Merge pull request #427 from hazzik/NH-3727

NH-3727 - Fix re-using Criteria with SubqueryProjection

Author: hazzik

src/NHibernate.Test/NHSpecificTest/NH3727/Entity.cs

@@ -0,0 +1,7 @@
+namespace NHibernate.Test.NHSpecificTest.NH3727
+{
+	class Entity
+	{
+		public virtual int Id { get; set; }
+	}
+}

src/NHibernate.Test/NHSpecificTest/NH3727/FixtureByCode.cs

@@ -0,0 +1,83 @@
+using System.Collections.Generic;
+using System.Linq;
+using NHibernate.Cfg.MappingSchema;
+using NHibernate.Criterion;
+using NHibernate.Mapping.ByCode;
+using NHibernate.Transform;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.NH3727
+{
+	public class ByCodeFixture : TestCaseMappingByCode
+	{
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+			mapper.Class<Entity>(rc =>
+			{
+				rc.Id(x => x.Id);
+			});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+
+		[Test]
+		public void QueryOverWithSubqueryProjectionCanBeExecutedMoreThanOnce()
+		{
+			using (ISession session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				const int parameter1 = 111;
+
+				var countSubquery = QueryOver.Of<Entity>()
+						.Where(x => x.Id == parameter1) //any condition which makes output SQL has parameter
+						.Select(Projections.RowCount())
+						;
+
+				var originalQueryOver = session.QueryOver<Entity>()
+											   .SelectList(l => l
+																	.Select(x => x.Id)
+																	.SelectSubQuery(countSubquery)
+												)
+											   .TransformUsing(Transformers.ToList);
+
+				var objects = originalQueryOver.List<object>();
+
+				Assert.DoesNotThrow(() => originalQueryOver.List<object>(), "Second try to execute QueryOver thrown exception.");
+			}
+		}
+
+		[Test]
+		public void ClonedQueryOverExecutionMakesOriginalQueryOverNotWorking()
+		{
+			// Projections are copied by clone operation. 
+			// SubqueryProjection use SubqueryExpression which holds CriteriaQueryTranslator (class SubqueryExpression { private CriteriaQueryTranslator innerQuery; })
+			// So given CriteriaQueryTranslator is used twice. 
+			// Since CriteriaQueryTranslator has CollectedParameters collection, second execution of the Criteria does not fit SqlCommand parameters.
+
+			using (ISession session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				const int parameter1 = 111;
+
+				var countSubquery = QueryOver.Of<Entity>()
+						.Where(x => x.Id == parameter1) //any condition which makes output SQL has parameter
+						.Select(Projections.RowCount())
+						;
+
+				var originalQueryOver = session.QueryOver<Entity>()
+											   //.Where(x => x.Id == parameter2)
+											   .SelectList(l => l
+																	.Select(x => x.Id)
+																	.SelectSubQuery(countSubquery)
+												)
+											   .TransformUsing(Transformers.ToList);
+
+				var clonedQueryOver = originalQueryOver.Clone();
+				clonedQueryOver.List<object>();
+
+				Assert.DoesNotThrow(() => originalQueryOver.List<object>(), "Cloned QueryOver execution caused source QueryOver throw exception when executed.");
+			}
+		}
+	}
+}

src/NHibernate.Test/NHibernate.Test.csproj

@@ -869,6 +869,8 @@
     <Compile Include="NHSpecificTest\NH3634\CachedPerson.cs" />
     <Compile Include="NHSpecificTest\NH3634\CachedPersonMapper.cs" />
     <Compile Include="NHSpecificTest\NH3634\PersonMapper.cs" />
+    <Compile Include="NHSpecificTest\NH3727\Entity.cs" />
+    <Compile Include="NHSpecificTest\NH3727\FixtureByCode.cs" />
     <Compile Include="NHSpecificTest\NH646\Domain.cs" />
     <Compile Include="NHSpecificTest\NH646\Fixture.cs" />
     <Compile Include="NHSpecificTest\NH3234\Fixture.cs" />

src/NHibernate/Criterion/SubqueryExpression.cs

@@ -20,10 +20,8 @@ public abstract class SubqueryExpression : AbstractCriterion
 		private QueryParameters parameters;
 		private IType[] types;
 
-		[NonSerialized] private CriteriaQueryTranslator innerQuery;
-
 		protected SubqueryExpression(String op, String quantifier, DetachedCriteria dc)
-			:this(op, quantifier, dc, true)
+			: this(op, quantifier, dc, true)
 		{
 		}
 
