NH-3787 - Decimal truncation in Linq ternary expression

src/NHibernate.Test/Async/NHSpecificTest/NH3787/TestFixture.cs

@@ -0,0 +1,140 @@
+//------------------------------------------------------------------------------
+// <auto-generated>
+//     This code was generated by AsyncGenerator.
+//
+//     Changes to this file may cause incorrect behavior and will be lost if
+//     the code is regenerated.
+// </auto-generated>
+//------------------------------------------------------------------------------
+
+
+using System.Linq;
+using NHibernate.Criterion;
+using NHibernate.Linq;
+using NHibernate.Transform;
+using NHibernate.Type;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.NH3787
+{
+	using System.Threading.Tasks;
+	[TestFixture]
+	public class TestFixtureAsync : BugTestCase
+	{
+		private const decimal _testRate = 12345.1234567890123M;
+
+		protected override bool AppliesTo(Dialect.Dialect dialect)
+		{
+			return !TestDialect.HasBrokenDecimalType;
+		}
+
+		protected override void OnSetUp()
+		{
+			base.OnSetUp();
+
+			using (var s = OpenSession())
+			using (var t = s.BeginTransaction())
+			{
+				var testEntity = new TestEntity
+				{
+					UsePreviousRate = true,
+					PreviousRate = _testRate,
+					Rate = 54321.1234567890123M
+				};
+				s.Save(testEntity);
+				t.Commit();
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var s = OpenSession())
+			using (var t = s.BeginTransaction())
+			{
+				s.CreateQuery("delete from TestEntity").ExecuteUpdate();
+				t.Commit();
+			}
+		}
+
+		[Test]
+		public async Task TestLinqQueryAsync()
+		{
+			using (var s = OpenSession())
+			using (var t = s.BeginTransaction())
+			{
+				var queryResult = await (s
+					.Query<TestEntity>()
+					.Where(e => e.PreviousRate == _testRate)
+					.ToListAsync());
+
+				Assert.That(queryResult.Count, Is.EqualTo(1));
+				Assert.That(queryResult[0].PreviousRate, Is.EqualTo(_testRate));
+				await (t.CommitAsync());
+			}
+		}
+
+		[Test]
+		public async Task TestLinqProjectionAsync()
+		{
+			using (var s = OpenSession())
+			using (var t = s.BeginTransaction())
+			{
+				var queryResult = await ((from test in s.Query<TestEntity>()
+				                   select new RateDto { Rate = test.UsePreviousRate ? test.PreviousRate : test.Rate }).ToListAsync());
+
+				// Check it has not been truncated to the default scale (10) of NHibernate.
+				Assert.That(queryResult[0].Rate, Is.EqualTo(_testRate));
+				await (t.CommitAsync());
+			}
+		}
+
+		[Test]
+		public async Task TestLinqQueryOnExpressionAsync()
+		{
+			using (var s = OpenSession())
+			using (var t = s.BeginTransaction())
+			{
+				var queryResult = await (s
+					.Query<TestEntity>()
+					.Where(
+						// Without MappedAs, the test fails for SQL Server because it would restrict its parameter to the dialect's default scale.
+						e => (e.UsePreviousRate ? e.PreviousRate : e.Rate) == _testRate.MappedAs(TypeFactory.Basic("decimal(18,13)")))
+					.ToListAsync());
+
+				Assert.That(queryResult.Count, Is.EqualTo(1));
+				Assert.That(queryResult[0].PreviousRate, Is.EqualTo(_testRate));
+				await (t.CommitAsync());
+			}
+		}
+
+		[Test]
+		public async Task TestQueryOverProjectionAsync()
+		{
+			using (var s = OpenSession())
+			using (var t = s.BeginTransaction())
+			{
+				TestEntity testEntity = null;
+
+				var rateDto = new RateDto();
+				//Generated sql
+				//exec sp_executesql N'SELECT (case when this_.UsePreviousRate = @p0 then this_.PreviousRate else this_.Rate end) as y0_ FROM [TestEntity] this_',N'@p0 bit',@p0=1
+				var query = s
+					.QueryOver(() => testEntity)
+					.Select(
+						Projections
+							.Alias(
+								Projections.Conditional(
+									Restrictions.Eq(Projections.Property(() => testEntity.UsePreviousRate), true),
+									Projections.Property(() => testEntity.PreviousRate),
+									Projections.Property(() => testEntity.Rate)),
+								"Rate")
+							.WithAlias(() => rateDto.Rate));
+
+				var queryResult = await (query.TransformUsing(Transformers.AliasToBean<RateDto>()).ListAsync<RateDto>());
+
+				Assert.That(queryResult[0].Rate, Is.EqualTo(_testRate));
+				await (t.CommitAsync());
+			}
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/NH3787/Mappings.hbm.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="NHibernate.Test"
+                   namespace="NHibernate.Test.NHSpecificTest.NH3787">
+  <class name="TestEntity" table="TestEntity">
+    <id name="Id">
+      <generator class="native"/>
+    </id>
+    <property name="UsePreviousRate" type="boolean" not-null="true"/>
+    <property name="PreviousRate" type="decimal(18,13)" not-null="true"/>
+    <property name="Rate" type="decimal(18,13)" not-null="true"/>
+  </class>
+</hibernate-mapping>

