Question

string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\Samples\\login.mdb";
String uname, pass;
uname = textBox1.Text;

pass = textBox2.Text; 
OleDbConnection myConnection = new OleDbConnection(connectionString);
myConnection.Open();

String query = "insert into LOGIN_TABLE (UserName, Password) VALUES ('" +
    textBox1.Text.ToString() + "','" + textBox2.Text.ToString() + "') ";


OleDbCommand myCommand = new OleDbCommand();
myCommand.CommandText = query;
OleDbParameter myParm = myCommand.Parameters.Add("@uname", OleDbType.VarChar, 50);
myParm.Value = textBox1.Text;

myParm = myCommand.Parameters.Add("@pass", OleDbType.VarChar, 50);
myParm.Value = textBox2.Text;

myCommand.ExecuteNonQuery();
myConnection.Close();

Answer 1

您尚未告知OleDbCommand要使用哪个数据库连接。

尝试这样做：

OleDbCommand myCommand = new OleDbCommand(query, myConnection);

然后不要在下一行设置CommandText属性。

更新： Marc是对的，你甚至没有使用你的参数，因为你的查询定义不适合所谓的准备语句。试试这个：

string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\Samples\\login.mdb";

using (OleDbConnection myConnection = new OleDbConnection(connectionString))
{
    myConnection.Open();

    string query = "INSERT INTO LOGIN_TABLE (UserName, Password) VALUES (?, ?)";

    OleDbCommand myCommand = new OleDbCommand(query, myConnection);

    myCommand.Parameters.Add("UserName", OleDbType.VarChar, 50);
    myCommand.Parameters.Add("Password", OleDbType.VarChar, 50);

    myCommand.Parameters[0].Value = textBox1.Text;
    myCommand.Parameters[1].Value = textBox2.Text;

    myCommand.Prepare();
    myCommand.ExecuteNonQuery();
}

我摆脱了一些不必要的任务，并以不同的方式设置命令参数。试一试，让我知道是否能解决您的问题。

ExecuteNonQuery收到错误：Connection属性尚未初始化

1 个答案: