Add a driver to support Microsoft.Data.SqlClient provider

src/NHibernate/Driver/MicrosoftDataSqlClientDriver.cs

@@ -0,0 +1,201 @@
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.Data.Common;
+using NHibernate.AdoNet;
+using NHibernate.Dialect;
+using NHibernate.Engine;
+using NHibernate.SqlTypes;
+
+namespace NHibernate.Driver
+{
+	/// <summary>
+	///     A NHibernate Driver for using the SqlClient DataProvider
+	/// </summary>
+	public class MicrosoftDataSqlClientDriver : ReflectionBasedDriver, IEmbeddedBatcherFactoryProvider, IParameterAdjuster
+	{
+		private Dialect.Dialect _dialect;
+
+		public MicrosoftDataSqlClientDriver()
+			: base(
+				"Microsoft.Data.SqlClient",
+				"Microsoft.Data.SqlClient.SqlConnection",
+				"Microsoft.Data.SqlClient.SqlCommand")
+		{
+		}
+
+		/// <summary>
+		///     MsSql requires the use of a Named Prefix in the SQL statement.
+		/// </summary>
+		/// <remarks>
+		///     <see langword="true" /> because MsSql uses "<c>@</c>".
+		/// </remarks>
+		public override bool UseNamedPrefixInSql => true;
+
+		/// <summary>
+		///     MsSql requires the use of a Named Prefix in the Parameter.
+		/// </summary>
+		/// <remarks>
+		///     <see langword="true" /> because MsSql uses "<c>@</c>".
+		/// </remarks>
+		public override bool UseNamedPrefixInParameter => true;
+
+		/// <summary>
+		///     The Named Prefix for parameters.
+		/// </summary>
+		/// <value>
+		///     Sql Server uses <c>"@"</c>.
+		/// </value>
+		public override string NamedPrefix => "@";
+
+		/// <summary>
+		///     The SqlClient driver does NOT support more than 1 open DbDataReader
+		///     with only 1 DbConnection.
+		/// </summary>
+		/// <value><see langword="false" /> - it is not supported.</value>
+		/// <remarks>
+		///     MS SQL Server 2000 (and 7) throws an exception when multiple DbDataReaders are
+		///     attempted to be opened.  When SQL Server 2005 comes out a new driver will be
+		///     created for it because SQL Server 2005 is supposed to support it.
+		/// </remarks>
+		public override bool SupportsMultipleOpenReaders => false;
+
+		/// <inheritdoc />
+		public override bool SupportsMultipleQueries => true;
+
+		/// <summary>
+		///     With read committed snapshot or lower, SQL Server may have not actually already committed the transaction
+		///     right after the scope disposal.
+		/// </summary>
+		public override bool HasDelayedDistributedTransactionCompletion => true;
+
+		/// <inheritdoc />
+		public override DateTime MinDate => new DateTime(1753, 1, 1);
+
+		System.Type IEmbeddedBatcherFactoryProvider.BatcherFactoryClass => typeof(GenericBatchingBatcherFactory);
+
+		/// <inheritdoc />
+		public virtual void AdjustParameterForValue(DbParameter parameter, SqlType sqlType, object value)
+		{
+			if (value is string stringVal)
+				switch (parameter.DbType)
+				{
+					case DbType.AnsiString:
+					case DbType.AnsiStringFixedLength:
+						parameter.Size = IsAnsiText(parameter, sqlType)
+							? MsSql2000Dialect.MaxSizeForAnsiClob
+							: Math.Max(stringVal.Length, sqlType.LengthDefined ? sqlType.Length : parameter.Size);
+						break;
+					case DbType.String:
+					case DbType.StringFixedLength:
+						parameter.Size = IsText(parameter, sqlType)
+							? MsSql2000Dialect.MaxSizeForClob
+							: Math.Max(stringVal.Length, sqlType.LengthDefined ? sqlType.Length : parameter.Size);
+						break;
+				}
+		}
+
+		public override void Configure(IDictionary<string, string> settings)
+		{
+			base.Configure(settings);
+
+			_dialect = Dialect.Dialect.GetDialect(settings);
+		}
+
+		/// <inheritdoc />
+		protected override void InitializeParameter(DbParameter dbParam, string name, SqlType sqlType)
+		{
+			base.InitializeParameter(dbParam, name, sqlType);
