NH-3109 - Fix rounding numeric types in cast expressions for MySQL5Dialect

Author: hazzik

src/NHibernate/Dialect/MySQL5Dialect.cs

@@ -15,10 +15,12 @@ public MySQL5Dialect()
 		protected override void RegisterCastTypes() {
 			base.RegisterCastTypes();
 			// MySql 5 also supports DECIMAL as a cast type target
-			// http://dev.mysql.com/doc/refman/5.5/en/cast-functions.html
-			RegisterCastType(DbType.Decimal, "DECIMAL");
-			RegisterCastType(DbType.Double, "DECIMAL");
-			RegisterCastType(DbType.Single, "DECIMAL");
+			// http://dev.mysql.com/doc/refman/5.0/en/cast-functions.html
+			RegisterCastType(DbType.Decimal, "DECIMAL(19,5)");
+			RegisterCastType(DbType.Decimal, 19, "DECIMAL($p, $s)");
+			RegisterCastType(DbType.Double, "DECIMAL(19,5)");
+			RegisterCastType(DbType.Single, "DECIMAL(19,5)");
+			RegisterCastType(DbType.Guid, "BINARY(16)");
 		}
 
 		//Reference 5.x

src/NHibernate/Dialect/MySQLDialect.cs

@@ -3,7 +3,8 @@
 using System.Data.Common;
 using System.Text;
 using NHibernate.Dialect.Function;
-using NHibernate.Dialect.Schema;
+using NHibernate.Dialect.Schema;
+using NHibernate.Mapping;
 using NHibernate.SqlCommand;
 using NHibernate.SqlTypes;
 using NHibernate.Util;
@@ -272,15 +273,27 @@ protected virtual void RegisterCastTypes()
 		}
 
 		/// <summary>
-		/// Suclasses register a typename for the given type code, to be used in CAST()
+		/// Subclasses register a typename for the given type code, to be used in CAST()
 		/// statements.
 		/// </summary>
 		/// <param name="code">The typecode</param>
 		/// <param name="name">The database type name</param>
 		protected void RegisterCastType(DbType code, string name)
 		{
 			castTypeNames.Put(code, name);
-		}
+		}
+
+		/// <summary>
+		/// Subclasses register a typename for the given type code, to be used in CAST()
+		/// statements.
+		/// </summary>
+		/// <param name="code">The typecode</param>
+		/// <param name="capacity"></param>
+		/// <param name="name">The database type name</param>
+		protected void RegisterCastType(DbType code, int capacity, string name)
+		{
+			castTypeNames.Put(code, capacity, name);
+		}
 
 		/// <summary> 
 		/// Get the name of the database type appropriate for casting operations
@@ -289,8 +302,8 @@ protected void RegisterCastType(DbType code, string name)
 		/// <param name="sqlType">The <see cref="SqlType"/> typecode </param>
 		/// <returns> The database type name </returns>
 		public override string GetCastTypeName(SqlType sqlType)
-		{
-			string result = castTypeNames.Get(sqlType.DbType);
+		{
+			string result = castTypeNames.Get(sqlType.DbType, Column.DefaultLength, Column.DefaultPrecision, Column.DefaultScale);
 			if (result == null)
 			{
 				throw new HibernateException(string.Format("No CAST() type mapping for SqlType {0}", sqlType));