Question

Hello Everyone我想获得end_date，格式为2014-01-01

我想使用我的减法方法（有效）和我在end_date中查询什么，所以我可以创建一个if方法来查看他们的订阅是否付费但我不知道如何使查询读取end_date并进行比较到目前为止

这是我目前的代码：

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

这样的事情应该让你开始：

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更改为您的表名称。除此之外，我认为它应该有效。

MYSQL C＃get days left查询

1 个答案: