MYSQL C# get days days查询

Question

大家好，我想得到的end_date格式是2014-01-01

我想使用我的减法(它可以)来查询end_date中的内容，这样我就可以创建一个if方法来查看它们的订阅是否已经支付，但是我不知道如何使一个查询读取end_date并比较它到现在为止。

下面是我当前的代码：

string myConnection = "server=****;user=****;database=***;port=3306;password=***;";
                MySqlConnection myConn = new MySqlConnection(myConnection);
                MySqlCommand SelectCommand = new MySqlCommand("SELECT end_date FROM username = '" + this.username_txt.Text + "'", myConn);
                MySqlDataReader myReader;
                myConn.Open();
                DateTime endDate = get end_date from query here???;
                var DaysLeft = (endDate.Date - now.Date).Days;
                MessageBox.Show(""+ DaysLeft);

Answer 1

像这样的事情应该会让你开始：

string myConnection = "server=****;user=****;database=***;port=3306;password=***;";
MySqlConnection myConn = new MySqlConnection(myConnection);
MySqlCommand cmd = conn.CreateCommand(); 
SELECT DATEDIFF(NOW(), your_date)
cmd.CommandText = "SELECT DATEDIFF(NOW(), end_date) FROM TABLE WHERE username = '" + this.username_txt.Text + "'";
myConn.Open();
MessageBox.Show(cmd.ExecuteScalar());

将TABLE更改为表的名称。除此之外，我认为它应该是有效的。