c#数据库读取记录用到的方法

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通常有以下两种方式 SqlDataReader 和SqlDataAdapter|DataSet方式

SqlDataReader 方式使用方式如下：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;

namespace Login
{
class Program
{
static void Main(string[] args)
{
//新建一个数据库连接
using(SqlConnection conn = new SqlConnection(GetConnectString()))
{
conn.Open();//打开数据库
//Console.WriteLine("数据库打开成功!");
//创建数据库命令
SqlCommand cmd = conn.CreateCommand();
//创建查询语句
cmd.CommandText = "SELECT * FROM userinfo";
//从数据库中读取数据流存入reader中
SqlDataReader reader = cmd.ExecuteReader();

//从reader中读取下一行数据,如果没有数据,reader.Read()返回flase
while (reader.Read())
{
//reader.GetOrdinal("id")是得到ID所在列的index,
//reader.GetInt32(int n)这是将第n列的数据以Int32的格式返回
//reader.GetString(int n)这是将第n列的数据以string 格式返回
int id = reader.GetInt32(reader.GetOrdinal("id"));
string name = reader.GetString(reader.GetOrdinal("name"));
string pwd = reader.GetString(reader.GetOrdinal("password"));
int age = reader.GetInt32(reader.GetOrdinal("age"));
string sex = reader.GetString(reader.GetOrdinal("sex"));
string phone = reader.GetString(reader.GetOrdinal("phone"));
string address = reader.GetString(reader.GetOrdinal("Address"));

//格式输出数据
Console.Write("ID:{0},Name:{1},PWD:{2},Age:{3},Sex:{4},Phone{5},Address:{6}\n", id, name, pwd, age, sex, phone, address);
}
}
Console.ReadKey();
}
//得到一个数据库连接字符串
static string GetConnectString()
{
return "Data Source=(local);Initial Catalog=db1;Integrated Security=SSPI;";
}
}
}

SqlDataAdapter|DataSet 方式如下
加入为SQLSERVER数据库：
using System.Data.SqlClient;
using System.Data;
SqlConnection conn = new SqlConnection(connectionString);
SqlCommand cmd = new SqlCommand("secelt * from userinfo", conn);
SqlDataAdapter sda = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
sda.Fill(ds, "table");
return ds.Tables["table"];//返回的是一个DataTable