ado.net入门

 ???????????//1.0连接字符串 ???????????string conStr = "Data Source=.;Initial Catalog=test;User ID=sa;Password=‘qwertyu‘"; ???????????//2.0返回第行第一列结果 ???????????using (SqlConnection conn = new SqlConnection(conStr)) ???????????{ ???????????????string sqlStr = @"select count(1) from sys_users where deleteflag =0"; ???????????????conn.Open(); ???????????????SqlCommand command = new SqlCommand(sqlStr, conn); ???????????????int result = Convert.ToInt32(command.ExecuteScalar()); ???????????} ???????????//3.0返回第行第一列结果 ???????????using (SqlConnection conn = new SqlConnection(conStr)) ???????????{ ???????????????string sqlStr = @"insert into sys_users (ID,Name,Age) values(100,‘12334efdgdfg‘,13)"; ???????????????//string sqlStr = @"insert into sys_users values(100,‘12334efdgdfg‘,13,0)"; ???????????????//update Sys_Users set Name=‘pppppppppp‘ where ID=1 ???????????????conn.Open(); ???????????????SqlCommand command = new SqlCommand(sqlStr, conn); ???????????????int result = Convert.ToInt32(command.ExecuteNonQuery()); ???????????} ???????????//4.0返回结果集 ???????????SqlDataAdapter da = new SqlDataAdapter("select name from Sys_Users ?where DeleteFlag=0;select age from Sys_Users ?where DeleteFlag=0", conStr); ???????????DataSet ds = new DataSet(); ???????????da.Fill(ds);