C#与SQL Server数据库连接

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Data.SqlClient; namespace Demp13 { class Program { static void Main(string[] args) { //1.创建连接字符串
            string str = "server=.;database=MySchool;uid=sa;pwd=密码"; // string str = "Data Source=.;Initial Catalog=MySchool;User ID=sa;Password=accp"; //2.创建connection对象
            SqlConnection conn = new SqlConnection(str); try { //3.打开链接
 conn.Open(); Console.WriteLine("打开链接成功"); //4.准备sql语句，创建command对象，并执行sql语句
                Console.WriteLine("请输入用户名"); string name = Console.ReadLine(); Console.WriteLine("请输入密码"); string pwd = Console.ReadLine(); string sql = "select COUNT(*) from admin where loginId='"+name+"' and loginPwd='"+pwd+"'"; SqlCommand cmd = new SqlCommand(sql,conn); //5.执行sql语句，得到返回结果
               int r= Convert.ToInt32(cmd.ExecuteScalar()); if (r > 0) { Console.WriteLine("登陆成功"); } else { Console.WriteLine("登陆失败"); } } catch (Exception ex) { Console.WriteLine(ex.Message); } finally { //4.关闭链接
 conn.Close(); Console.WriteLine("关闭链接成功"); } } } }