MySQL 执行原生sql

public class MySqlHelper
{
    private YourContext _context;

    public MySqlHelper(YourContext context)
    {
        _context = context;
    }

    /// <summary>
    /// 查询列表
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="sql"></param>
    /// <returns></returns>
    public List<T> QueryForDatable<T>(string sql)
    {
        string conn= _context.Database.Connection.ConnectionString;
        using(var connection= new MySqlConnection(conn))
        {
            MySqlCommand cmd = new MySqlCommand(sql, connection);
            //需要open才能执行Command
            connection.Open();
            using (MySqlDataReader reader = cmd.ExecuteReader())
            {
                List<T> data = DataReaderMapToList<T>(reader);
                connection.Close();
                return data;
            }
        }
    }

    /// <summary>
    /// 查询数量
    /// </summary>
    /// <param name="sql"></param>
    /// <returns></returns>
    public int QueryForCount(string sql)
    {
        string conn = _context.Database.Connection.ConnectionString;
        using (var connection = new MySqlConnection(conn))
        {
            MySqlCommand cmd = new MySqlCommand(sql, connection);
            connection.Open();
            //只取第一行第一个结果
            Object result = cmd.ExecuteScalar();
            if (result != null)
            {
                int count = int.Parse(result.ToString());
                connection.Close();
                return count;
            }
            connection.Close();
            return 0;
        }
    }

    public static List<T> DataReaderMapToList<T>(IDataReader dr)
    {
        List<T> list = new List<T>();
        T obj = default(T);
        List<string> columnNames = new List<string>();
        //查询DataReader里面的列名集合
        for (var f = 0; f < dr.FieldCount; f++)
        {
            columnNames.Add(dr.GetName(f));
        }
        while (dr.Read())
        {
            obj = Activator.CreateInstance<T>();
            foreach (PropertyInfo prop in obj.GetType().GetProperties())
            {
                //判断列名是否存在
                var columnName = columnNames.Find(x => x == prop.Name);
                if (!string.IsNullOrEmpty(columnName))
                {
                    prop.SetValue(obj, dr[prop.Name]);
                }
            }
            list.Add(obj);
        }
        return list;
    }
}