c data binding adds the parameter ES1en.Net to the query to connect to an external database

The operation string can be defined in ACCESS database as MSSQL or as OLEDB.

MSSQL form

string sqlText = @"SELECT * FROM [User] WHERE UserName= @name";

The form of OLEDB

string sqlText = @"SELECT * FROM [User] WHERE UserName=  ? ";

The next step is to perform the operation via OleDbCommand.

OleDbCommand dataAction = new OleDbCommand(sqlText,linkDB);

The parameter assignment statement is AddWithValue:

dataAction.Parameters.AddWithValue("@name","wangyong");

The complete code is as follows:

using (OleDbConnection linkDB = new OleDbConnection(@" Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\AiMeiLi.accdb"))
            {
                linkDB.Open();
                string sqlText = @"SELECT * FROM [User] WHERE UserName= @name";
                OleDbCommand dataAction = new OleDbCommand(sqlText,linkDB);
                dataAction.Parameters.AddWithValue("@name","wangyong");
                try
                {
                    OleDbDataReader scanItems = dataAction.ExecuteReader();
                    if (scanItems.HasRows)
                    {
                        while (scanItems.Read())
                        {
                            MessageBox.Show(scanItems[1].ToString());
                        }
                    }

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