src/NHibernate.Test/NHSpecificTest/NH3787/RateDto.cs

@@ -0,0 +1,7 @@
+namespace NHibernate.Test.NHSpecificTest.NH3787
+{
+    public class RateDto
+    {
+        public decimal Rate { get; set; }
+    }
+}

src/NHibernate.Test/NHSpecificTest/NH3787/TestEntity.cs

@@ -0,0 +1,10 @@
+namespace NHibernate.Test.NHSpecificTest.NH3787
+{
+    public class TestEntity
+    {
+        public virtual int Id { get; set; }
+        public virtual bool UsePreviousRate { get; set; }
+        public virtual decimal Rate { get; set; }
+        public virtual decimal PreviousRate { get; set; }
+    }
+}

src/NHibernate.Test/NHSpecificTest/NH3787/TestFixture.cs

@@ -0,0 +1,129 @@
+using System.Linq;
+using NHibernate.Criterion;
+using NHibernate.Linq;
+using NHibernate.Transform;
+using NHibernate.Type;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.NH3787
+{
+	[TestFixture]
+	public class TestFixture : BugTestCase
+	{
+		private const decimal _testRate = 12345.1234567890123M;
+
+		protected override bool AppliesTo(Dialect.Dialect dialect)
+		{
+			return !TestDialect.HasBrokenDecimalType;
+		}
+
+		protected override void OnSetUp()
+		{
+			base.OnSetUp();
+
+			using (var s = OpenSession())
+			using (var t = s.BeginTransaction())
+			{
+				var testEntity = new TestEntity
+				{
+					UsePreviousRate = true,
+					PreviousRate = _testRate,
+					Rate = 54321.1234567890123M
+				};
+				s.Save(testEntity);
+				t.Commit();
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var s = OpenSession())
+			using (var t = s.BeginTransaction())
+			{
+				s.CreateQuery("delete from TestEntity").ExecuteUpdate();
+				t.Commit();
+			}
+		}
+
+		[Test]
+		public void TestLinqQuery()
+		{
+			using (var s = OpenSession())
+			using (var t = s.BeginTransaction())
+			{
+				var queryResult = s
+					.Query<TestEntity>()
+					.Where(e => e.PreviousRate == _testRate)
+					.ToList();
+
+				Assert.That(queryResult.Count, Is.EqualTo(1));
+				Assert.That(queryResult[0].PreviousRate, Is.EqualTo(_testRate));
+				t.Commit();
+			}
+		}
+
+		[Test]
+		public void TestLinqProjection()
+		{
+			using (var s = OpenSession())
+			using (var t = s.BeginTransaction())
+			{
+				var queryResult = (from test in s.Query<TestEntity>()
+				                   select new RateDto { Rate = test.UsePreviousRate ? test.PreviousRate : test.Rate }).ToList();
+
+				// Check it has not been truncated to the default scale (10) of NHibernate.
+				Assert.That(queryResult[0].Rate, Is.EqualTo(_testRate));
+				t.Commit();
+			}
+		}
+
+		[Test]
+		public void TestLinqQueryOnExpression()
+		{
+			using (var s = OpenSession())
+			using (var t = s.BeginTransaction())
+			{
+				var queryResult = s
+					.Query<TestEntity>()
+					.Where(
+						// Without MappedAs, the test fails for SQL Server because it would restrict its parameter to the dialect's default scale.
+						e => (e.UsePreviousRate ? e.PreviousRate : e.Rate) == _testRate.MappedAs(TypeFactory.Basic("decimal(18,13)")))
+					.ToList();
+
+				Assert.That(queryResult.Count, Is.EqualTo(1));
+				Assert.That(queryResult[0].PreviousRate, Is.EqualTo(_testRate));
+				t.Commit();
+			}
+		}
+
+		[Test]
+		public void TestQueryOverProjection()
+		{
+			using (var s = OpenSession())
+			using (var t = s.BeginTransaction())
+			{
+				TestEntity testEntity = null;
+
+				var rateDto = new RateDto();
+				//Generated sql
+				//exec sp_executesql N'SELECT (case when this_.UsePreviousRate = @p0 then this_.PreviousRate else this_.Rate end) as y0_ FROM [TestEntity] this_',N'@p0 bit',@p0=1
+				var query = s
+					.QueryOver(() => testEntity)
+					.Select(
+						Projections
+							.Alias(
+								Projections.Conditional(
+									Restrictions.Eq(Projections.Property(() => testEntity.UsePreviousRate), true),
+									Projections.Property(() => testEntity.PreviousRate),
+									Projections.Property(() => testEntity.Rate)),
+								"Rate")
+							.WithAlias(() => rateDto.Rate));
+
+				var queryResult = query.TransformUsing(Transformers.AliasToBean<RateDto>()).List<RateDto>();
+
+				Assert.That(queryResult[0].Rate, Is.EqualTo(_testRate));
+				t.Commit();
+			}
+		}
+	}
+}

