private static IQueryable <T> IncludeOptimizedSingle <T, TChild>(this IQueryable <T> query, Expression <Func <T, TChild> > queryIncludeFilter) where T : class where TChild : class
{
// INCLUDE sub path
query = QueryIncludeFilterIncludeSubPath.IncludeSubPath(query, queryIncludeFilter);
// GET query root
var includeOrderedQueryable = query as QueryIncludeFilterParentQueryable <T> ?? new QueryIncludeFilterParentQueryable <T>(query);
// ADD sub query
includeOrderedQueryable.Childs.Add(new QueryIncludeFilterChild <T, TChild>(queryIncludeFilter));
// RETURN root
return(includeOrderedQueryable);
}
/// <summary>Executes the given expression.</summary>
/// <exception cref="Exception">Thrown when an exception error condition occurs.</exception>
/// <typeparam name="TResult">Type of the result.</typeparam>
/// <param name="expression">The expression to execute.</param>
/// <returns>The object returned by the execution of the expression.</returns>
public TResult Execute <TResult>(Expression expression)
{
var methodCall = expression as MethodCallExpression;
if (methodCall == null)
{
throw new Exception(ExceptionMessage.GeneralException);
}
if (methodCall.Method.Name == "All" ||
methodCall.Method.Name == "Any" ||
methodCall.Method.Name == "Average" ||
methodCall.Method.Name == "Contains" ||
methodCall.Method.Name == "Count" ||
methodCall.Method.Name == "LongCount" ||
methodCall.Method.Name == "Max" ||
methodCall.Method.Name == "Min" ||
methodCall.Method.Name == "SequenceEqual" ||
methodCall.Method.Name == "Sum")
{
return(OriginalProvider.Execute <TResult>(expression));
}
QueryIncludeFilterIncludeSubPath.RemoveLazyChild(CurrentQueryable);
var currentQuery = CurrentQueryable;
var currentMethod = methodCall.Method.GetGenericMethodDefinition();
// CHECK if the internal expression can be supported
var isExpressionSupported = false;
var firstExpression = methodCall.Arguments.FirstOrDefault(x => x.Type.IsSubclassOf(typeof(Expression)));
if (firstExpression != null && methodCall.Arguments.Count == 2)
{
var quoteExpression = ((UnaryExpression)firstExpression).Operand;
var lambdaExpression = quoteExpression as LambdaExpression;
if (lambdaExpression != null)
{
if (lambdaExpression.Type == typeof(Func <,>).MakeGenericType(currentQuery.ElementType, typeof(bool)))
{
var method = typeof(Queryable).GetMethods().First(x => x.Name == "Where" && x.GetParameters()[1].ParameterType.GetGenericArguments()[0].GetGenericArguments().Length == 2);
var methodGeneric = method.MakeGenericMethod(currentQuery.ElementType);
currentQuery = (QueryIncludeFilterParentQueryable <T>)methodGeneric.Invoke(null, new object[] { currentQuery, lambdaExpression });
currentMethod = typeof(Queryable).GetMethods().FirstOrDefault(x => x.Name == currentMethod.Name && x.GetParameters().Length == 1);
isExpressionSupported = currentMethod != null;
}
}
}
if (firstExpression != null && !isExpressionSupported)
{
throw new Exception(ExceptionMessage.QueryIncludeFilter_ArgumentExpression);
}
// CREATE the new query by selecting included entities in an anonymous type
var newQuery = currentQuery;
// REPLACE the first argument with the new query expression
var arguments = methodCall.Arguments.ToList();
arguments[0] = newQuery.Expression;
// REMOVE the last argument if a "Predicate" method was previously used
if (firstExpression != null)
{
arguments.RemoveAt(1);
}
#if EFCORE_3X
// RESOLE parent queries using .FutureValue();
var immediateQuery = new EntityQueryable <TResult>((IAsyncQueryProvider)OriginalProvider, expression);
#else
// RESOLE parent queries using .FutureValue();
var immediateQuery = new EntityQueryable <TResult>((IAsyncQueryProvider)OriginalProvider);
var expressionProperty = typeof(QueryableBase <>).MakeGenericType(typeof(TResult)).GetProperty("Expression", BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
expressionProperty.SetValue(immediateQuery, expression);
#endif
object value = null;
DbContext context = null;
if (currentQuery.OriginalQueryable.IsInMemoryQueryContext())
{
context = currentQuery.OriginalQueryable.GetInMemoryContext();
}
else
{
// MODIFY query if necessary
context = currentQuery.OriginalQueryable.GetDbContext();
}
if (QueryIncludeFilterManager.AllowQueryBatch)
{
var futureValue = immediateQuery.FutureValue();
// RESOLVE child queries using .Future()
{
// MODIFY query if necessary
var keyNames = context.Model.FindEntityType(typeof(TResult).DisplayName(true))
.GetKeys().ToList()[0]
.Properties.Select(x => x.Name).ToArray();
var currentNewQuery = methodCall.Method.Name == "First" || methodCall.Method.Name == "FirstOrDefault" ? currentQuery.AddToRootOrAppendOrderBy(keyNames).Take(1) :
methodCall.Method.Name == "Last" || methodCall.Method.Name == "LastOrDefault" ? currentQuery.AddToRootOrAppendOrderBy(keyNames).Reverse().Take(1) :
currentQuery;
currentQuery.CreateQueryable(currentNewQuery);
}
value = futureValue.Value;
}
else
{
// TODO: Find a better way
value = immediateQuery.FutureValue().Value;
//value = immediateQuery.Execute(objectQuery.MergeOption).FirstOrDefault();
// RESOLVE child queries using .Future()
{
// MODIFY query if necessary
var keyNames = context.Model.FindEntityType(typeof(TResult).DisplayName(true))
.GetKeys().ToList()[0]
.Properties.Select(x => x.Name).ToArray();
var currentNewQuery = methodCall.Method.Name == "First" || methodCall.Method.Name == "FirstOrDefault" ?
