更新查询语法正确吗? [英] is the update query syntax correct?

问题描述

我是新手，所以不要对我的问题生气，我的英语也很弱
我已经编辑了插入查询之前的查询，并且已经编辑成为uodate查询，但是最后一部分不正确，因为数据更新成功了，但是如果更新成功，我想显示一个消息框，那么它将是成功的，如果更新失败，然后将显示一个消息框，其中包含错误消息.
这是我疯狂的代码

i am newbie so dont angry on my question also i am weak in english
i have edited my query which was before an insert query and i have edited to become a uodate query but the last portion is not correct as data is updated successfull but i want to show a messagebox if updation was success then it will be suceess and if updation was failed then a message box will show which will contain message of error.
here is my crazy code

SqlConnection conn = new SqlConnection();
          conn.ConnectionString = @"Data Source=.\SQLEXPRESS;AttachDbFilename=E:\project\Projects\labelnameinsecondformtry\labelnameinsecondformtry\Database1.mdf;Integrated Security=True;User Instance=True";
          try
          {
              conn.Open();
          }
          catch (Exception)
          {
              MessageBox.Show("Error with the databse connection");
          }
          string qry2 = "UPDATE Table1 SET Password =@Password WHERE UserName=@username";
          SqlCommand com = new SqlCommand(qry2, conn);
          com.Parameters.AddWithValue("@username", this.textBox1.Text);
          com.Parameters.AddWithValue("@Password", this.textBox2.Text);
          SqlDataReader dr = com.ExecuteReader();
          while (dr.Read())
          {
              if (dr.HasRows == true)
              {
                  MessageBox.Show("updated sucesfull");
              }
          }
          if (dr.HasRows == false)
          {
              MessageBox.Show("updation failed ");
          }

推荐答案

阿迪尔，

请按以下方式更新您的代码.

Hi Adil,

Please update your code as below.

SqlConnection conn = new SqlConnection();
            conn.ConnectionString = @"Data Source = .\SQLEXPRESS;AttachDbFilename=E:\project\Projects\labelnameinsecondformtry\labelnameinsecondformtry\Database1.mdf;Integrated Security=True;User Instance=True";
       try
       {
            conn.Open();
            string qry2 = "UPDATE Table1 SET Password =@Password WHERE UserName=@username";
            SqlCommand com = new SqlCommand(qry2, conn);
            com.Parameters.AddWithValue("@username", this.textBox1.Text);
            com.Parameters.AddWithValue("@Password", this.textBox2.Text);
            int result = com.ExecuteNonQuery();
            if (result > 0)
            {
                MessageBox.Show("updated sucesfull");
            }
            else
                 MessageBox.Show("updated failed");
         }
         catch (Exception)
         {
                MessageBox.Show("Error with the databse connection");
         }

希望对您有所帮助.

Hope this will help you.

请尝试以下操作:

Try the following:

int x = cmd.ExecuteNonQuery();
if (x == -2)
{
   //fail and show the message
}

请检查以下示例:

http://stackoverflow.com/Questions/2963703/how-to-know-a-sql-update-statement-exected-successfully-or-failed [

please check the following for example:

http://stackoverflow.com/questions/2963703/how-to-know-whether-a-sql-update-statement-executed-successfully-or-failed[^]

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