Azure WebJob 到：从 SQL 创建 CSV 文件并通过电子邮件作为附件发送

Question

到目前为止，设法：

1. 通过 Visual Studio 创建 C# Azure WebJob 项目并将其发布到 Web 应用程序，即：
2. 连接到 Azure SQL 数据库并执行 SQL 查询（通过 SqlDataReader）
3. 将 SqlDataReader 结果添加到电子邮件正文中
4. 发送电子邮件

除了上述之外，在上述第 3 点和第 4 点之间的某处，我需要:

5. 创建 .CSV 文件
6. 从 SqlDataReader 填充 .CSV 文件
7. 通过电子邮件将 .CSV 文件作为附件发送

从 SqlDataReader 填充 CSV 的结果集如下所示：

asdasd@gmail.com ,11/19/2018
asdasdasd@gmail.com ,11/19/2018
asdasdasasdas@live.co.uk ,11/19/2018
asdasddsa@hotmail.com ,11/19/2018
asdasd@hotmail.com ,11/19/2018
asdasddsa@hotmail.com ,11/19/2018
asdasasd@gmail.com ,11/18/2018

以下是我目前所拥有的：

    public static void Main(string[] args)
    {
        SmtpClient smtp = new SmtpClient();
        int SMTP_PORT = 587; 
        Int32.TryParse(ConfigurationManager.AppSettings["SMTP_PORT"], out SMTP_PORT);
        smtp.Port = SMTP_PORT;
        smtp.Credentials = new NetworkCredential(ConfigurationManager.AppSettings["SMTP_USERNAME"], ConfigurationManager.AppSettings["SMTP_PASSWORD"]);
        smtp.Host = ConfigurationManager.AppSettings["SMTP_HOST"];
        string mailFrom = ConfigurationManager.AppSettings["SMTP_MAIL_FROM"];
        string mailSubject = ConfigurationManager.AppSettings["SMTP_MAIL_SUBJECT"];  

        using (SqlConnection connection = new SqlConnection(ConfigurationManager.AppSettings["AzureDBConnString"]))
        {
            connection.Open();

            var queryString = @"SELECT * FROM MyTable WHERE Status = 1";

            using (SqlCommand command = new SqlCommand(queryString, connection))
            {
                command.CommandTimeout = 120;
                SqlDataReader reader = command.ExecuteReader();

                if (reader.HasRows)
                {
                    while (reader.Read()) // loop each user and send email
                    {
                        bool emailSentSuccess = true;
                        using (MailMessage mail = new MailMessage())
                        {
                            try
                            {
                                mail.From = new MailAddress(mailFrom);
                                mail.To.Add(new MailAddress(reader["EmailAddress"].ToString()));
                                mail.IsBodyHtml = true;
                                mail.Subject = mailSubject;
                                mail.Body = reader["EmailBody"].ToString();
                                smtp.Send(mail);
                            }
                            catch (Exception ex)
                            {
                                emailSentSuccess = false;
                            }
                        }
                    }
                }
            }
        }
    }

问题: 我怎样才能达到第 5、6、7 点？

Answer 1

您可以在SqlCommand中参考以下代码。

using (SqlCommand command = new SqlCommand(queryString, connection))
{
    command.CommandTimeout = 120;
    SqlDataReader reader = command.ExecuteReader();
    if (reader.HasRows)
    {
        StringBuilder sb = new StringBuilder();
        List<string> columnNames = new List<string>();
        List<string> rows = new List<string>();
        for (int i = 0; i < reader.FieldCount; i++)
        {
            string tmpColumnName = reader.GetName(i);
            columnNames.Add(tmpColumnName);
        } 
        sb.Append(string.Join(",", columnNames.ToArray())).Append("\r\n");
        List<string> currentRow = new List<string>();
        while (reader.Read())
        {
            for (int i = 0; i < reader.FieldCount; i++)
            {
                object item = reader[i];
                sb.Append(item.ToString().Replace(",", ";") + ',');
            }
            sb.Append("\r\n");
        }
        bool emailSentSuccess = true;
        using (MailMessage mail = new MailMessage())
        {
            try
            {
                using (MemoryStream stream = new MemoryStream(Encoding.ASCII.GetBytes(sb.ToString())))
                {
                    Attachment attachment = new Attachment(stream, new ContentType("text/csv"));
                    attachment.Name = "hello.csv";
                    mail.Attachments.Add(attachment);
                    mail.From = new MailAddress(mailFrom);
                    mail.To.Add(new MailAddress(reader["EmailAddress"].ToString()));
                    mail.IsBodyHtml = true;
                    mail.Subject = mailSubject;
                    mail.Body = reader["EmailBody"].ToString();
                    smtp.Send(mail);
                }
            }
            catch (Exception ex)
            {
                emailSentSuccess = false;
            }
        }
    }
}

我测试的输出如下：