1、使用SQL用户名、密码验证

Data Source = 服务器名；Initial Catalog = 数据库名；User ID = 用户名；Pwd = 密码（没有密码可以省略）

例如：

public string connString = "Data Source=xp;Initial Catalog=student;User ID = 123;Pwd = 123";

2、使用windows身份验证

Data Source = 服务器名；Initial Catalog = 数据库名；Integrated Security = TRUE(或者：SSPI)

例如：

public string connString = "Data Source=xp;Initial Catalog=student;Integrated Security=TRUE";

首先添加using指令

using System.Data;
using System.Data.SqlClient;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data;
using System.Data.SqlClient;
namespace sql_test
{
    class Program
    {
        static void Main(string[] args)
        {
            string connString = "Data Source=localhost;Initial Catalog=student;Integrated Security=TRUE";
            SqlConnection connection = new SqlConnection(connString);
            try
            {
                //打开数据库  
                connection.Open();
                //Console.WriteLine("打开数据库连接成功");
                string strqry="select * from student";
                SqlCommand cmd = new SqlCommand(strqry, connection);
                SqlDataReader dr;//创建DataReader对象  
                dr = cmd.ExecuteReader();//执行查询  
                //if (dr.HasRows)  //判断数据库中是否含有数据
                //{
                //    Console.WriteLine("含有数据");
                //}
                while (dr.Read())
                {
                    Console.Write(dr["id"].ToString()+",");
                    Console.Write(dr[1].ToString() + ",");
                    Console.Write(dr[2].ToString() + ",");
                    Console.WriteLine(dr[3].ToString());
                }
                dr.Close();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message.ToString());
            }  
           
            finally
            {
                //关闭数据库  
                connection.Close();
            }
            Console.ReadLine();
           
        }
    }
}

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版权声明：本文为CSDN博主「耳钉_梦」的原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/qq_37287697/article/details/79555457