单击按钮更新

Question

我有一个按钮，代码没问题，但更新时出错。

这是代码：

private void button1_Click(object sender, EventArgs e)
{
   SqlConnection conn = new SqlConnection();
   conn.ConnectionString = "Data Source=PEWPEWDIEPIE\\SQLEXPRESS;Initial Catalog=master;Integrated Security=True";
   conn.Open();

   SqlCommand cmdC = conn.CreateCommand();
   cmdC.CommandText = "Update ComDet set cDetails = " + lblcDetails.Text + ", cDetails2 = '" + lblcDetails2.Text + "', PhoneNumber = '" + lblPhoneNumber.Text + "', PersonCharge = '" + lblPersonInCharge.Text + "' Where cName = '" + lblcNameP.Text + "'";
   cmdC.ExecuteNonQuery();
   MessageBox.Show("Data Updated");

}

这是错误..

链接到更大图片的错误：Error Picture

表单如下所示：

现在在我的脑海里，错误可能是文本框中的空格..但我不知道是不是。

谁能指出我哪里做错了？

Answer 1

请不要在sql命令中使用字符串连接。您可能会遗漏一些引号，很难找到它的位置。使用parameterized queries。

此类连接也可用于SQL Injection次攻击。

SqlCommand cmdC = conn.CreateCommand();
cmdC.CommandText = "Update ComDet set cDetails = @cDetails , cDetails2 = @cDetails2, PhoneNumber = @PhoneNumber, PersonCharge = @PersonCharge  Where cName = @cName";
cmdC.Parameters.AddWithValue("@cDetails", lblcDetails.Text);
cmdC.Parameters.AddWithValue("@cDetails2", lblcDetails2.Text);
cmdC.Parameters.AddWithValue("@PhoneNumber", lblPhoneNumber.Text);
cmdC.Parameters.AddWithValue("@PersonCharge  ", lblPersonInCharge.Text);
cmdC.Parameters.AddWithValue("@cName", lblcDetails.Text);
cmdC.ExecuteNonQuery();

Answer 2

更改初始catalog.put ypur表名称

conn.ConnectionString = "Data Source=PEWPEWDIEPIE\\SQLEXPRESS;Initial Catalog=Datbasename;Integrated Security=True";

试试这个

cmd.Parameters.AddWithValue("@FirstDetail",textbox1.text);

cmd.Parameters.AddWithValue("@SecondDetail", Textbox2.Text);

refer here

Answer 3

为了避免语法错误，请将格式化字符串用作

cmdC.CommandText =string.Format("Update ComDet set cDetails = '{0}',cDetails2 ='{1}',PhoneNumber = '{2}',PersonCharge = '{3}' Where cName = '{4}'", lblcDetails.Text, lblcDetails2.Text , lblPhoneNumber.Text , lblPersonInCharge.Text , lblcNameP.Text );

Answer 4

我猜两件事情都不正确：

在数据源上，初始目录引用数据库的名称。你有“主人”。应该像：

conn.ConnectionString = "Data Source=PEWPEWDIEPIE\\SQLEXPRESS;Initial Catalog=yourDBname;Integrated Security=True";

此外，您在SQL语句中缺少引号（并且它们的顺序并不总是正确），它应该是：

cmdC.CommandText = "Update ComDet set cDetails = '" + lblcDetails.Text + "', cDetails2 = '" + lblcDetails2.Text + "', PhoneNumber = '" + lblPhoneNumber.Text + "', PersonCharge = '" + lblPersonInCharge.Text + "' Where cName = '" + lblcNameP.Text + "'";