currentQuery.AddToRootOrAppendOrderBy(keyNames).Take(1) :
methodCall.Method.Name == "Last" || methodCall.Method.Name == "LastOrDefault" ?
currentQuery.AddToRootOrAppendOrderBy(keyNames).Reverse().Take(1) :
currentQuery;
currentQuery.CreateQueryable(currentNewQuery);
}
}
// EXECUTE the new expression
//var value = QueryIncludeFilterManager.AllowQueryBatch ? immediateQuery.FutureValue().Value : immediateQuery.FirstOrDefault();
// CHECK if a value has been returned
if (value == null)
{
return((TResult)(object)null);
}
// FIX null collection
QueryIncludeFilterNullCollection.NullCollectionToEmpty(value, CurrentQueryable.Childs);
return((TResult)value);
}
/// <summary>Enumerates create enumerable in this collection.</summary>
/// <exception cref="Exception">Thrown when an exception error condition occurs.</exception>
/// <returns>
/// An enumerator that allows foreach to be used to process create enumerable in this collection.
/// </returns>
public IEnumerable <T> CreateEnumerable()
{
//var objectQuery = OriginalQueryable.GetObjectQuery();
//if (objectQuery.MergeOption == MergeOption.NoTracking)
//{
// objectQuery.MergeOption = MergeOption.AppendOnly;
// var newContext = QueryIncludeFilterManager.DbContextFactory(objectQuery.Context.GetDbContext()).GetObjectContext();
// // CHANGE the context under the objectQuery
// {
// var internalQueryProperty = OriginalQueryable.GetType().GetProperty("InternalQuery", BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
// var internalQuery = internalQueryProperty.GetValue(OriginalQueryable);
// //var internalQueryProperty = typeof(DbQuery).GetProperty("InternalQuery", BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
// //var internalQuery = internalQueryProperty.GetValue(OriginalQueryable, null);
// var stateField = typeof(ObjectQuery).GetField("_state", BindingFlags.NonPublic | BindingFlags.Instance);
// var state = stateField.GetValue(objectQuery);
// var assembly = typeof(ObjectQuery).Assembly;
// var objectQueryState = assembly.GetType("System.Data.Entity.Core.Objects.Internal.ObjectQueryState");
// var contextField = objectQueryState.GetField("_context", BindingFlags.NonPublic | BindingFlags.Instance);
// contextField.SetValue(state, newContext);
// var expressionField = state.GetType().GetField("_expression", BindingFlags.NonPublic | BindingFlags.Instance);
// var expression = (Expression)expressionField.GetValue(state);
// var visitor = new QueryIncludeFilterExpressionReduceVisitor2();
// expression = visitor.Visit(expression);
// }
//}
QueryIncludeFilterIncludeSubPath.RemoveLazyChild(this);
// MODIFY query if necessary
var context = OriginalQueryable.GetDbContext();
var keyNames = context.Model.FindEntityType(typeof(T).DisplayName(true))
.GetKeys().ToList()[0]
.Properties.Select(x => x.Name).ToArray();
//var newQuery = OriginalQueryable.AddToRootOrAppendOrderBy(keyNames).Select(x => x);
var newQuery = OriginalQueryable.AddToRootOrAppendOrderBy(keyNames);
List <T> list;
if (QueryIncludeFilterManager.AllowQueryBatch)
{
var future = newQuery.Future();
foreach (var child in Childs)
{
child.CreateIncludeQuery(newQuery);
}
list = future.ToList();
}
else
{
list = newQuery.ToList();
foreach (var child in Childs)
{
child.CreateIncludeQuery(newQuery);
}
}
// FIX collection null
QueryIncludeFilterNullCollection.NullCollectionToEmpty(list, Childs);
return(list);
}