src/NHibernate/Dialect/Dialect.cs

@@ -98,6 +98,7 @@ protected Dialect()
 			RegisterFunction("upper", new StandardSQLFunction("upper"));
 			RegisterFunction("lower", new StandardSQLFunction("lower"));
 			RegisterFunction("cast", new CastFunction());
+			RegisterFunction("transparentcast", new TransparentCastFunction());
 			RegisterFunction("extract", new AnsiExtractFunction());
 			RegisterFunction("concat", new VarArgsSQLFunction(NHibernateUtil.String, "(", "||", ")"));
 

src/NHibernate/Dialect/Function/TransparentCastFunction.cs

@@ -0,0 +1,16 @@
+using System;
+
+namespace NHibernate.Dialect.Function
+{
+	/// <summary>
+	/// A HQL only cast for helping HQL knowing the type. Does not generates any actual cast in SQL code.
+	/// </summary>
+	[Serializable]
+	public class TransparentCastFunction : CastFunction
+	{
+		protected override bool CastingIsRequired(string sqlType)
+		{
+			return false;
+		}
+	}
+}

src/NHibernate/Dialect/SQLiteDialect.cs

@@ -86,6 +86,9 @@ protected virtual void RegisterFunctions()
 			RegisterFunction("cast", new SQLiteCastFunction());
 
 			RegisterFunction("round", new StandardSQLFunction("round"));
+
+			// NH-3787: SQLite requires the cast in SQL too for not defaulting to string.
+			RegisterFunction("transparentcast", new CastFunction());
 		}
 
 		#region private static readonly string[] DialectKeywords = { ... }

src/NHibernate/Hql/Ast/ANTLR/SessionFactoryHelperExtensions.cs

@@ -77,7 +77,7 @@ public IType FindFunctionReturnType(String functionName, IASTNode first)
 
 			if (first != null)
 			{
-				if (functionName == "cast")
+				if (sqlFunction is CastFunction)
 				{
 					argumentType = TypeFactory.HeuristicType(first.NextSibling.Text);
 				}

src/NHibernate/Hql/Ast/HqlTreeBuilder.cs

@@ -301,6 +301,17 @@ public HqlCast Cast(HqlExpression expression, System.Type type)
 			return new HqlCast(_factory, expression, type);
 		}
 
+		/// <summary>
+		/// Generate a cast node intended solely to hint HQL at the resulting type, without issuing an actual SQL cast.
+		/// </summary>
+		/// <param name="expression">The expression to cast.</param>
+		/// <param name="type">The resulting type.</param>
+		/// <returns>A <see cref="HqlTransparentCast"/> node.</returns>
+		public HqlTransparentCast TransparentCast(HqlExpression expression, System.Type type)
+		{
+			return new HqlTransparentCast(_factory, expression, type);
+		}
+
 		public HqlBitwiseNot BitwiseNot()
 		{
 			return new HqlBitwiseNot(_factory);

src/NHibernate/Hql/Ast/HqlTreeNode.cs

@@ -701,6 +701,19 @@ public HqlCast(IASTFactory factory, HqlExpression expression, System.Type type)
 		}
 	}
 
+	/// <summary>
+	/// Cast node intended solely to hint HQL at the resulting type, without issuing an actual SQL cast.
+	/// </summary>
+	public class HqlTransparentCast : HqlExpression
+	{
+		public HqlTransparentCast(IASTFactory factory, HqlExpression expression, System.Type type)
+			: base(HqlSqlWalker.METHOD_CALL, "method", factory)
+		{
+			AddChild(new HqlIdent(factory, "transparentcast"));
+			AddChild(new HqlExpressionList(factory, expression, new HqlIdent(factory, type)));
+		}
+	}
+
 	public class HqlCoalesce : HqlExpression
 	{
 		public HqlCoalesce(IASTFactory factory, HqlExpression lhs, HqlExpression rhs)