand.Parameters.AddRange(parameters.ToArray());
             }
+            while ((commandText = _topMultiArgumentRegularExpression.Replace(
+                       lastCommandText,
+                       match =>
+                       {
+                           var first = match.Groups["first"];
+                           var sec = match.Groups["sec"];
+                           return (Convert.ToInt32(first.Value) + Convert.ToInt32(sec.Value)).ToString();
+                       },
+                       1)) != lastCommandText)
+            {
+                lastCommandText = commandText;
+            }
+
+            InnerCommand.CommandText = commandText;
         }
 
         private void ModifyOuterSelectTopValueForOuterSelectSkipEmulationViaDataReader()

src/EFCore.Jet/Query/Internal/JetParameterBasedSqlProcessor.cs

@@ -40,19 +40,19 @@ public class JetParameterBasedSqlProcessor : RelationalParameterBasedSqlProcesso
         IReadOnlyDictionary<string, object?> parametersValues,
         out bool canCache)
     {
-        queryExpression = base.Optimize(queryExpression, parametersValues, out canCache);
+        var optimizedQueryExpression = base.Optimize(queryExpression, parametersValues, out canCache);
 
-        /*optimizedQueryExpression = new SkipTakeCollapsingExpressionVisitor(Dependencies.SqlExpressionFactory)
+        optimizedQueryExpression = new SkipTakeCollapsingExpressionVisitor(Dependencies.SqlExpressionFactory)
-            .Process(optimizedQueryExpression, parametersValues, out var canCache2);*/
+            .Process(optimizedQueryExpression, parametersValues, out var canCache2);
 
-        //canCache &= canCache2;
+        canCache &= canCache2;
 
-        queryExpression = new SearchConditionConvertingExpressionVisitor(Dependencies.SqlExpressionFactory).Visit(queryExpression);
+        optimizedQueryExpression = new SearchConditionConvertingExpressionVisitor(Dependencies.SqlExpressionFactory).Visit(optimizedQueryExpression);
 
         // Run the compatibility checks as late in the query pipeline (before the actual SQL translation happens) as reasonable.
-        queryExpression = new JetCompatibilityExpressionVisitor().Visit(queryExpression);
+        optimizedQueryExpression = new JetCompatibilityExpressionVisitor().Visit(optimizedQueryExpression);
 
-        return queryExpression;
+        return optimizedQueryExpression;
     }
 
     /// <inheritdoc />

src/EFCore.Jet/Query/Internal/SkipTakeCollapsingExpressionVisitor.cs

@@ -0,0 +1,106 @@
+using System.Collections.Generic;
+using System.Linq.Expressions;
+using Microsoft.EntityFrameworkCore.Query;
+using Microsoft.EntityFrameworkCore.Query.SqlExpressions;
+
+namespace EntityFrameworkCore.Jet.Query.Internal;
+
+/// <summary>
+///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+///     any release. You should only use it directly in your code with extreme caution and knowing that
+///     doing so can result in application failures when updating to a new Entity Framework Core release.
+/// </summary>
+public class SkipTakeCollapsingExpressionVisitor : ExpressionVisitor
+{
+    private readonly ISqlExpressionFactory _sqlExpressionFactory;
+
+    private IReadOnlyDictionary<string, object?> _parameterValues;
+    private bool _canCache;
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public SkipTakeCollapsingExpressionVisitor(ISqlExpressionFactory sqlExpressionFactory)
+    {
+        _sqlExpressionFactory = sqlExpressionFactory;
+        _parameterValues = null!;
+    }
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public virtual Expression Process(
+        Expression queryExpression,
+        IReadOnlyDictionary<string, object?> parametersValues,
+        out bool canCache)
+    {
+        _parameterValues = parametersValues;
+        _canCache = true;
+
+        var result = Visit(queryExpression);
+
+        canCache = _canCache;
+
+        return result;
+    }
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    protected override Expression VisitExtension(Expression extensionExpression)
+    {
+        if (extensionExpression is SelectExpression selectExpression)
+        {
+            if (IsZero(selectExpression.Limit))
+            {
+                var result = selectExpression.Update(
+                    selectExpression.Projection,
+                    selectExpression.Tables,
+                    selectExpression.GroupBy.Count > 0 ? selectExpression.Predicate : _sqlExpressionFactory.Constant(false),
+                    selectExpression.GroupBy,
+                    selectExpression.GroupBy.Count > 0 ? _sqlExpressionFactory.Constant(false) : null,
+                    new List<OrderingExpression>(0),
+                    limit: null,
+                    offset: null);
+                return base.VisitExtension(result);
+            }
+
+            bool IsZero(SqlExpression? sqlExpression)
+            {
+                switch (sqlExpression)
+                {
+                    case SqlConstantExpression { Value: int intValue }:
+                        return intValue == 0;
+                    case SqlParameterExpression parameter:
+                        _canCache = false;
+                        return _parameterValues[parameter.Name] is 0;
+                    case SqlBinaryExpression { Left: SqlConstantExpression left, Right: SqlConstantExpression right }:
+                        return left.Value is int leftValue && right.Value is int rightValue && leftValue + rightValue == 0;
+                    case SqlBinaryExpression { Left: SqlParameterExpression left, Right: SqlConstantExpression right }:
+                        _canCache = false;
+                        return _parameterValues[left.Name] is 0 && right.Value is int and 0;
+                    case SqlBinaryExpression { Left: SqlConstantExpression left, Right: SqlParameterExpression right }:
+                        _canCache = false;
+                        return _parameterValues[right.Name] is 0 && left.Value is int and 0;
+                    case SqlBinaryExpression { Left: SqlParameterExpression left, Right: SqlParameterExpression right }:
+                        _canCache = false;
+                        return _parameterValues[left.Name] is 0 && _parameterValues[right.Name] is 0;
+                    default:
+                        return false;
+                }
+            }
+        }
+
+        return base.VisitExtension(extensionExpression);
+    }
+}

