我用OleDBAdapter.Update(dataset,"MyTable")报错，怎么办啊？

[seerzfm]

报错如下：
System.Data.OleDb.OleDbException: 操作必须使用一个可更新的查询。 at System.Data.Common.DbDataAdapter.Update(DataRow[] dataRows, DataTableMapping tableMapping) at System.Data.Common.DbDataAdapter.Update(DataSet dataSet, String srcTable) at localhost.WebForm1.LinkButton1_Click(Object sender, EventArgs e) in c:\inetpub\wwwroot\fsgame\login.aspx.cs:line 73

代码：
dataset.Tables["MyTable"].Rows[0]["Name"] = "zzz";
int result = adapter.Update(ds,"City");

我把第一句注释掉，程序就没有错误。这是怎么回事啊？

[mycjing]

你的adapter的selectComand的查询没有主键或唯一索引

[seerzfm]

谢谢 ，怎么在selectComand中加主键或唯一索引。？这是我的代码，多谢了
string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Password=;User ID=Admin;Data Source="
+ Server.MapPath("DataBase\\FSGame.mdb") + ";";
OleDbConnection conn = new OleDbConnection(strConn);
string strCmd = "select CityID,CityName from City";//CityID是主键
OleDbDataAdapter adapter = new OleDbDataAdapter(strCmd,conn);
OleDbCommandBuilder cb = new OleDbCommandBuilder(adapter);
conn.Open();
DataSet ds = new DataSet();
adapter.Fill(ds,"City");
ds.Tables["City"].Rows[0]["CityName"] = "zzz";
int result;
result = adapter.Update(ds,"City");
Label1.Text = result.ToString();
conn.Close();