DapperExtensions GetById 不返回 object

Question

I'm using DapperExtensions and the framework I'm using is .NET-Core.

I have a base repository with the following:

public T GetById(int id)
{
   using (SqlConnection sqlConnection = new SqlConnection(_dbConnection.ConnectionString))
   {
      return sqlConnection.Get<T>(id);
   }
}

I'm calling this method like so:

var skip = _skipRepository.GetById(id);

In my table I only have 3 records and as you can see I'm trying to grab a Skip by Id

Here is my domain object:

public class Skip
{
    [Key]
    public int Id { get; set; }

    public string Name { get; set; }

    public string Description { get; set; }

    public decimal BasePrice { get; set; }

    public decimal PricePerDayAfter14Days { get; set; }

    public int Quantity { get; set; }
}

For some reason, the GetById throws an exception indicating that it expects 1 element but has got 3 elements.

My database table has 3 records and so I started to dig deeper and run a SQL Profiler to what I found this query:

SELECT [y_1].[Id] AS [c_0], [y_1].[Name] AS [c_1], [y_1].[Description] AS [c_2], [y_1].[BasePrice] AS [c_3], [y_1].[PricePerDayAfter14Days] AS [c_4], [y_1].[Quantity] AS [c_5] FROM [Skip] [y_1]

As you can see its not added a Where clause and I'm struggling to understand why.

Does anyone know what I'm doing wrong?

Answer 1

You are mapping the primary key using [Key] attribute. This mapping does not work with Dapper Extensions. You need to map something like below:

public sealed class ProductMapper : ClassMapper<Product>
{
    public ProductMapper()
    {
        Schema("dbo");
        Table("Products");
        Map(x => x.Id).Key(KeyType.Guid);
        AutoMap();
    }
}

You also need to call SetMappingAssemblies at the startup of the project to apply these mappings.

Please refer to this answer to learn more about mappings in Dapper Extensions.