我在连接到 MS Access DB 2007 时遇到问题。代码:
private void btnSave_Click(object sender, EventArgs e)
{
OleDbConnection Conn = new OleDbConnection();
try
{
string conn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source="+ Directory.GetCurrentDirectory() +"\\dvd_manager.accdb;Persist Security Info=False;";
Conn.ConnectionString = conn;
Conn.Open();
int i = cbbLocatie.SelectedIndex + 65;
char c = (char)i;
string sql = "INSERT INTO DVD (titel, locatie)VALUES(@titel, @locatie)";
OleDbCommand Com = new OleDbCommand();
Com.CommandText = sql;
Com.Connection = Conn;
OleDbParameter Param = new OleDbParameter("@titel", txtTitle.Text);
Com.Parameters.Add(Param);
Param = new OleDbParameter("@locatie", c);
Com.Parameters.Add(Param);
Com.ExecuteNonQuery();
Conn.Close();
MessageBox.Show("Data is opgeslagen " + sql);
}
catch (Exception ex)
{
MessageBox.Show("Fout opgetreden: " + ex.Message);
}
finally
{
Conn.Close();
}
}
当我运行此代码时,会出现消息框。这应该意味着我的数据已插入。但是当我打开 accdb 文件时,没有插入数据。我究竟做错了什么?
Thnx
编辑:
ExecuteNonQuery()的返回值是1(我编辑我的帖子,因为我无法添加任何评论,当我单击添加评论时,该框不会显示..)
编辑2:
我创建了一个具有 Title 和 Location 属性的类。代码:
私人无效btnSave_Click(对象发送者,EventArgs e)
{
OleDbConnection Conn = new OleDbConnection();
try
{
string conn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source="+ Directory.GetCurrentDirectory() +"\\dvd_manager.accdb;Persist Security Info=False;";
Conn.ConnectionString = conn;
// Create object
Medium M = new Medium();
int i = cbbLocatie.SelectedIndex + 65;
char c = (char)i;
M.Location = c;
M.Title = txtTitle.Text;
Conn.Open();
string sql = "INSERT INTO DVD (titel, locatie)VALUES(@titel, @locatie)";
OleDbCommand Com = new OleDbCommand();
Com.CommandText = sql;
Com.Connection = Conn;
OleDbParameter Param1 = new OleDbParameter("@titel", M.Title);
Com.Parameters.Add(Param1);
OleDbParameter Param2 = new OleDbParameter("@locatie", M.Location);
Com.Parameters.Add(Param2);
int ret = Com.ExecuteNonQuery();
Conn.Close();
MessageBox.Show("Data is opgeslagen " + ret);
}
catch (OleDbException ex)
{
MessageBox.Show(ex.Message);
}
catch (Exception ex)
{
MessageBox.Show("Fout opgetreden: " + ex.Message);
}
finally
{
Conn.Close();
}
}
由于我仍然无法单击“添加注释”按钮,因此这是带有无名 sql 参数的新代码:
// some code
Conn.Open();
string sql = "INSERT INTO DVD (titel, locatie)VALUES(?, ?)";
OleDbCommand Com = new OleDbCommand();
Com.CommandText = sql;
Com.Connection = Conn;
OleDbParameter Param1 = new OleDbParameter("@p1", OleDbType.VarChar, 1);
Param1.Value = M.Title;
Com.Parameters.Add(Param1);
OleDbParameter Param2 = new OleDbParameter("@p2", OleDbType.VarChar, 255);
Param2.Value = M.Location;
Com.Parameters.Add(Param2);
int ret = Com.ExecuteNonQuery();
Conn.Close();
// morde code