Add support for Oracle binary floating point types (#2349)

Author: maca88

src/NHibernate.Test/Async/Linq/ByMethod/AverageTests.cs

@@ -22,6 +22,7 @@ public class AverageTestsAsync : LinqTestCase
 		[Test]
 		public async Task CanGetAverageOfIntegersAsDoubleAsync()
 		{
+			// TODO 6.0: Enable test for Oracle once nhibernate.oracle.use_binary_floating_point_types is set to true
 			if (Dialect is Oracle8iDialect)
 			{
 				// The point of this test is to verify that LINQ's Average over an
@@ -50,4 +51,4 @@ public async Task CanGetAverageOfIntegersAsDoubleAsync()
 			Assert.AreEqual(average, 10.129870d, 0.000001d);
 		}
 	}
-}
+}

src/NHibernate.Test/DriverTest/OracleClientDriverFixture.cs

@@ -9,6 +9,8 @@ namespace NHibernate.Test.DriverTest
 	/// Summary description for OracleClientDriverFixture.
 	/// </summary>
 	[TestFixture]
+	// Since v5.3
+	[Obsolete]
 	public class OracleClientDriverFixture
 	{
 		/// <summary>
@@ -35,4 +37,4 @@ public void CommandClassName()
 			Assert.AreEqual("System.Data.OracleClient.OracleCommand", cmd.GetType().FullName);
 		}
 	}
-}
+}

src/NHibernate.Test/Linq/ByMethod/AverageTests.cs

@@ -10,6 +10,7 @@ public class AverageTests : LinqTestCase
 		[Test]
 		public void CanGetAverageOfIntegersAsDouble()
 		{
+			// TODO 6.0: Enable test for Oracle once nhibernate.oracle.use_binary_floating_point_types is set to true
 			if (Dialect is Oracle8iDialect)
 			{
 				// The point of this test is to verify that LINQ's Average over an
@@ -38,4 +39,4 @@ public void CanGetAverageOfIntegersAsDouble()
 			Assert.AreEqual(average, 10.129870d, 0.000001d);
 		}
 	}
-}
+}

src/NHibernate/Cfg/Environment.cs

@@ -319,6 +319,20 @@ public static string Version
 		/// </remarks>
 		public const string OracleUseNPrefixedTypesForUnicode = "oracle.use_n_prefixed_types_for_unicode";
 
+		/// <summary>
+		/// Oracle 10g introduced BINARY_DOUBLE and BINARY_FLOAT types which are compatible with .NET
+		/// <see cref="double"/> and <see cref="float"/> types, where FLOAT and DOUBLE are not. Oracle
+		/// FLOAT and DOUBLE types do not conform to the IEEE standard as they are internally implemented as
+		/// NUMBER type, which makes them an exact numeric type.
+		/// <para>
+		/// <see langword="false"/> by default.
+		/// </para>
+		/// </summary>
+		/// <remarks>
+		/// See https://docs.oracle.com/database/121/TTSQL/types.htm#TTSQL126
+		/// </remarks>
+		public const string OracleUseBinaryFloatingPointTypes = "oracle.use_binary_floating_point_types";
+
 		/// <summary>
 		/// <para>
 		/// Firebird with FirebirdSql.Data.FirebirdClient may be unable to determine the type

src/NHibernate/Dialect/Oracle10gDialect.cs

@@ -1,5 +1,10 @@
+using System.Collections.Generic;
+using System.Data;
+using NHibernate.Cfg;
 using NHibernate.Dialect.Function;
 using NHibernate.SqlCommand;
+using NHibernate.SqlTypes;
+using NHibernate.Util;
 
 namespace NHibernate.Dialect
 {
@@ -12,11 +17,41 @@ namespace NHibernate.Dialect
 	/// </remarks>
 	public class Oracle10gDialect : Oracle9iDialect
 	{
+		private bool _useBinaryFloatingPointTypes;
+
 		public override JoinFragment CreateOuterJoinFragment()
 		{
 			return new ANSIJoinFragment();
 		}
 