@@ -44,16 +42,23 @@ public IType[] GetTypes()
 
 		public override SqlString ToSqlString(ICriteria criteria, ICriteriaQuery criteriaQuery, IDictionary<string, IFilter> enabledFilters)
 		{
-			InitializeInnerQueryAndParameters(criteriaQuery);
+			ISessionFactoryImplementor factory = criteriaQuery.Factory;
+
+			var innerQuery = new CriteriaQueryTranslator(
+				factory,
+				criteriaImpl, //implicit polymorphism not supported (would need a union)
+				criteriaImpl.EntityOrClassName,
+				criteriaQuery.GenerateSQLAlias(),
+				criteriaQuery);
+
+			types = innerQuery.HasProjection ? innerQuery.ProjectedTypes : null;
 
 			if (innerQuery.HasProjection == false)
 			{
 				throw new QueryException("Cannot use subqueries on a criteria without a projection.");
 			}
 
-			ISessionFactoryImplementor factory = criteriaQuery.Factory;
-
-			IOuterJoinLoadable persister = (IOuterJoinLoadable)factory.GetEntityPersister(criteriaImpl.EntityOrClassName);
+			IOuterJoinLoadable persister = (IOuterJoinLoadable) factory.GetEntityPersister(criteriaImpl.EntityOrClassName);
 
 			//patch to generate joins on subqueries
 			//stolen from CriteriaLoader
@@ -73,11 +78,6 @@ public override SqlString ToSqlString(ICriteria criteria, ICriteriaQuery criteri
 				sql = factory.Dialect.GetLimitString(sql, offset, limit, offsetParameter, limitParameter);
 			}
 
-			// during CriteriaImpl.Clone we are doing a shallow copy of each criterion.
-			// this is not a problem for common criterion but not for SubqueryExpression because here we are holding the state of inner CriteriaTraslator (ICriteriaQuery).
-			// After execution (ToSqlString) we have to clean the internal state because the next execution may be performed in a different tree reusing the same istance of SubqueryExpression.
-			innerQuery = null;
-
 			SqlStringBuilder buf = new SqlStringBuilder().Add(ToLeftSqlString(criteria, criteriaQuery));
 			if (op != null)
 			{
@@ -88,7 +88,7 @@ public override SqlString ToSqlString(ICriteria criteria, ICriteriaQuery criteri
 			{
 				buf.Add(quantifier).Add(" ");
 			}
-			
+
 			buf.Add("(").Add(sql).Add(")");
 
 			if (quantifier != null && prefixOp == false)
@@ -101,9 +101,9 @@ public override SqlString ToSqlString(ICriteria criteria, ICriteriaQuery criteri
 
 		public override string ToString()
 		{
-			if(prefixOp)
+			if (prefixOp)
 				return string.Format("{0} {1} ({2})", op, quantifier, criteriaImpl);
-			
+
 			return string.Format("{0} ({1}) {2}", op, criteriaImpl, quantifier);
 		}
 
@@ -117,23 +117,6 @@ public override IProjection[] GetProjections()
 			return null;
 		}
 
-		public void InitializeInnerQueryAndParameters(ICriteriaQuery criteriaQuery)
-		{
-			if (innerQuery == null)
-			{
-				ISessionFactoryImplementor factory = criteriaQuery.Factory;
-
-				innerQuery = new CriteriaQueryTranslator(
-					factory,
-					criteriaImpl, //implicit polymorphism not supported (would need a union)
-					criteriaImpl.EntityOrClassName,
-					criteriaQuery.GenerateSQLAlias(),
-					criteriaQuery);
-
-				types = innerQuery.HasProjection ? innerQuery.ProjectedTypes : null;
-			}
-		}
-
 		public ICriteria Criteria
 		{
 			// NH-1146

src/NHibernate/Criterion/SubqueryProjection.cs

@@ -13,7 +13,7 @@ namespace NHibernate.Criterion
 	[Serializable]
 	public class SubqueryProjection : SimpleProjection
 	{
-		private SelectSubqueryExpression _subQuery;
+		private readonly SelectSubqueryExpression _subQuery;
 
 		protected internal SubqueryProjection(SelectSubqueryExpression subquery)
 		{
@@ -37,14 +37,13 @@ public override bool IsAggregate
 
 		public override IType[] GetTypes(ICriteria criteria, ICriteriaQuery criteriaQuery)
 		{
-			_subQuery.InitializeInnerQueryAndParameters(criteriaQuery);
 			return _subQuery.GetTypes();
 		}
 
 		public override SqlString ToSqlString(ICriteria criteria, int loc, ICriteriaQuery criteriaQuery, IDictionary<string, IFilter> enabledFilters)
 		{
-			SqlString sqlStringSubquery = _subQuery.ToSqlString(criteria, criteriaQuery, enabledFilters);
-			return sqlStringSubquery.Append(new SqlString(new object[] { " as y", loc.ToString(), "_" } ));
+			return _subQuery.ToSqlString(criteria, criteriaQuery, enabledFilters)
+				.Append(new SqlString(" as y", loc.ToString(), "_"));
 		}
 
 		public override SqlString ToGroupSqlString(ICriteria criteria, ICriteriaQuery criteriaQuery, IDictionary<string, IFilter> enabledFilters)