Dapper QueryAsync，返回一个列表

Question

I have this task in C# with which i want to call a stored procedure in MySql using dapper.

public async Task<List<StatItemListViewModel>> GetTable()
    {
        using (MySqlConnection connection = new MySqlConnection(Helper.CnnVal("SampleDB")))
        {
            var results =await connection.QueryAsync<List<StatItemListViewModel>>("Call MainResult_Statistic(@sDate, @eDate)", new { sDate = "2018-11-01", eDate = "2018-11-30" });

            return results.FirstOrDefault();
        }            
    }

The problem is that it doesn't return anything.

Can someone help me please?

Answer 1

I solved the issue like this:

public async Task<IEnumerable<StatItemListViewModel>> GetTable(string sDate, string eDate)
{
    using (MySqlConnection connection = new MySqlConnection(Helper.CnnVal("SampleDB")))
    {
        var results = await connection.QueryAsync<StatItemListViewModel>("Call MainResult_Statistic(@sDate, @eDate)", 
            new { sDate, eDate });

        return results.ToList();
    }                  
}

The problem was that I could not convert generic.Ienumerable to generic.List.

Answer 2

public virtual async Task<T> QueryFirstAsync<T>(string strSql, object param)
{
    using (IDbConnection conn = Connection)
    {
        var res = await conn.QueryAsync<T>(strSql, param);
        return res.FirstOrDefault<T>();
    }
}