+
+			// Defaults size/precision/scale
+			switch (dbParam.DbType)
+			{
+				case DbType.AnsiString:
+				case DbType.AnsiStringFixedLength:
+					dbParam.Size = IsAnsiText(dbParam, sqlType)
+						? MsSql2000Dialect.MaxSizeForAnsiClob
+						: MsSql2000Dialect.MaxSizeForLengthLimitedAnsiString;
+					break;
+				case DbType.Binary:
+					dbParam.Size = IsBlob(dbParam, sqlType)
+						? MsSql2000Dialect.MaxSizeForBlob
+						: MsSql2000Dialect.MaxSizeForLengthLimitedBinary;
+					break;
+				case DbType.Decimal:
+					if (_dialect == null)
+						throw new InvalidOperationException(
+							"Dialect not available, is this driver used without having been configured?");
+					dbParam.Precision = _dialect.DefaultCastPrecision;
+					dbParam.Scale = _dialect.DefaultCastScale;
+					break;
+				case DbType.String:
+				case DbType.StringFixedLength:
+					dbParam.Size = IsText(dbParam, sqlType)
+						? MsSql2000Dialect.MaxSizeForClob
+						: MsSql2000Dialect.MaxSizeForLengthLimitedString;
+					break;
+				case DbType.DateTime2:
+					dbParam.Size = MsSql2000Dialect.MaxDateTime2;
+					break;
+				case DbType.DateTimeOffset:
+					dbParam.Size = MsSql2000Dialect.MaxDateTimeOffset;
+					break;
+				case DbType.Xml:
+					dbParam.Size = MsSql2005Dialect.MaxSizeForXml;
+					break;
+			}
+
+			// Do not override the default length for string using data from SqlType, since LIKE expressions needs
+			// larger columns. https://nhibernate.jira.com/browse/NH-3036
+
+			if (sqlType.PrecisionDefined)
+			{
+				dbParam.Precision = sqlType.Precision;
+				dbParam.Scale = sqlType.Scale;
+			}
+		}
+
+		/// <summary>
+		///     Interprets if a parameter is a Clob (for the purposes of setting its default size)
+		/// </summary>
+		/// <param name="dbParam">The parameter</param>
+		/// <param name="sqlType">The <see cref="SqlType" /> of the parameter</param>
+		/// <returns>True, if the parameter should be interpreted as a Clob, otherwise False</returns>
+		protected static bool IsAnsiText(DbParameter dbParam, SqlType sqlType)
+		{
+			return (DbType.AnsiString == dbParam.DbType || DbType.AnsiStringFixedLength == dbParam.DbType) &&
+			       sqlType.LengthDefined && sqlType.Length > MsSql2000Dialect.MaxSizeForLengthLimitedAnsiString;
+		}
+
+		/// <summary>
+		///     Interprets if a parameter is a Clob (for the purposes of setting its default size)
+		/// </summary>
+		/// <param name="dbParam">The parameter</param>
+		/// <param name="sqlType">The <see cref="SqlType" /> of the parameter</param>
+		/// <returns>True, if the parameter should be interpreted as a Clob, otherwise False</returns>
+		protected static bool IsText(DbParameter dbParam, SqlType sqlType)
+		{
+			return sqlType is StringClobSqlType ||
+			       (DbType.String == dbParam.DbType || DbType.StringFixedLength == dbParam.DbType) &&
+			       sqlType.LengthDefined && sqlType.Length > MsSql2000Dialect.MaxSizeForLengthLimitedString;
+		}
+
+		/// <summary>
+		///     Interprets if a parameter is a Blob (for the purposes of setting its default size)
+		/// </summary>
+		/// <param name="dbParam">The parameter</param>
+		/// <param name="sqlType">The <see cref="SqlType" /> of the parameter</param>
+		/// <returns>True, if the parameter should be interpreted as a Blob, otherwise False</returns>
+		protected static bool IsBlob(DbParameter dbParam, SqlType sqlType)
+		{
+			return sqlType is BinaryBlobSqlType || DbType.Binary == dbParam.DbType && sqlType.LengthDefined &&
+			       sqlType.Length > MsSql2000Dialect.MaxSizeForLengthLimitedBinary;
+		}
+
+		/// <inheritdoc />
+		public override IResultSetsCommand GetResultSetsCommand(ISessionImplementor session)
+		{
+			return new BasicResultSetsCommand(session);
+		}
+	}
+}