如何云化两个通用参数,一个用于规范,一个用于类型推断

public static class MiniSQLHelper{
    public static object SqlQuerySingleOrDefault<TParam>(this IDbConnection cnn, string query, TParam param)
        where TParam : class 
    {
        //......
    }    
}

using (var conn = Connection){
    var result = conn.SqlQuerySingleOrDefault("select @v ", new { v = 1 }); /*Success*/
}

泛型类返回类型错误

public static class MiniSQLHelper{
    public static T SqlQuerySingleOrDefault<T, TParam>(this IDbConnection cnn, string query, TParam param)
        where TParam : class 
    {
        //......
    }    
}

using (var conn = Connection){
    var result = conn.SqlQuerySingleOrDefault<int>("select @v ", new { v = 1 });/*CS1503 C# Argument 3: cannot convert from to 'int'*/
}

问题

Online Test Demo| .NET Fiddle