连接到 MDF 数据库

Question

In Visual Studio Form, Im creating ac# application. Im an trying to add data entered into a register form and save it into the MDF Database file i cretased with tables. But i cant connect to the database, Any Help?

My Register Button Code when its clicked

private void CreateAccBtn_Click(object sender, EventArgs e)
{
    string ConnectToDatabase = ("Data Source=  (LocalDB)\v11.0;AttachDbFilename=E:\\Work\\Information Systems      Development\\Game\\My Brain Cognitive Game\\My Brain Cognitive Game\\Brain Game Database.mdf;Integrated Security=True;Connect Timeout=10");
    SqlConnection ConnectDatabase = new SqlConnection(ConnectToDatabase);
    SqlCommand CMDDatabase = new SqlCommand("Insert Into Brain Game Database.User Table (User Name, Date Of Birth, Gender, Date Account Created, Condition, Email, Password) values('" + this.NewUsernameTxtBox.Text + "','" + this.DOBDateTimePicker3.Text + "','" + this.SexListBox1.Text + "','" + this.CurrentDatePicker1.Text + "','" + this.NewConditionTxtBox.Text + "','" + this.NewEmailTxtBox.Text + "','" + this.NewPasswordTxtBox.Text + "');",ConnectDatabase);
    SqlDataReader MyReader;
    try
    {
         ConnectDatabase.Open();
         MyReader = CMDDatabase.ExecuteReader();
         MessageBox.Show("Account Created");
         while (MyReader.Read())
         {

         }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}  

Answer 1

There are a few things to help you get connected. I just helped several students had their connections done this week.

Please double check your connection string is correct (pointing to the right location - path of your .MDF file)

1. Make sure the connection string is correct.
2. Try not to have duplicate database in your project.
3. Make sure the path to your database in all settings are correct (having duplicate database may confuse you here)
4. When adding new connection, there is a Test Connection button. Click it and ensure connection is working before you try to execute query from the codes.
5. Once everything is done, Use the Select * FROM tblName query statement to test first instead of using an insert statement which is more prone to typo error.

You can try the following (instead of using a SqlCommand object):

string queryStr = "YOUR SQL QUERY HERE";
SqlCommand cmd = new SqlCommand(queryStr, new SqlConnection(connectionString));
cmd.Connection = sqlConnection;
sqlConnection.Open();
cmd.ExecuteNonQuery();
sqlConnection.Close();