test/EFCore.Jet.FunctionalTests/GreenTests/ace_2010_odbc_x86.txt

@@ -9156,6 +9156,8 @@ EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.Group
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_after_anonymous_projection_and_distinct_followed_by_another_anonymous_projection(async: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_after_predicate_Constant_Select_Sum_Min_Key_Max_Avg(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_after_predicate_Constant_Select_Sum_Min_Key_Max_Avg(isAsync: True)
+EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_aggregate_after_skip_0_take_0(async: False)
+EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_aggregate_after_skip_0_take_0(async: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_aggregate_Contains(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_aggregate_Contains(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_aggregate_followed_another_GroupBy_aggregate(async: False)
@@ -10590,6 +10592,10 @@ EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Shaper_command_caching_when_parameter_names_different(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Shaper_command_caching_when_parameter_names_different(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Single_Predicate_Cancellation
+EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_0_Take_0_works_when_constant(async: False)
+EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_0_Take_0_works_when_constant(async: True)
+EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_0_Take_0_works_when_parameter(async: False)
+EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_0_Take_0_works_when_parameter(async: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_Take_All(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_Take_All(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_Take_Any_with_predicate(isAsync: False)

test/EFCore.Jet.FunctionalTests/GreenTests/ace_2010_oledb_x86.txt

@@ -12068,6 +12068,8 @@ EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.Group
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_after_anonymous_projection_and_distinct_followed_by_another_anonymous_projection(async: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_after_predicate_Constant_Select_Sum_Min_Key_Max_Avg(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_after_predicate_Constant_Select_Sum_Min_Key_Max_Avg(isAsync: True)
+EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_aggregate_after_skip_0_take_0(async: False)
+EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_aggregate_after_skip_0_take_0(async: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_aggregate_Contains(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_aggregate_Contains(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindGroupByQueryJetTest.GroupBy_aggregate_followed_another_GroupBy_aggregate(async: False)
@@ -13522,6 +13524,10 @@ EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Shaper_command_caching_when_parameter_names_different(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Shaper_command_caching_when_parameter_names_different(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Single_Predicate_Cancellation
+EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_0_Take_0_works_when_constant(async: False)
+EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_0_Take_0_works_when_constant(async: True)
+EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_0_Take_0_works_when_parameter(async: False)
+EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_0_Take_0_works_when_parameter(async: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_Take_All(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_Take_All(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.NorthwindMiscellaneousQueryJetTest.Skip_Take_Any_with_predicate(isAsync: False)

test/EFCore.Jet.FunctionalTests/Query/NorthwindGroupByQueryJetTest.cs

@@ -2758,13 +2758,17 @@ INNER JOIN (
 
             AssertSql(
                 """
-SELECT [t].[CustomerID] AS [Key], COUNT(*) AS [Total]
+SELECT `t0`.`CustomerID` AS `Key`, COUNT(*) AS `Total`
 FROM (
-    SELECT [o].[CustomerID]
+    SELECT `t`.`CustomerID`
-    FROM [Orders] AS [o]
+    FROM (
+        SELECT `o`.`CustomerID`
+        FROM `Orders` AS `o`
+        WHERE 0 = 1
+    ) AS `t`
     WHERE 0 = 1
-) AS [t]
+) AS `t0`
-GROUP BY [t].[CustomerID]
+GROUP BY `t0`.`CustomerID`
 """);
         }
 

