added support for elemMatch queries when array elements are documents.

Author: craiggwilson

Driver/Linq/Translators/SelectQuery.cs

@@ -36,6 +36,7 @@ namespace MongoDB.Driver.Linq
  public class SelectQuery : TranslatedQuery
  {
  // private fields
+ private readonly Dictionary<ParameterExpression, IBsonSerializer> _parameterSerializers;
  private LambdaExpression _where;
  private Type _ofType;
  private List<OrderByClause> _orderBy;
@@ -54,6 +55,7 @@ public class SelectQuery : TranslatedQuery
  public SelectQuery(MongoCollection collection, Type documentType)
  : base(collection, documentType)
  {
+ _parameterSerializers = new Dictionary<ParameterExpression, IBsonSerializer>();
  }
 
  // public properties
@@ -247,19 +249,41 @@ private IMongoQuery BuildAnyQuery(MethodCallExpression methodCallExpression)
  if (methodCallExpression.Method.DeclaringType == typeof(Enumerable))
  {
  var arguments = methodCallExpression.Arguments.ToArray();
+ var serializationInfo = GetSerializationInfo(arguments[0]);
+ var itemSerializerProvider = serializationInfo.Serializer as IBsonItemSerializationInfoProvider;
+ if (itemSerializerProvider == null)
+ {
+ return null;
+ }
+
+ var itemSerializationInfo = itemSerializerProvider.GetItemSerializationInfo();
+ if (itemSerializationInfo == null)
+ {
+ return null;
+ }
+
  if (arguments.Length == 1)
  {
- var serializationInfo = GetSerializationInfo(arguments[0]);
- if (serializationInfo != null)
- {
- return Query.And(
- Query.NE(serializationInfo.ElementName, BsonNull.Value),
- Query.Not(serializationInfo.ElementName).Size(0));
- }
+ return Query.And(
+ Query.NE(serializationInfo.ElementName, BsonNull.Value),
+ Query.Not(serializationInfo.ElementName).Size(0));
  }
  else if (arguments.Length == 2)
  {
- throw new NotSupportedException("Enumerable.Any with a predicate is not supported.");
+ if (!(itemSerializationInfo.Serializer is IBsonMemberSerializationInfoProvider))
+ {
+ var message = string.Format("Any is only support for items that serialize into documents. The current serializer is {0} and must implement {1} for participation in Any queries.",
+ BsonUtils.GetFriendlyTypeName(itemSerializationInfo.GetType()),
+ BsonUtils.GetFriendlyTypeName(typeof(IBsonMemberSerializationInfoProvider)));
+ throw new NotSupportedException(message);
+ }
+ var itemSerializer = itemSerializationInfo.Serializer;
+ var lambda = (LambdaExpression)arguments[1];
+ _parameterSerializers[lambda.Parameters[0]] = itemSerializer;
+ var query = BuildQuery(lambda.Body);
+ query = Query.ElemMatch(serializationInfo.ElementName, query);
+ _parameterSerializers.Remove(lambda.Parameters[0]);
+ return query;
  }
  }
  return null;
@@ -1481,7 +1505,9 @@ private BsonSerializationInfo GetSerializationInfo(Expression expression)
  var parameterExpression = expression as ParameterExpression;
  if (parameterExpression != null)
  {
- var serializer = BsonSerializer.LookupSerializer(parameterExpression.Type);
+ IBsonSerializer serializer;
+ if(!_parameterSerializers.TryGetValue(parameterExpression, out serializer))
+ serializer = BsonSerializer.LookupSerializer(parameterExpression.Type);
  return new BsonSerializationInfo(
  null, // elementName
  serializer,
@@ -1493,8 +1519,8 @@ private BsonSerializationInfo GetSerializationInfo(Expression expression)
  parameterExpression = ExpressionParameterFinder.FindParameter(expression);
  if (parameterExpression != null)
  {
- var serializer = BsonSerializer.LookupSerializer(parameterExpression.Type);
- return GetSerializationInfo(serializer, expression);
+ var info = GetSerializationInfo(parameterExpression);
+ return GetSerializationInfo(info.Serializer, expression);
  }
 
  return null;

DriverUnitTests/Linq/SelectQueryTests.cs

@@ -48,6 +48,8 @@ public class C
  public int Y { get; set; }
  [BsonElement("d")]
  public D D { get; set; }
+ [BsonElement("da")]
+ public List<D> DA { get; set; }
  [BsonElement("s")]
  [BsonIgnoreIfNull]
  public string S { get; set; }
@@ -149,11 +151,11 @@ public void Setup()
 
