DataAdapter.Update提供了一个额外的列 [英] DataAdapter.Update giving an extra column

问题描述

大家好.

我正在使用ODBC Microsoft文本驱动程序将csv文件加载到要在datagridview中显示的数据集中，目前DGV中没有任何列.我可以成功加载文件，但是遇到2个问题:

a)2列可以很好地加载，但是第三个"noname"列也可以加载-为什么会发生这种情况?

b)当我使用DataAdapter进行更新时，出现以下异常:

"ERROR [HYS22] [Microsoft][ODBC Text Driver] The INSERT INTO statement contains the following unknown field name: ''NoName''. Make sure you have typed the name correctly, and try the operation again."

有人知道为什么会这样吗?

非常感谢，
查尔斯

***以下代码***

Hello all.

I''m using the ODBC Microsoft Text Driver to load a csv file into the dataset to be displayed in the datagridview, the DGV has no columns in at present. I can load the file successfully but I encounter 2 problems:

a) The 2 columns load fine but a third ''noname'' column is also loaded - why does this happen?

b) When I do an update using a DataAdapter, I get this exception:

"ERROR [HYS22] [Microsoft][ODBC Text Driver] The INSERT INTO statement contains the following unknown field name: ''NoName''. Make sure you have typed the name correctly, and try the operation again."

Does anybody know why this occurs?

Many thanks,
Charles

*** Code below ***

void RefreshData()
      {
          OdbcConnection conn = new OdbcConnection(@"Driver={Microsoft Text Driver (*.txt; *.csv)};Dbq=c:\;");

          OdbcCommand comm = new OdbcCommand("Select * FROM test.csv", conn);
          OdbcDataAdapter adapter = new OdbcDataAdapter(comm);
          DataSet ds = new DataSet();
          adapter.Fill(ds);
         // ds.Tables[0].Columns.Remove("noname");
          dataGridView1.DataSource = ds.Tables[0];
      }

      private void button1_Click(object sender, EventArgs e)
      {
          OdbcConnection conn = new OdbcConnection(@"Driver={Microsoft Text Driver (*.txt; *.csv)};Dbq=c:\;");
          string qry = "Select * FROM test.csv";
          OdbcDataAdapter da = new OdbcDataAdapter();
          da.SelectCommand = new OdbcCommand(qry, conn);

          OdbcCommandBuilder cb = new OdbcCommandBuilder(da);

          DataSet ds = new DataSet();
          da.Fill(ds);

          //ds.Tables[0].Columns.Remove("noname");

          DataTable dt = ds.Tables[0];

          // Add a row
          DataRow newRow = dt.NewRow();
          newRow[0] = this.textBox1.Text;
          newRow[1] = int.Parse(this.textBox2.Text); ;
          dt.Rows.Add(newRow);

          da.Update(ds.Tables[0]);

          conn.Close();

          this.Refresh();

*** CSV数据***
empName，工资，
查尔斯，4324343，
andrew，31343970，
freddy，998788966，
loop，8878743，

*** csv Data ***
empName,salary,
charles,4324343,
andrew,31343970,
freddy,998788966,
loop,8878743,

推荐答案

在涉及SQL查询时，您永远不要使用SELECT * FROM test.csv，而是要按名称命名要提取的列.因此，如果您这样做

When it comes to SQL queries you should never use SELECT * FROM test.csv, rather name the columns you want to extract by name. Thus if you do this

void RefreshData()
        {
            OdbcConnection conn = new OdbcConnection(@"Driver={Microsoft Text Driver (*.txt; *.csv)};Dbq=C:\;");
            //Get specific columns
            OdbcCommand comm = new OdbcCommand("Select empName, salary FROM test.csv", conn);
            OdbcDataAdapter adapter = new OdbcDataAdapter(comm);
            DataSet ds = new DataSet();
            adapter.Fill(ds);
            dataGridView1.DataSource = ds.Tables[0];
        }

那你应该没事的.

希望这对您有帮助

then you should be OK.

Hope this helps

这是您修改后的更新语句

here is your modifed update statement

da.Update(ds.Tables[0].DefaultView.ToTable(true, new string[] { "empName", "salary" }));

试试这个....

try with this....

这篇关于DataAdapter.Update提供了一个额外的列的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！