We are using Dapper in a large enterprise winform application. Currently, we are in the process of upgrading our project targets from VS 2013 / .NET 4.5.2 to VS 2015 / .NET 4.6.1.During testing, we found that our Dapper repositories were failing when running under VS 2015.
Specifically, we have unique requirements for handling Enums and have had to take a direct file reference to Dapper which allows us to remove the readonly modifier on the SqlMapper.enumParse field and provide our own implementation which was worked as expected for over a year now.
We've isolated the issue down to what we believe is a difference in the VS 2013 compiler and VS 2015 compiler. Running under VS 2013, there are no issues with providing our own implementation of SqlMapper.enumParse. Under VS 2015, we receive a DataException: "An unhandled exception of type 'System.Data.DataException' occurred..." and the error points to the parsing of the enum.
The following is the bare minimum to reproduce the issue:
- Set up a solution and target .NET v4.5 to 4.6.1
- Drop in the code that follows the end of this post.
- Use the latest Dapper code and remove the SqlMapper.enumParse readonly modifier.
Of Note:
- The sample code resets the SqlMapper.enumParse field with a different implementation than the native Dapper code which uses the standard .NET Enum.Parse method.
- The underlying SQL always returns the Product.ProductType as ProductType.Gmo; the implementation of SqlMapper.enumParse will always set the enum to ProductType.Organic.
- Running under VS 2013, the expected results are produced where the Product.ProductType enum will always be ProductType.Organic. Under VS 2015, an exception occurs.
I realize this is not a Dapper specific issue, but was hoping you could provide some guidance on why this is occuring with the VS 2015 compiler?
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using Dapper;
using DapperRoslyn;
namespace Dapper
{
static partial class SqlMapper
{
internal static void SetEnumParse()
{
Func<Type, string, bool, object> dapperEnum = ( type, value, flag ) => ToEnum( type, value );
enumParse = dapperEnum.Method;
}
private static object ToEnum( Type type, string value )
{
return ProductType.Organic;
}
}
}
namespace DapperRoslyn
{
class Program
{
const string ConnectionString = "Data Source=.;Initial Catalog=.;Integrated Security=True";
static void Main()
{
SqlMapper.SetEnumParse();
var repo = new ProductRepository( ConnectionString );
var products = repo.GetAll();
foreach( Product product in products )
{
Console.WriteLine( product );
}
Console.ReadLine();
}
}
public class ProductRepository
{
private readonly string _connectionString;
public ProductRepository( string connectionString )
{
_connectionString = connectionString;
}
public IEnumerable<Product> GetAll()
{
const string sql = @"
create table #Product(Name nvarchar(25) not null, ProductType nvarchar(25) not null)
insert into #Product(Name, ProductType)
values
('Banana', 'Gmo')
,('Orange', 'Gmo')
,('Pear', 'Gmo')
,('Apple', 'Gmo')
,('Strawberry', 'Gmo')
Select Name, ProductType from #Product
drop table #Product
";
using( var conn = new SqlConnection( _connectionString ) )
{
var results = conn.Query<Product>( sql, commandType: CommandType.Text );
return results.ToList();
}
}
}
public enum ProductType
{
Unknown = 0,
Gmo = 1,
Organic = 2,
}
public class Product
{
public string Name { get; set; }
public ProductType ProductType { get; set; }
public override string ToString()
{
return string.Format( "{0} {1}", Name, ProductType );
}
}
}
We are using Dapper in a large enterprise winform application. Currently, we are in the process of upgrading our project targets from VS 2013 / .NET 4.5.2 to VS 2015 / .NET 4.6.1.During testing, we found that our Dapper repositories were failing when running under VS 2015.
Specifically, we have unique requirements for handling Enums and have had to take a direct file reference to Dapper which allows us to remove the readonly modifier on the SqlMapper.enumParse field and provide our own implementation which was worked as expected for over a year now.
We've isolated the issue down to what we believe is a difference in the VS 2013 compiler and VS 2015 compiler. Running under VS 2013, there are no issues with providing our own implementation of SqlMapper.enumParse. Under VS 2015, we receive a DataException: "An unhandled exception of type 'System.Data.DataException' occurred..." and the error points to the parsing of the enum.
The following is the bare minimum to reproduce the issue:
Of Note:
I realize this is not a Dapper specific issue, but was hoping you could provide some guidance on why this is occuring with the VS 2015 compiler?