Added support for TimeSpan

Fix for issue #70
(http://code.google.com/p/dapper-dot-net/issues/detail?id=70) and also
related MS bug with DbType.Time
(https://connect.microsoft.com/VisualStudio/feedback/details/381934/sqlparameter-dbtype-dbtype-time-sets-the-parameter-to-sqldbtype-datetime-instead-of-sqldbtype-time).

Dapper/SqlMapper.cs

@@ -301,6 +301,7 @@ static SqlMapper()
             typeMap[typeof(Guid)] = DbType.Guid;
             typeMap[typeof(DateTime)] = DbType.DateTime;
             typeMap[typeof(DateTimeOffset)] = DbType.DateTimeOffset;
+            typeMap[typeof(TimeSpan)] = DbType.Time;
             typeMap[typeof(byte[])] = DbType.Binary;
             typeMap[typeof(byte?)] = DbType.Byte;
             typeMap[typeof(sbyte?)] = DbType.SByte;
@@ -318,6 +319,7 @@ static SqlMapper()
             typeMap[typeof(Guid?)] = DbType.Guid;
             typeMap[typeof(DateTime?)] = DbType.DateTime;
             typeMap[typeof(DateTimeOffset?)] = DbType.DateTimeOffset;
+            typeMap[typeof(TimeSpan?)] = DbType.Time;
             typeMap[typeof(Object)] = DbType.Object;
         }
 
@@ -1366,10 +1368,13 @@ private static IEnumerable<PropertyInfo> FilterParameters(IEnumerable<PropertyIn
                 il.Emit(OpCodes.Ldstr, prop.Name); // stack is now [parameters] [parameters] [parameter] [parameter] [name]
                 il.EmitCall(OpCodes.Callvirt, typeof(IDataParameter).GetProperty("ParameterName").GetSetMethod(), null);// stack is now [parameters] [parameters] [parameter]
 
-                il.Emit(OpCodes.Dup);// stack is now [parameters] [parameters] [parameter] [parameter]
-                EmitInt32(il, (int)dbType);// stack is now [parameters] [parameters] [parameter] [parameter] [db-type]
+                if(dbType != DbType.Time) // https://connect.microsoft.com/VisualStudio/feedback/details/381934/sqlparameter-dbtype-dbtype-time-sets-the-parameter-to-sqldbtype-datetime-instead-of-sqldbtype-time
+                {
+                    il.Emit(OpCodes.Dup);// stack is now [parameters] [parameters] [parameter] [parameter]
+                    EmitInt32(il, (int)dbType);// stack is now [parameters] [parameters] [parameter] [parameter] [db-type]
 
-                il.EmitCall(OpCodes.Callvirt, typeof(IDataParameter).GetProperty("DbType").GetSetMethod(), null);// stack is now [parameters] [parameters] [parameter]
+                    il.EmitCall(OpCodes.Callvirt, typeof(IDataParameter).GetProperty("DbType").GetSetMethod(), null);// stack is now [parameters] [parameters] [parameter]
+                }
 
                 il.Emit(OpCodes.Dup);// stack is now [parameters] [parameters] [parameter] [parameter]
                 EmitInt32(il, (int)ParameterDirection.Input);// stack is now [parameters] [parameters] [parameter] [parameter] [dir]

Tests/Tests.cs

@@ -194,6 +194,14 @@ public void TestBoolParam()
                 .IsFalse();
         }
 
+        // http://code.google.com/p/dapper-dot-net/issues/detail?id=70
+        // https://connect.microsoft.com/VisualStudio/feedback/details/381934/sqlparameter-dbtype-dbtype-time-sets-the-parameter-to-sqldbtype-datetime-instead-of-sqldbtype-time
+        public void TestTimeSpanParam()
+        {
+            connection.Query<TimeSpan>("select @ts", new { ts = TimeSpan.FromMinutes(42) }).First()
+                .IsEqualTo(TimeSpan.FromMinutes(42));
+        }
+
         public void TestStrings()
         {
             connection.Query<string>(@"select 'a' a union select 'b'")