下面的代码为什么不能更改数据库里的数据呢？

[adafirst3219]

private void Form1_Load(object sender, System.EventArgs e)
{
SqlConnection cn=new SqlConnection("Data Source=(local);User id=sa;Initial Catalog=Northwind");
System.Data.SqlClient.SqlDataAdapter da=new SqlDataAdapter("Select * from Categories",cn);
da.UpdateCommand=new SqlCommand("Select * from Categories",cn);
SqlCommandBuilder dcb=new System.Data.SqlClient.SqlCommandBuilder(da);
DataSet ds=new DataSet("Ctgrs");
cn.Open();
da.Fill(ds,"Categories");
DataTable dt=ds.Tables[0];
DataRow dr=dt.Rows[1];
// byte[] sm=(byte[])dr["Picture"];
// FileStream fs=File.Open("c:\\b.jpg",FileMode.Create,FileAccess.ReadWrite);
// fs.Write(sm,0,sm.Length);
FileStream fs=File.Open("c:\\a.jpg",FileMode.Open,FileAccess.Read);
byte[] sm=new byte[fs.Length];
fs.Read(sm,0,(int)fs.Length);
// dr.BeginEdit();
dr["Description"]="alsdkjfaskdfjaskdfasdkjfaskdjf";
dr["Picture"]=sm;
// dr.EndEdit();
da.Update(ds.Tables[0]);
// MessageBox.Show(this,"Update Successfully");
da.Dispose();
fs.Close();
cn.Close();
}

[iamangling]

把
da.UpdateCommand=new SqlCommand("Select * from Categories",cn);
去掉试试看！

[hhzh426]

da.UpdateCommand=new SqlCommand("Select * from Categories",cn);
更新的语句不是这么写的。

[adafirst3219]

哇，厉害