您能帮我解决我的问题吗？我使用的是SQL Server数据库,它是一个体操程序,我想在他来健身房时向客户端进行检查,我有两种方式提供服务,第一种是每月一次,第二种是每天,首先,我没有问题,并使用此代码进行签入；

using (SqlCommand com = new SqlCommand("select count(*)from enddate where ID=@ID and startdate <=@C1 and endDate >=@C2", con))
                {

                    com.Parameters.AddWithValue("@ID", ID.Text);
                    com.Parameters.AddWithValue("@C1", DateTime.Now);
                    com.Parameters.AddWithValue("@C2", DateTime.Now);

                    int count = (int)com.ExecuteScalar();
                    if (count > 0)
                    {
                        using (SqlCommand com1 = new SqlCommand("INSERT INTO [checkin] (ID,time,username) VALUES (@ID,@time,@username)", con))
                        {
                            com1.Parameters.AddWithValue("@ID", ID.Text);

                            com1.Parameters.AddWithValue("@time", txttime.Text);

                            com1.Parameters.AddWithValue("@username", txtusername.Text);
                            com1.ExecuteNonQuery();
                        }
                        MetroFramework.MetroMessageBox.Show(this, "Check In Sucssesfuly ................... ", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    }
                    else
                    {
                        MetroFramework.MetroMessageBox.Show(this, "this ID Expired .....................", "Message", MessageBoxButtons.OK, MessageBoxIcon.Warning);


                    }
                    con.Close();
                }

我想将第二个条件(每日报价)添加到此代码中,我具有enddate表,例如；

| ID | Startdate | month | day | enddate |          offer       |
| 1  | 20-3-2019 |   3   |null |20-6-2019|( summer ) monthly    |
| 2  | 20-3-2019 | null  | 5   |20-3-2019|( student )  daily    |

在这种情况下,第一个可以连续出现3个月,而在第二个ID中,他只能连续出现5次.

我的签到表;

| ID |   Time   | username |
| 1  | 21-3-2019| test     |
| 1  | 25-3-2019| test     |
| 2  | 27-3-2019| test 2   | 

我可以计算出他来健身房的时间,但我不知道如何在代码中添加它

解决方法:

我认为您可能需要重新考虑解决问题的方法.如果我是你我会：

>使用ID.text获取enddate表中的记录,我假设这是您的客户报价表.因此,您具有该客户ID的数据STARTDATE,ENDDATE,Offer和其他信息.
>如果ENDDATE为空,并且Offer = day,则ENDDATE = DATE(Datetime.Now)
>使用ID.text从签入表中计数记录.因此,通过使用以下语句,您获得了多次访问.

从检入中选择COUNT(*)WHERE Time> = STARTDATE and(Time< = ENDDATE)
>您现在有了访问次数,您可以设置一个条件来检查客户是否已经用完“天”(5天).

花了一些时间后,我尝试用C#完成您的整个逻辑：

var goodForVisit = false;
int visitedCount;
int offerDayCount;
var endDate = DateTime.MinValue;
DateTime startDate = DateTime.MinValue;

using (SqlCommand com = new SqlCommand("select * from [enddate] where ID=@ID", con))
{
    com.Parameters.AddWithValue("@ID", ID.Text);
    using (SqlDataReader reader = com.ExecuteReader())
    {
        if (reader.Read())
        {
            //get information from enddate table
            var offer = “”;
            if(reader[“offer”] != null)
                  offer = reader["offer"].ToString();
            if (reader[“day”] != null)
                  offerDayCount = (int)reader["day"];
            startDate = (DateTime)reader["Startdate"];
            if (reader["enddate"] != null)
                endDate = (DateTime)reader["enddate"];


            if (reader["enddate"] == null && offer == "dayly")
            {
                endDate = DateTime.Now.Date;
            }

            //count the visit from checkin table
            using (var com2 = new SqlCommand("SELECT COUNT(*) as count From checkin WHERE Time >= @STARTDATE and (Time <= @ENDDATE)"))
            {
                com.Parameters.AddWithValue("@STARTDATE", startDate);
                com.Parameters.AddWithValue("@ENDDATE", endDate);

                using (SqlDataReader reader2 = com2.ExecuteReader())
                {
                    if (reader2.Read())
                    {
                        visitedCount = (int)reader2["count"];
                        if (offer == "dayly" && visitedCount < offerDayCount)
                            goodForVisit = true;

                        if (offer == "monthly" && DateTime.Now >= startDate && DateTime.Now <= endDate)
                            goodForVisit = true;
                    }
                }
            }
        }
    }
}

if (goodForVisit)
{
    using (SqlCommand com1 = new SqlCommand("INSERT INTO [checkin] (ID,time,username) VALUES (@ID,@time,@username)", con))
    {
        com1.Parameters.AddWithValue("@ID", ID.Text);

        com1.Parameters.AddWithValue("@time", txttime.Text);

        com1.Parameters.AddWithValue("@username", txtusername.Text);
        com1.ExecuteNonQuery();
    }
    MetroFramework.MetroMessageBox.Show(this, "Check In Sucssesfuly ................... ", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
else
{
    MetroFramework.MetroMessageBox.Show(this, "this ID Expired .....................", "Message", MessageBoxButtons.OK, MessageBoxIcon.Warning);
}