test/EFCore.Jet.FunctionalTests/Query/NorthwindMiscellaneousQueryJetTest.cs

@@ -5465,18 +5465,31 @@ CROSS APPLY (
 
             AssertSql(
                 """
-SELECT [c].[CustomerID], [c].[Address], [c].[City], [c].[CompanyName], [c].[ContactName], [c].[ContactTitle], [c].[Country], [c].[Fax], [c].[Phone], [c].[PostalCode], [c].[Region]
+SELECT `t0`.`CustomerID`, `t0`.`Address`, `t0`.`City`, `t0`.`CompanyName`, `t0`.`ContactName`, `t0`.`ContactTitle`, `t0`.`Country`, `t0`.`Fax`, `t0`.`Phone`, `t0`.`PostalCode`, `t0`.`Region`
-FROM [Customers] AS [c]
+FROM (
-WHERE 0 = 1
+    SELECT `t`.`CustomerID`, `t`.`Address`, `t`.`City`, `t`.`CompanyName`, `t`.`ContactName`, `t`.`ContactTitle`, `t`.`Country`, `t`.`Fax`, `t`.`Phone`, `t`.`PostalCode`, `t`.`Region`
+    FROM (
+        SELECT `c`.`CustomerID`, `c`.`Address`, `c`.`City`, `c`.`CompanyName`, `c`.`ContactName`, `c`.`ContactTitle`, `c`.`Country`, `c`.`Fax`, `c`.`Phone`, `c`.`PostalCode`, `c`.`Region`
+        FROM `Customers` AS `c`
+        WHERE 0 = 1
+    ) AS `t`
+    WHERE 0 = 1
+) AS `t0`
+ORDER BY `t0`.`CustomerID`
 """,
                 //
                 """
-@__p_0='1'
+SELECT `t0`.`CustomerID`, `t0`.`Address`, `t0`.`City`, `t0`.`CompanyName`, `t0`.`ContactName`, `t0`.`ContactTitle`, `t0`.`Country`, `t0`.`Fax`, `t0`.`Phone`, `t0`.`PostalCode`, `t0`.`Region`
-
+FROM (
-SELECT [c].[CustomerID], [c].[Address], [c].[City], [c].[CompanyName], [c].[ContactName], [c].[ContactTitle], [c].[Country], [c].[Fax], [c].[Phone], [c].[PostalCode], [c].[Region]
+    SELECT TOP 1 `t`.`CustomerID`, `t`.`Address`, `t`.`City`, `t`.`CompanyName`, `t`.`ContactName`, `t`.`ContactTitle`, `t`.`Country`, `t`.`Fax`, `t`.`Phone`, `t`.`PostalCode`, `t`.`Region`
-FROM [Customers] AS [c]
+    FROM (
-ORDER BY [c].[CustomerID]
+        SELECT TOP 2 `c`.`CustomerID`, `c`.`Address`, `c`.`City`, `c`.`CompanyName`, `c`.`ContactName`, `c`.`ContactTitle`, `c`.`Country`, `c`.`Fax`, `c`.`Phone`, `c`.`PostalCode`, `c`.`Region`
-OFFSET @__p_0 ROWS FETCH NEXT @__p_0 ROWS ONLY
+        FROM `Customers` AS `c`
+        ORDER BY `c`.`CustomerID`
+    ) AS `t`
+    ORDER BY `t`.`CustomerID` DESC
+) AS `t0`
+ORDER BY `t0`.`CustomerID`
 """);
         }
 
@@ -5486,16 +5499,20 @@ OFFSET @__p_0 ROWS FETCH NEXT @__p_0 ROWS ONLY
 
             AssertSql(
                 """
-SELECT CASE
+SELECT IIF(EXISTS (
-    WHEN EXISTS (
         SELECT 1
-        FROM [Orders] AS [o]
+        FROM (
-        WHERE 0 = 1) THEN CAST(1 AS bit)
+            SELECT `t`.`OrderID`, `t`.`CustomerID`, `t`.`EmployeeID`, `t`.`OrderDate`
-    ELSE CAST(0 AS bit)
+            FROM (
-END
+                SELECT `o`.`OrderID`, `o`.`CustomerID`, `o`.`EmployeeID`, `o`.`OrderDate`
-FROM [Customers] AS [c]
+                FROM `Orders` AS `o`
-WHERE [c].[CustomerID] LIKE N'F%'
+                WHERE 0 = 1
-ORDER BY [c].[CustomerID]
+            ) AS `t`
+            WHERE 0 = 1
+        ) AS `t0`), TRUE, FALSE)
+FROM `Customers` AS `c`
+WHERE `c`.`CustomerID` LIKE 'F%'
+ORDER BY `c`.`CustomerID`
 """);
         }