C#的oracle查询问题
请各位帮忙
我想把oracle里查询结果输出到listbox里,代码如下,但是执行时报da.Fill(ds);有错,不知是哪里出了问题
//本机连接oracle,我想把表PV里的pv列输出到listbox里
public class ConnDb
{
OracleConnection conn = null;
public ConnDb()
{
if (conn==null)
{
conn = new OracleConnection();
conn.ConnectionString="data source=host;user id=system;password=system;";
}
if (conn.State == ConnectionState.Closed)
{
conn.Open();
}
}
public DataSet query(string sql)
{
DataSet ds = new DataSet();
OracleDataAdapter da = new OracleDataAdapter(sql,conn);
da.Fill(ds);
connClose();
return ds;
}
public void connClose()
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
}
}
}
void Button1Click(object sender, EventArgs e)
{
string sql = string.Format("select * from PV;");
DataSet ds = new ConnDb().query(sql);
this.listBox1.DisplayMember = "PV";
this.listBox1.DataSource=ds.Tables[0];
}