string StrSQL = "SELECT * from test where name='zhansan'";
OleDbCommand selCmd=new OleDbCommand(StrSQL,myConn);
selCmd.Connection.Open();
OleDbDataReader Dr;
Dr=selCmd.ExecuteReader();
if(Dr.Read())
{
if(!this.IsPostBack )
{
string mySql="SELECT school_name from school where id='"+Dr["id"].toString()+"'";
OleDbCommand myCmd=new OleDbCommand(mySql,myConn);
myCmd.Connection.Open();
OleDbDataReader Dr1;
Dr1=myCmd.ExecuteReader();
while(Dr.Read())
{
schoollist.Items.Add(Dr1.GetString(0).Trim());
}
Dr1.Close();
myCmd.Connection.Close();
}
Dr.Close();
selCmd.Connection.Close(); 上面这个程序报Connection已经打开,
是不是selCmd.Connection.Close();和myCmd.Connection.Open();有错,该如何解决?
OleDbCommand selCmd=new OleDbCommand(StrSQL,myConn);
selCmd.Connection.Open();
OleDbDataReader Dr;
Dr=selCmd.ExecuteReader();
if(Dr.Read())
{
if(!this.IsPostBack )
{
string mySql="SELECT school_name from school where id='"+Dr["id"].toString()+"'";
OleDbCommand myCmd=new OleDbCommand(mySql,myConn);
myCmd.Connection.Open();
OleDbDataReader Dr1;
Dr1=myCmd.ExecuteReader();
while(Dr.Read())
{
schoollist.Items.Add(Dr1.GetString(0).Trim());
}
Dr1.Close();
myCmd.Connection.Close();
}
Dr.Close();
selCmd.Connection.Close(); 上面这个程序报Connection已经打开,
是不是selCmd.Connection.Close();和myCmd.Connection.Open();有错,该如何解决?
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OleDbCommand selCmd=new OleDbCommand(StrSQL,myConn);
selCmd.Connection.Open();
//OleDbDataReader Dr;
//Dr=selCmd.ExecuteReader();
OleDbDataAdapter da=new OleDbDataAdapter(selCmd,myConn);
DataTable dt=new DataTable();
da.Fill(dt);
//if(Dr.Read())
if(dt.Rows.Count>0)
{
if(!this.IsPostBack )
{
//string mySql="SELECT school_name from school where id='"+Dr["id"].toString()+"'";
string mySql="SELECT school_name from school where id='"+Dt[0]["id"].toString()+"'";
OleDbCommand myCmd=new OleDbCommand(mySql,myConn);
myCmd.Connection.Open();
OleDbDataReader Dr1;
Dr1=myCmd.ExecuteReader();
//while(Dr.Read())
int i;
for(i=0;i<dt.Rows.Count;i++)
{
schoollist.Items.Add(Dr1.GetString(0).Trim());
}
Dr1.Close();
myCmd.Connection.Close();
}
//Dr.Close();
selCmd.Connection.Close();
我没实际运行只是这么想。
换成myconn.Open();
试试!