ADO增删查改
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ADO
{
class Program
{
//1、连接字符串
private static string connectionString = "server=localhost;database=MyScool;uid=sa;pwd=123";
static void Main(string[] args)
{
#region 创建数据库的连接
//2、创建数据库的连接
//①
//SqlConnection conn = new SqlConnection(connectionString);
// //②
////SqlConnection conn = new SqlConnection();
////conn.ConnectionString = connectionString;
////3、打开数据库的连接
//conn.Open();
//Console.WriteLine(conn);
////4、关闭当前数据库连接
//conn.Close();
////5、销毁当前数据库连接
//conn.Dispose();
//Console.WriteLine(conn);
//Console.ReadKey();
#endregion
#region 执行SQL的 聚合函数
////1 创建数据库连接对象
//SqlConnection conn = new SqlConnection(connectionString);
////2 打开数据库的连接
//conn.Open();
////3 创建command对象
//SqlCommand command = new SqlCommand("select COUNT(*) from t_Student", conn);
////4 执行SQL语句
//int count = int.Parse(command.ExecuteScalar().ToString());
//Console.WriteLine("一共有{0}条记录",count);
////5 关闭数据库的连接
//conn.Close();
////6 销毁数据库连接
//conn.Dispose();
//Console.ReadKey();
#endregion
#region 执行SQL的 增加
//using (SqlConnection conn = new SqlConnection(connectionString))
//{
// conn.Open();
// //sql语句的拼接
// string sql = "insert into t_Student(Scode,SName,SAddress,SGrade,SEmail,SSex) values(NEWID(),@SName,@SAddress,@SGrade,@SEmail,@SSex)";
// SqlParameter sqlpara1 = new SqlParameter("@SName","新插入的信息");
// SqlParameter sqlpara2 = new SqlParameter("@SAddress", "长沙");
// SqlParameter sqlpara3 = new SqlParameter("@SGrade", "7");
// SqlParameter sqlpara4 = new SqlParameter("@SEmail", "234@123.com");
// SqlParameter sqlpara5 = new SqlParameter("@SSex", "女");
// SqlCommand command = new SqlCommand(sql,conn);
// //对@的参数进行赋值操作
// command.Parameters.Add(sqlpara1);
// command.Parameters.Add(sqlpara2);
// command.Parameters.Add(sqlpara3);
// command.Parameters.Add(sqlpara4);
// command.Parameters.Add(sqlpara5);
// //返回影响行数
// int index = command.ExecuteNonQuery();
// if (index > 0)
// {
// Console.WriteLine("操作成功!!!");
// }
// else
// {
// Console.WriteLine("操作失败!!!");
// }
// Console.ReadKey();
//}
#endregion
#region 执行SQL的 修改
//using (SqlConnection conn = new SqlConnection(connectionString))
//{
// conn.Open();
// SqlCommand command = new SqlCommand("update t_Student set SName=@SName,SAddress=@SAddress,SGrade=@SGrade,SEmail=@SEmail,SSex=@SSex where Scode=@Scode",conn);
// command.Parameters.Add("@SName", "修改的名字");
// command.Parameters.Add("@SAddress", "修改后的地址");
// command.Parameters.Add("@SGrade", 10);
// command.Parameters.Add("@SEmail", "12345678@qq.com");
// command.Parameters.Add("@SSex", "男");
// command.Parameters.Add("@Scode", "F70325E1-50FF-4F17-BDA5-D2FAD15DF4AE");
// int index = command.ExecuteNonQuery();
// if (index > 0)
// {
// Console.WriteLine("操作成功!!!");
// }
// else
// {
// Console.WriteLine("操作失败!!!");
// }
// Console.ReadKey();
//}
#endregion
#region 执行SQL的 删除
//using(SqlConnection conn = new SqlConnection(connectionString))
//{
// conn.Open();
// SqlCommand command = new SqlCommand("delete from t_Student where SCode=@SCode", conn);
// command.Parameters.Add("@SCode","F70325E1-50FF-4F17-BDA5-D2FAD15DF4AE");
// int index = command.ExecuteNonQuery();
// Console.WriteLine(index>0?"操作成功!!!":"操作失败!!!");
// Console.ReadKey();
//}
#endregion
#region datareader 生成一个List的 泛型集合中会被使用到
//-----①
//SqlDataReader sdr = null;
//using (SqlConnection conn = new SqlConnection(connectionString))
//{
// conn.Open();
// SqlCommand command = new SqlCommand("select * from t_student",conn);
// sdr = command.ExecuteReader();
// if (sdr.HasRows)
// {
// while (sdr.Read())
// {
// //获取当前流的数据
// string outStr = string.Format("编号:{0},姓名:{1},地址:{2},性别:{3}", sdr["Scode"], sdr["Sname"], sdr["saddress"], sdr["ssex"]);
// Console.WriteLine(outStr);
// }
// }
//}
//Console.WriteLine(sdr.IsClosed);
//Console.ReadKey();
//-----②
//using (SqlConnection conn = new SqlConnection(connectionString))
//{
// conn.Open();
// SqlCommand command = new SqlCommand("select * from t_student", conn);
// //关闭数据库的连接以后 在关闭datareader
// using (SqlDataReader sdr = command.ExecuteReader(CommandBehavior.CloseConnection))
// {
// if (sdr.HasRows)
// {
// while (sdr.Read())
// {
// //获取当前流的数据
// string outStr = string.Format("编号:{0},姓名:{1},地址:{2},性别:{3}", sdr["Scode"], sdr["Sname"], sdr["saddress"], sdr["ssex"]);
// Console.WriteLine(outStr);
// }
// }
// }
//}
//Console.ReadKey();
#endregion
#region dataset
//using(SqlConnection conn = new SqlConnection(connectionString))
//{
// conn.Open();
// SqlDataAdapter sda = new SqlDataAdapter("select * from t_student", conn);
// DataSet ds = new DataSet();
// sda.Fill(ds);
// Console.WriteLine(ds.Tables[0].TableName);
//}
//Console.ReadKey();
#endregion
#region datatable
//using(SqlConnection conn = new SqlConnection(connectionString))
//{
// conn.Open();
// SqlDataAdapter sdr = new SqlDataAdapter("select * from t_student", conn);
// DataSet ds = new DataSet();
// sdr.Fill(ds);
// DataTable dt = ds.Tables[0];
// //-- 1 for
// //for (int i = 0; i < dt.Rows.Count; i++)
// //{
// // //---①
// // //DataRow dr = dt.Rows[i];
// // //Console.WriteLine(dr["scode"]+"............."+dr["sname"]);
// // //---②
// // Console.WriteLine(dt.Rows[i]["Scode"]+"........."+dt.Rows[i]["sname"]);
// //}
// //-- 2 foreach
// foreach (DataRow item in dt.Rows)
// {
// Console.WriteLine(item["Scode"]+"....."+item["sname"]);
// }
//}
//Console.ReadKey();
#endregion
#region 自己创建一个datatable 的数据库
//DataTable dt = new DataTable();
//DataColumn dcIndex = new DataColumn("index", Type.GetType("System.Int32"));
//dt.Columns.Add(dcIndex);
//for (int i = 0; i < 100; i++)
//{
// DataRow dr = dt.NewRow();
// dr["index"] = i;
// //dr[dcIndex] = i;
// dt.Rows.Add(dr);
//}
//Console.WriteLine(dt.Rows.Count);
//Console.ReadKey();
#endregion
}
}
}