+		public override void Configure(IDictionary<string, string> settings)
+		{
+			base.Configure(settings);
+
+			_useBinaryFloatingPointTypes = PropertiesHelper.GetBoolean(
+				Environment.OracleUseBinaryFloatingPointTypes,
+				settings,
+				false);
+		}
+
+		// Avoid registering weighted double type when using binary floating point types
+		protected override void RegisterFloatingPointTypeMappings()
+		{
+			if (_useBinaryFloatingPointTypes)
+			{
+				// Use binary_float (available since 10g) instead of float. With Oracle, float is a decimal but
+				// with a precision expressed in number of bytes instead of digits.
+				RegisterColumnType(DbType.Single, "binary_float");
+				// Using binary_double (available since 10g) instead of double precision. With Oracle, double
+				// precision is a float(126), which is a decimal with a 126 bytes precision.
+				RegisterColumnType(DbType.Double, "binary_double");
+			}
+			else
+			{
+				base.RegisterFloatingPointTypeMappings();
+			}
+		}
+
 		protected override void RegisterFunctions()
 		{
 			base.RegisterFunctions();
@@ -29,19 +64,6 @@ protected override void RegisterFunctions()
 			RegisterFunction("random", new SQLFunctionTemplate(NHibernateUtil.Double, "cast(DBMS_RANDOM.VALUE() as binary_double)"));
 		}
 
-		/* 6.0 TODO: consider redefining float and double registrations
-		protected override void RegisterNumericTypeMappings()
-		{
-			base.RegisterNumericTypeMappings();
-
-			// Use binary_float (available since 10g) instead of float. With Oracle, float is a decimal but
-			// with a precision expressed in number of bytes instead of digits.
-			RegisterColumnType(DbType.Single, "binary_float");
-			// Using binary_double (available since 10g) instead of double precision. With Oracle, double
-			// precision is a float(126), which is a decimal with a 126 bytes precision.
-			RegisterColumnType(DbType.Double, "binary_double");
-		}*/
-
 		/// <inheritdoc />
 		public override bool SupportsCrossJoin => true;
 	}

src/NHibernate/Dialect/Oracle8iDialect.cs

@@ -102,6 +102,7 @@ public override void Configure(IDictionary<string, string> settings)
 			// If changing the default value, keep it in sync with OracleDataClientDriverBase.Configure.
 			UseNPrefixedTypesForUnicode = PropertiesHelper.GetBoolean(Environment.OracleUseNPrefixedTypesForUnicode, settings, false);
 			RegisterCharacterTypeMappings();
+			RegisterFloatingPointTypeMappings();
 		}
 
 		#region private static readonly string[] DialectKeywords = { ... }
@@ -184,14 +185,18 @@ protected virtual void RegisterNumericTypeMappings()
 
 			// 6.0 TODO: bring down to 18,4 for consistency with other dialects.
 			RegisterColumnType(DbType.Currency, "NUMBER(22,4)");
-			RegisterColumnType(DbType.Single, "FLOAT(24)");
-			RegisterColumnType(DbType.Double, "DOUBLE PRECISION");
-			RegisterColumnType(DbType.Double, 40, "NUMBER($p,$s)");
 			RegisterColumnType(DbType.Decimal, "NUMBER(19,5)");
 			// Oracle max precision is 39-40, but .Net is limited to 28-29.
 			RegisterColumnType(DbType.Decimal, 29, "NUMBER($p,$s)");
 		}
 
+		protected virtual void RegisterFloatingPointTypeMappings()
+		{
+			RegisterColumnType(DbType.Single, "FLOAT(24)");
+			RegisterColumnType(DbType.Double, "DOUBLE PRECISION");
+			RegisterColumnType(DbType.Double, 40, "NUMBER($p,$s)");
+		}
+
 		protected virtual void RegisterDateTimeTypeMappings()
 		{
 			RegisterColumnType(DbType.Date, "DATE");

src/NHibernate/Driver/OracleClientDriver.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Data;
 using System.Data.Common;
 using NHibernate.Engine.Query;
@@ -8,6 +9,9 @@ namespace NHibernate.Driver
 	/// <summary>
 	/// A NHibernate Driver for using the Oracle DataProvider.
 	/// </summary>
+	// Since v5.3
+	// Deprecated by Microsoft: https://docs.microsoft.com/en-us/dotnet/framework/data/adonet/oracle-and-adonet
+	[Obsolete("Use OracleManagedDataClientDriver or OracleDataClientDriver driver instead.")]
 	public class OracleClientDriver : ReflectionBasedDriver
 	{
 		private static readonly SqlType GuidSqlType = new SqlType(DbType.Binary, 16);

src/NHibernate/Driver/OracleDataClientDriverBase.cs

@@ -30,6 +30,8 @@ public abstract class OracleDataClientDriverBase : ReflectionBasedDriver, IEmbed
 		private readonly object _oracleDbTypeBlob;
 		private readonly object _oracleDbTypeNVarchar2;
 		private readonly object _oracleDbTypeNChar;
+		private readonly object _oracleDbTypeBinaryDouble;
+		private readonly object _oracleDbTypeBinaryFloat;
 
