[英]update data using oledb in c#
我使用c#和访问accdb创建了一个数据库项目,并在两者之间建立了连接。 我做了2个按钮,第一个按钮添加了新的客户程序,效果很好,第二个按钮更新了客户程序的数据(名字和姓氏),由于某种原因,更新按钮不起作用,当出现错误时我运行了该项目,但是单击后什么也没有发生...
private void button2_Click(object sender, EventArgs e)
{
connect.Open();
string cid = textBox1.Text;
string cfname = textBox2.Text;
string clname = textBox3.Text;
OleDbCommand command = new OleDbCommand();
command.Connection = connect;
command.CommandText = "UPDATE Tcostumers SET cfname= " + cfname + "clname= " + clname + " WHERE cid = " + cid;
if (connect.State == ConnectionState.Open)
{
try
{
command.ExecuteNonQuery();
MessageBox.Show("DATA UPDATED");
connect.Close();
}
catch (Exception expe)
{
MessageBox.Show(expe.Source);
connect.Close();
}
}
else
{
MessageBox.Show("ERROR");
}
}
我相信您的命令文本就是麻烦所在。
command.CommandText = "UPDATE Tcostumers SET cfname= " + cfname + "clname= " + clname + " WHERE cid = " + cid;
您需要在set语句之间加上逗号,就像Gino指出的语音标记一样。
编辑:
这比使用变量参数更好,因为当前方法可以进行SQL注入,例如。
private void button2_Click(object sender, EventArgs e)
{
OleDbCommand command = new OleDbCommand(@"UPDATE Tcostumers
SET cfname = @CFName,
clname = @CLName
WHERE cid = @CID", connect);
command.Parameters.AddWithValue("@CFName", textBox2.Text);
command.Parameters.AddWithValue("@CLName", textBox3.Text);
command.Parameters.AddWithValue("@CID", textBox1.Text);
try
{
connect.Open();
}
catch (Exception expe)
{
MessageBox.Show(expe.Source);
}
try
{
command.ExecuteNonQuery();
MessageBox.Show("DATA UPDATED");
}
catch (Exception expe)
{
MessageBox.Show(expe.Source);
}
finally
{
connect.Close();
}
}
这就是我倾向于格式化代码的方式,因此请按照自己的意愿去做。 希望能帮助到你。
这可能是愚蠢的事情,但是...
您要更新的字符串不是整数,因此请尝试在字符串中添加“”,例如:
command.CommandText = "UPDATE Tcostumers SET cfname= '" + cfname + "' clname='" + clname + "' WHERE cid = " + cid;
//my sample code for edit/update
Table Name = StudentFIle
Fields = id,fname,lname
bool found = false;
OleDbConnection BOMHConnection = new OleDbConnection(connect);
string sql = "SELECT * FROM StudentFIle";
BOMHConnection.Open();
OleDbCommand mrNoCommand = new OleDbCommand(sql, BOMHConnection);
OleDbDataReader mrNoReader = mrNoCommand.ExecuteReader();
while (mrNoReader.Read())
{
if (mrNoReader["id"].ToString().ToUpper().Trim() == idtextbox.Text.Trim())
{
mrNoReader.Close();
string query = "UPDATE StudentFIle set fname='" +firstnametextbox.Text+ "',lname='"+lastnametextbox.Text+"' where id="+idtextbox.Text+" ";
mrNoCommand.CommandText = query;
mrNoCommand.ExecuteNonQuery();
MessageBox.Show("Successfully Updated");
found = true;
break;
}
continue;
}
if (found == false)
{
MessageBox.Show("Id Doesn't Exist !.. ");
mrNoReader.Close();
BOMHConnection.Close();
idtextbox.Focus();
}
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