  // documents inserted deliberately out of order to test sorting
  _collection.Drop();
- _collection.Insert(new C { Id = _id2, X = 2, Y = 11, D = new D { Z = 22 }, A = new [] { 2, 3, 4 }, L = new List<int> { 2, 3, 4 } });
+ _collection.Insert(new C { Id = _id2, X = 2, Y = 11, D = new D { Z = 22 }, A = new [] { 2, 3, 4 }, DA = new List<D> { new D { Z = 111 }, new D { Z = 222 } }, L = new List<int> { 2, 3, 4 } });
  _collection.Insert(new C { Id = _id1, X = 1, Y = 11, D = new D { Z = 11 }, S = "abc", SA = new string[] { "Tom", "Dick", "Harry" } });
  _collection.Insert(new C { Id = _id3, X = 3, Y = 33, D = new D { Z = 33 }, B = true, BA = new bool[] { true }, E = E.A, EA = new E[] { E.A, E.B } });
  _collection.Insert(new C { Id = _id5, X = 5, Y = 44, D = new D { Z = 55 }, DBRef = new MongoDBRef("db", "c", 1) });
- _collection.Insert(new C { Id = _id4, X = 4, Y = 44, D = new D { Z = 44 }, S = " xyz " });
+ _collection.Insert(new C { Id = _id4, X = 4, Y = 44, D = new D { Z = 44 }, S = " xyz ", DA = new List<D> { new D { Z = 333 }, new D { Z = 444 } } });
  }
 
  [Test]
@@ -1939,13 +1941,27 @@ where c.A.Any()
  }
 
  [Test]
- [ExpectedException(typeof(NotSupportedException), ExpectedMessage = "Enumerable.Any with a predicate is not supported.")]
+ [ExpectedException(typeof(NotSupportedException), ExpectedMessage = "Any is only support for items that serialize into documents. The current serializer is BsonSerializationInfo and must implement IBsonMemberSerializationInfoProvider for participation in Any queries.")]
  public void TestWhereAAnyWithPredicate()
  {
  var query = from c in _collection.AsQueryable<C>()
  where c.A.Any(a => a > 3)
  select c;
- query.ToList(); // execute query
+
+ var translatedQuery = MongoQueryTranslator.Translate(query);
+ Assert.IsInstanceOf<SelectQuery>(translatedQuery);
+ Assert.AreSame(_collection, translatedQuery.Collection);
+ Assert.AreSame(typeof(C), translatedQuery.DocumentType);
+
+ var selectQuery = (SelectQuery)translatedQuery;
+ Assert.AreEqual("(C c) => Enumerable.Any<Int32>(c.A, (Int32 a) => (a > 3))", ExpressionFormatter.ToString(selectQuery.Where));
+ Assert.IsNull(selectQuery.OrderBy);
+ Assert.IsNull(selectQuery.Projection);
+ Assert.IsNull(selectQuery.Skip);
+ Assert.IsNull(selectQuery.Take);
+
+ Assert.AreEqual("{ \"a\" : 2 }", selectQuery.BuildQuery().ToJson());
+ Assert.AreEqual(1, Consume(query));
  }
 
  [Test]
@@ -3033,6 +3049,29 @@ public void TestWhereDNotEquals11Not()
  Assert.AreEqual(1, Consume(query));
  }
 
+ [Test]
+ public void TestWhereDAAnyWithPredicate()
+ {
+ var query = from c in _collection.AsQueryable<C>()
+ where c.DA.Any(x => x.Z == 333)
+ select c;
+
+ var translatedQuery = MongoQueryTranslator.Translate(query);
+ Assert.IsInstanceOf<SelectQuery>(translatedQuery);
+ Assert.AreSame(_collection, translatedQuery.Collection);
+ Assert.AreSame(typeof(C), translatedQuery.DocumentType);
+
+ var selectQuery = (SelectQuery)translatedQuery;
+ Assert.AreEqual("(C c) => Enumerable.Any<D>(c.DA, (D x) => (x.Z == 333))", ExpressionFormatter.ToString(selectQuery.Where));
+ Assert.IsNull(selectQuery.OrderBy);
+ Assert.IsNull(selectQuery.Projection);
+ Assert.IsNull(selectQuery.Skip);
+ Assert.IsNull(selectQuery.Take);
+
+ Assert.AreEqual("{ \"da\" : { \"$elemMatch\" : { \"z\" : 333 } } }", selectQuery.BuildQuery().ToJson());
+ Assert.AreEqual(1, Consume(query));
+ }
+
  [Test]
  public void TestWhereEAContainsAll()
  {