4. SQLserver连接数据库操作

SQLserver连接数据库操作

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

namespace Sql1
{
    class Program
    {
        //连接字符串--连接数据库用

        /// <summary>
        /// private 私有属性
        /// static 静态 应用程序打开, 运行时就在内存中
        /// readonly 只读类型
        /// @ 转义
        /// </summary>
        private static readonly string connString = @"Data Source=DESKTOP-9JEHCP6;Initial Catalog=StudentManage;User ID=sa;Password=sa;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False";
        static void Main(string[] args)
        {
            //定义SQL语句
            string sql = "select className from StudentClass where ClassName=N'小程序';";
            //连接SQL数据查询
            SqlConnection conn = new SqlConnection(connString);//连接数据库(连接数据库实例)
            SqlCommand cmd = new SqlCommand(sql, conn); // 发送sql命令
            conn.Open(); //打开数据库连接
            object result = cmd.ExecuteScalar();
            conn.Close();//关闭数据库
            //展示数据


            Console.WriteLine("班级名称" +result.ToString());
            Console.ReadKey();
        }
    }
}