Question

我需要返回Test列中的所有值，但不知何故只返回第一行值...

我试图添加dr2.NextResult（）;代码，但没有帮助

SqlCommand command = conn.CreateCommand();
command.CommandText = "select Test from PrescTest ";

conn.Open();
command.ExecuteNonQuery();

SqlDataReader dr2 = command.ExecuteReader();
try
{
    while (dr2.Read())
    {
        // get the results of column "Test"
        string Tests = (string)dr2["Test"].ToString();
        TextBox15.Text = Tests +" ";
    }
    conn.Close();
}
catch (SqlException sqlexception)
{
    Response.Write("ERROR ::" + sqlexception.Message);
}
catch (Exception ex)
{
    Response.Write("ERROR ::" + ex.Message);
}
finally
{
    conn.Close();
}

Answer 1

将为您分配值，并删除文本框的上一个值。试试这个：

while (dr2.Read())
{
    // get the results of column "Test"
    string Tests = dr2["Test"].ToString();
    TextBox15.Text += Tests +" ";
}

Answer 2

您正在覆盖来自数据库的值。参见下面的修订代码

  SqlCommand command = conn.CreateCommand();
    command.CommandText = "select Test from PrescTest ";

    conn.Open();

    //Nothing to execute so you can scrap this line
    //command.ExecuteNonQuery();

    SqlDataReader dr2 = command.ExecuteReader();
    try {
string Tests = "";

     if (dr2.HasRows) {

      while (dr2.Read()) {
       // get the results of column "Test"
       Tests += dr2["Test"].ToString() + " ";
      }

     }

      TextBox15.Text = Tests.Trim();
      conn.Close();

    } catch (SqlException sqlexception) {
     Response.Write("ERROR ::" + sqlexception.Message);
    } catch (Exception ex) {
     Response.Write("ERROR ::" + ex.Message);
    } finally {
     conn.Close();
    }

SqlDataReader为什么只返回第一行值？

2 个答案: