如何使用C＃从asp.net的sql表中读取每行和每列中的数据？

Sql数据库是StudentInfo ，表名是Registration

ID----------Name---------------Email---------------------------PhoneNo 1 Munasunghe [e-mail] 0717069425 2 Liyanarachchi [e-mail] 0756706352 

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 protected void Page_Load(object sender, EventArgs e) { string query = "select ID, Name, Email, PhoneNo from Registration"; SqlCommand cmd1 = new SqlCommand(query); DataTable dt1 = GetData(cmd1); int rowcount = dt1.Rows.Count; /* I want to read data in each row step by step and assign to variables*/ } 

函数GetData用于从数据库中获取数据。

  private DataTable GetData(SqlCommand cmd) { DataTable dt = new DataTable(); String strConnString = System.Configuration.ConfigurationManager.ConnectionStrings["conString"].ConnectionString; SqlConnection con = new SqlConnection(strConnString); SqlDataAdapter sda = new SqlDataAdapter(); cmd.CommandType = CommandType.Text; cmd.Connection = con; try { con.Open(); sda.SelectCommand = cmd; sda.Fill(dt); return dt; } catch { return null; } finally { con.Close(); sda.Dispose(); con.Dispose(); } } 

ID是Primarykey。

结果应该是（名称，电子邮件，电话号码是变量和1,2，…是ID值）

 Name[1]=Munasunghe Name[2]=Liyanarachchi Email[1]=[e-mail] Email[2]=[e-mail] Phone No[1]=0717069425 Phone No[2]=0756706352 

Answer 1

我会说你首先创建一个用于存储数据的新类（如StudentInfo）

 public class StudentInfo { public StudentInfo(int ID, string Name, string Email, string PhoneNo) { this.ID = ID; this.Name = Name; this.Email = Email; this.PhoneNo = PhoneNo; } public int ID { get; set; } public string Name { get; set; } public string Email { get; set; } public string PhoneNo { get; set; } } 

然后使用此函数返回一个StudentInfo类的List

 public List GetData() { List data = new List(); SqlConnection con = new SqlConnection("Your connection string"); SqlCommand command = new SqlCommand("SELECT * FROM [Registration]", con); con.Open(); SqlDataReader sdr = command.ExecuteReader(); while(sdr.Read()) { data.Add((int)sdr["ID"], (string)sdr["Name"], (string)sdr["Email"], (string)sdr["PhoneNo"]); } con.Close(); return data; } 

然后你像这样使用它：

 List info = GetData(); foreach(StudentInfo si in info) { Response.Write("
ID is " + si.ID + "
StudentName is " + si.Name + "
"); } 

要更新值，请执行以下操作：

 public void SetValue(int StudentID, String NewName, String NewEmail, String NewPhone) { SqlConnection con = new SqlConnection("Your connection string"); SqlCommand command = new SqlCommand("UPDATE [Registration] SET [Name]='" + NewName + "', [Email]='" + NewEmail + "', [PhoneNo]='" + NewPhone + "' WHERE [ID]=" + StudentID + "", con); con.Open(); command.ExecuteNonQuery(); con.close(); } 

我建议你阅读一些关于sql的文章