已经有一个与这个命令相关联的打开的数据读取器，必须先关闭它

本文关键字：读取 数据 有一个 命令 关联 | 更新日期: 2023-09-27 18:09:46

我正在制作一个[WebMethod] . .我想在里面添加一行....我想要信用卡和借方…?

public DataSet getleger(string accno, string fromdate, string todate)
{
    SqlConnection con = new SqlConnection(@"Data Source=123-PC;Initial Catalog=bcounts;Persist Security Info=True;User ID=Saba;Password=123");
    con.Open();
    SqlCommand cmd = new SqlCommand("select Convert(nvarchar(10),gt.Value_Date,111) as [Value_Date],gt.Voucher_no+'-'+gr.VchrType as voucher,gt.Acct_Nirration,gr.InstrumentNo,gt.Dr_Amount,gt.Cr_Amount  from gl_transaction gt, Gl_Ref gr where gt.Accountno = '" + accno + "'  and gt.Voucher_No=gr.Voucher_no  and gt.Value_Date between '" + fromdate + "' and '" + todate + "'", con);
    SqlDataAdapter adp = new SqlDataAdapter(cmd);
    DataSet ds = new DataSet("Ledger");
    adp.Fill(ds);
    con.Close();

}

已经有一个与这个命令相关联的打开的数据读取器，必须先关闭它

我不会这样写。内联变量是SQL注入的源。你真应该这样做。

我也会把你的连接字符串移出你的方法。不需要重复声明。

private SqlConnection con { get; set; }
public void SetConnection(string server, string database, string username, string password)
{
    con = new SqlConnection(String.Format("Data Source={0};Initial Catalog={1};Persist Security Info=True;User ID={2};Password={3}", server, database, username, password));
}
public DataSet getleger(string accno, string fromdate, string todate)
{
    try
    {
        con.Open();
        using (SqlCommand cmd = con.CreateCommand())
        {
            cmd.CommandText = "select Convert(nvarchar(10),gt.Value_Date,111) as [Value_Date],gt.Voucher_no+'-'+gr.VchrType as voucher,gt.Acct_Nirration,gr.InstrumentNo,gt.Dr_Amount,gt.Cr_Amount  from gl_transaction gt, Gl_Ref gr where gt.Accountno = @accno and gt.Voucher_No=gr.Voucher_no  and gt.Value_Date between @fromdate and @todate";
            cmd.Parameters.AddWithValue("@accno", accno);
            cmd.Parameters.AddWithValue("@fromdate", fromdate);
            cmd.Parameters.AddWithValue("@todate", todate);
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
                using (DataSet ds = new DataSet())
                {
                    da.Fill(ds);
                    return ds;
                }
            }
        }
    }
    catch (SqlException se)
    {
        //handle error
    }
}

向数据集添加一行

DataRow row = ds.Tables["TableName"].NewRow();
row["Column1"] = "Stuff";
row["Column2"] = "More Stuff";
ds.Tables["TableName"].Rows.Add(row);

如果你想从查询中总结列，你应该在sql查询中这样做。

SELECT SUM(column_name) FROM table_name;
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