/// <summary>
/// This API supports the Entity Framework Core infrastructure and is not intended to be used
/// directly from your code. This API may change or be removed in future releases.
/// </summary>
protected override Expression VisitMethodCall(MethodCallExpression methodCallExpression)
{
var newMethodCallExpression = (MethodCallExpression)base.VisitMethodCall(methodCallExpression);
Expression newLeftExpression = null;
Expression newRightExpression = null;
if (newMethodCallExpression.Method.Name == nameof(object.Equals) &&
newMethodCallExpression.Object != null &&
newMethodCallExpression.Arguments.Count == 1)
{
newLeftExpression = newMethodCallExpression.Object;
newRightExpression = newMethodCallExpression.Arguments[0];
}
if (newMethodCallExpression.Method.Equals(_objectEqualsMethodInfo))
{
newLeftExpression = newMethodCallExpression.Arguments[0];
newRightExpression = newMethodCallExpression.Arguments[1];
}
if (newLeftExpression != null &&
newRightExpression != null)
{
var isLeftNullConstant = newLeftExpression.IsNullConstantExpression();
var isRightNullConstant = newRightExpression.IsNullConstantExpression();
if (isLeftNullConstant && isRightNullConstant)
{
return(newMethodCallExpression);
}
if (isLeftNullConstant || isRightNullConstant)
{
var result = RewriteNullEquality(
ExpressionType.Equal, isLeftNullConstant ? newRightExpression : newLeftExpression);
if (result != null)
{
return(result);
}
}
var leftEntityType = _model.FindEntityType(newLeftExpression.Type)
?? MemberAccessBindingExpressionVisitor.GetEntityType(newLeftExpression, _queryCompilationContext);
var rightEntityType = _model.FindEntityType(newRightExpression.Type)
?? MemberAccessBindingExpressionVisitor.GetEntityType(newRightExpression, _queryCompilationContext);
if (leftEntityType != null && rightEntityType != null)
{
if (leftEntityType.RootType() == rightEntityType.RootType())
{
var result = RewriteEntityEquality(ExpressionType.Equal, newLeftExpression, newRightExpression);
if (result != null)
{
return(result);
}
}
else
{
return(Expression.Constant(false));
}
}
}
return(newMethodCallExpression);
}
/// <summary>
/// This API supports the Entity Framework Core infrastructure and is not intended to be used
/// directly from your code. This API may change or be removed in future releases.
/// </summary>
protected override Expression VisitBinary(BinaryExpression binaryExpression)
{
Check.NotNull(binaryExpression, nameof(binaryExpression));
var newBinaryExpression = (BinaryExpression)base.VisitBinary(binaryExpression);
if (binaryExpression.NodeType == ExpressionType.Equal ||
binaryExpression.NodeType == ExpressionType.NotEqual)
{
var isLeftNullConstant = newBinaryExpression.Left.IsNullConstantExpression();
var isRightNullConstant = newBinaryExpression.Right.IsNullConstantExpression();
if (isLeftNullConstant && isRightNullConstant)
{
return(newBinaryExpression);
}
var isNullComparison = isLeftNullConstant || isRightNullConstant;
var nonNullExpression = isLeftNullConstant ? newBinaryExpression.Right : newBinaryExpression.Left;
var qsre = nonNullExpression as QuerySourceReferenceExpression;
var leftProperties = MemberAccessBindingExpressionVisitor.GetPropertyPath(
newBinaryExpression.Left, _queryCompilationContext, out var leftNavigationQsre);
var rightProperties = MemberAccessBindingExpressionVisitor.GetPropertyPath(
newBinaryExpression.Right, _queryCompilationContext, out var rightNavigationQsre);
if (isNullComparison)
{
var nonNullNavigationQsre = isLeftNullConstant ? rightNavigationQsre : leftNavigationQsre;
var nonNullproperties = isLeftNullConstant ? rightProperties : leftProperties;
if (IsCollectionNavigation(nonNullNavigationQsre, nonNullproperties))
{
// collection navigation is only null if its parent entity is null (null propagation thru navigation)
// it is probable that user wanted to see if the collection is (not) empty, log warning suggesting to use Any() instead.
_queryCompilationContext.Logger
.PossibleUnintendedCollectionNavigationNullComparisonWarning(nonNullproperties);
var callerExpression = CreateCollectionCallerExpression(nonNullNavigationQsre, nonNullproperties);
return(Visit(Expression.MakeBinary(newBinaryExpression.NodeType, callerExpression, Expression.Constant(null))));
}
}
var collectionNavigationComparison = TryRewriteCollectionNavigationComparison(
newBinaryExpression.Left,
newBinaryExpression.Right,
newBinaryExpression.NodeType,
leftNavigationQsre,
rightNavigationQsre,
leftProperties,
rightProperties);
if (collectionNavigationComparison != null)
{
return(collectionNavigationComparison);
}
// If a reference navigation is being compared to null then don't rewrite
if (isNullComparison &&
qsre == null)
{
return(newBinaryExpression);
}
var entityType = _queryCompilationContext.Model.FindEntityType(nonNullExpression.Type);
if (entityType == null)
{
if (qsre != null)
{
entityType = _queryCompilationContext.FindEntityType(qsre.ReferencedQuerySource);
}
else
{
entityType = MemberAccessBindingExpressionVisitor.GetEntityType(
nonNullExpression, _queryCompilationContext);
}
}
if (entityType != null)
{
return(CreateKeyComparison(
entityType,
newBinaryExpression.Left,
newBinaryExpression.Right,
newBinaryExpression.NodeType,
isLeftNullConstant,
isRightNullConstant,
isNullComparison));
}
}
return(newBinaryExpression);
}
