Question

SqlDataReader reader = cmd.ExecuteReader();这句话出现异常，怎么办啊？

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;

namespace WindowsFormsApplication1
{
class ADOText
{
public string TextDB()
{
//步骤一，连接数据库 需要创建连接对象
string connString = @"Data Source=.\SQLEXPRESS;Initial Catalog=master;Integrated Security=True";
SqlConnection conn = new SqlConnection(connString);
conn.Open(); //打开数据库

//步骤二：创建执行对象及SQL语句
string sql = "select * from 2b";//要执行的SQL语句
SqlCommand cmd = new SqlCommand(sql, conn);

//步骤三：创建数据读取对象，循环读取数据
SqlDataReader reader = cmd.ExecuteReader();
string content="";
while (reader.Read())
{
content += reader["name"].ToString();

}
//步骤四：关闭数据库连接
conn.Close();
return content;

}
}
}

Answer 1

string sql = "select * from 2b";//要执行的SQL语句
表名最好不要用数字开头，可以写成string sql = "select * from [2b]";