我的代码中最后一个字符串出现了问题。
这是我的代码:
private void comboLname_SelectedIndexChanged(object sender, EventArgs e)
{
string conn = "Data Source=srv-db-02;Initial Catalog=rmsmasterdbtest;Persist Security Info=True;User ID=test;Password=*****";
string Query = "select * from RMSCRMTest.dbo.sales where LastName= '" + comboLname.Text + "' ;";
SqlConnection Myconn = new SqlConnection(conn);
SqlCommand cmdDataBase = new SqlCommand(Query, Myconn);
SqlDataReader Reader;
try
{
Myconn.Open();
Reader = cmdDataBase.ExecuteReader();
while (Reader.Read())
{
string ID = Reader.GetInt32(Reader.GetOrdinal("ID")).ToString();
string AccountNuber = Reader.GetString(Reader.GetOrdinal("AccountNumber")).ToString();
string Time = Reader.GetDateTime(Reader.GetOrdinal("Time")).ToString();
string Deposit = Reader.GetDecimal(Reader.GetOrdinal("Deposit")).ToString();
string slastname = Reader.GetString(Reader.GetOrdinal("lastname"));
string sstatus = Reader.GetString(Reader.GetOrdinal("status"));
txtid.Text = ID;
txtacnum.Text = AccountNuber;
txttime.Text = Time;
txtdeposit.Text = Deposit;
txtlname.Text = slastname;
txtstatus.Text = status;
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
Myconn.Close();
}
}
我在表格中添加了另一列,并将字符串添加到该列后,出现了这个问题。
sstatus = Reader.GetString(Reader.GetOrdinal("status"));
我收到的错误信息是:
其它字符串都可以正常工作。数据为 null,无法在 null 值上调用此方法或属性。