 		/// <summary>
 		/// Default constructor.
@@ -58,6 +60,8 @@ private OracleDataClientDriverBase(string driverAssemblyName, string clientNames
 			_oracleDbTypeBlob = Enum.Parse(oracleDbTypeEnum, "Blob");
 			_oracleDbTypeNVarchar2 = Enum.Parse(oracleDbTypeEnum, "NVarchar2");
 			_oracleDbTypeNChar = Enum.Parse(oracleDbTypeEnum, "NChar");
+			_oracleDbTypeBinaryDouble = Enum.Parse(oracleDbTypeEnum, "BinaryDouble");
+			_oracleDbTypeBinaryFloat = Enum.Parse(oracleDbTypeEnum, "BinaryFloat");
 		}
 
 		/// <inheritdoc/>
@@ -67,6 +71,7 @@ public override void Configure(IDictionary<string, string> settings)
 
 			// If changing the default value, keep it in sync with Oracle8iDialect.Configure.
 			UseNPrefixedTypesForUnicode = PropertiesHelper.GetBoolean(Cfg.Environment.OracleUseNPrefixedTypesForUnicode, settings, false);
+			UseBinaryFloatingPointTypes = PropertiesHelper.GetBoolean(Cfg.Environment.OracleUseBinaryFloatingPointTypes, settings, false);
 		}
 
 		/// <summary>
@@ -84,6 +89,11 @@ public override void Configure(IDictionary<string, string> settings)
 		/// </remarks>
 		public bool UseNPrefixedTypesForUnicode { get; private set; }
 
+		/// <summary>
+		/// Whether binary_double and binary_float are used for <see cref="double"/> and <see cref="float"/> types.
+		/// </summary>
+		public bool UseBinaryFloatingPointTypes { get; private set; }
+
 		/// <inheritdoc/>
 		public override bool UseNamedPrefixInSql => true;
 
@@ -131,6 +141,18 @@ protected override void InitializeParameter(DbParameter dbParam, string name, Sq
 				case DbType.Currency:
 					base.InitializeParameter(dbParam, name, SqlTypeFactory.Decimal);
 					break;
+				case DbType.Double:
+					if (UseBinaryFloatingPointTypes)
+						InitializeParameter(dbParam, name, _oracleDbTypeBinaryDouble);
+					else
+						base.InitializeParameter(dbParam, name, sqlType);
+					break;
+				case DbType.Single:
+					if (UseBinaryFloatingPointTypes)
+						InitializeParameter(dbParam, name, _oracleDbTypeBinaryFloat);
+					else
+						base.InitializeParameter(dbParam, name, sqlType);
+					break;
 				default:
 					base.InitializeParameter(dbParam, name, sqlType);
 					break;

src/NHibernate/nhibernate-configuration.xsd

@@ -240,6 +240,18 @@
 												</xs:documentation>
 											</xs:annotation>
 										</xs:enumeration>
+										<xs:enumeration value="oracle.use_binary_floating_point_types">
+											<xs:annotation>
+												<xs:documentation>
+													Oracle 10g introduced BINARY_DOUBLE and BINARY_FLOAT types which are compatible with .NET
+													double and float types, where FLOAT and DOUBLE are not. Oracle FLOAT and DOUBLE types do
+													not conform to the IEEE standard as they are internally implemented as NUMBER type, which
+													makes them an exact numeric type.
+													False by default.
+													See https://docs.oracle.com/database/121/TTSQL/types.htm#TTSQL126
+												</xs:documentation>
+											</xs:annotation>
+										</xs:enumeration>
 										<xs:enumeration value="firebird.disable_parameter_casting">
 											<xs:annotation>
 												<xs:documentation>