我想创建一个注册表单。我想进行验证检查,如果文本框中的ID已经存在,它会显示错误消息。然而,每当我尝试搜索ID,并把它转换成字符串我得到一个错误C#SQL搜索结果到一个字符串/文本框
An unhandled exception of type 'System.Data.SqlServerCe.SqlCeException' occurred in System.Data.SqlServerCe.dll
这里是我的代码:
public SignUpForm()
{
InitializeComponent();
}
// Connection String
SqlCeConnection connect = new SqlCeConnection("Data Source= Accounts.sdf;Persist Security Info=false;");
private void btnRegister_Click(object sender, EventArgs e) {
String verifyID = "";
connect.Open();
using (SqlCeCommand cmd = new SqlCeCommand("SELECT Student ID FROM Users WHERE Student ID = @ID", connect))
{
cmd.Parameters.AddWithValue("@ID", txtID.Text);
using (SqlCeDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
verifyID = (string)reader["Student ID"];
}
}
}
txtTEMP.Text = verifyID;
即使列名在他们的空间?我仍然得到错误 – user2782104
请看Saagar的回答:) – Minh