support for Any in Linq Provider

lotosbin · Jul 9, 2010 · ab62f7e · ab62f7e
1 parent b442b0c
commit ab62f7e
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Showing 4 changed files with 29 additions and 11 deletions.
diff --git a/source/MongoDB.Tests/IntegrationTests/Linq/MongoQueryTests.cs b/source/MongoDB.Tests/IntegrationTests/Linq/MongoQueryTests.cs
@@ -63,6 +63,14 @@ public override void TestSetup()
                 true);
         }
 
+        [Test]
+        public void Any()
+        {
+            var anyone = Collection.Linq().Any(x => x.Age <= 21);
+
+            Assert.IsTrue(anyone);
+        }
+
         [Test]
         public void Boolean()
         {

diff --git a/source/MongoDB/Linq/MongoQueryProvider.cs b/source/MongoDB/Linq/MongoQueryProvider.cs
@@ -160,7 +160,7 @@ private Expression BuildExecutionPlan(Expression expression)
             return new ExecutionBuilder().Build(projection, provider);
         }
 
-        private ProjectionExpression Translate(Expression expression)
+        private Expression Translate(Expression expression)
         {
             var rootQueryable = new RootQueryableFinder().Find(expression);
             var elementType = ((IQueryable)((ConstantExpression)rootQueryable).Value).ElementType;
@@ -177,7 +177,7 @@ private ProjectionExpression Translate(Expression expression)
             expression = new RedundantFieldRemover().Remove(expression);
             expression = new RedundantSubqueryRemover().Remove(expression);
 
-            return (ProjectionExpression)expression;
+            return expression;
         }
 
         /// <summary>

diff --git a/source/MongoDB/Linq/Translators/MongoQueryObjectBuilder.cs b/source/MongoDB/Linq/Translators/MongoQueryObjectBuilder.cs
@@ -9,7 +9,7 @@ internal class MongoQueryObjectBuilder : MongoExpressionVisitor
         private MongoQueryObject _queryObject;
         private QueryAttributes _queryAttributes;
 
-        internal MongoQueryObject Build(ProjectionExpression expression)
+        internal MongoQueryObject Build(Expression expression)
         {
             _queryObject = new MongoQueryObject();
             _queryAttributes = new QueryAttributesGatherer().Gather(expression);

diff --git a/source/MongoDB/Linq/Translators/QueryBinder.cs b/source/MongoDB/Linq/Translators/QueryBinder.cs
@@ -128,6 +128,11 @@ protected override Expression VisitMethodCall(MethodCallExpression m)
                 {
                     switch (m.Method.Name)
                     {
+                        case "Any":
+                            if (m.Arguments.Count == 1)
+                                return BindAny(m.Arguments[0], null, m == _root);
+                            else
+                                return BindAny(m.Arguments[0], (LambdaExpression)StripQuotes(m.Arguments[1]), m == _root);
                         case "Where":
                             return BindWhere(m.Type, m.Arguments[0], (LambdaExpression)StripQuotes(m.Arguments[1]));
                         case "Select":
@@ -273,16 +278,21 @@ private Expression BindAggregate(Expression source, MethodInfo method, LambdaExp
             return subquery;
         }
 
-        private Expression BindAny(Expression source, LambdaExpression predicate)
+        private Expression BindAny(Expression source, LambdaExpression predicate, bool isRoot)
         {
             var projection = VisitSequence(source);
-            _map[predicate.Parameters[0]] = projection.Projector;
-            var where = Visit(predicate.Body);
-            var alias = new Alias();
-            var fieldProjection = _projector.ProjectFields(projection.Projector, alias, projection.Source.Alias);
-            return new ProjectionExpression(
-                new SelectExpression(alias, fieldProjection.Fields, projection.Source, where),
-                fieldProjection.Projector);
+            var sourceType = projection.Projector.Type;
+
+            MethodInfo method = typeof(Queryable)
+                .GetMethods(BindingFlags.Public | BindingFlags.Static)
+                .Where(m => m.Name == "Count")
+                .Single(m => m.GetParameters().Length == (predicate == null ? 1 : 2))
+                .GetGenericMethodDefinition().MakeGenericMethod(sourceType);
+
+            var expression = BindAggregate(source, method, predicate, isRoot);
+
+            return Expression.GreaterThan(
+                expression, Expression.Constant(0));
         }
 
         private Expression BindDistinct(Expression source)