ADO.NET数据查询方法

返回单一结果的查询方法

ExecuteScalar()方法的使用

 //编写连接字符串            string connString = "Server=.;DataBase=StudentManageDB;Uid=sa;Pwd=aaa999a9";            //创建连接对象            SqlConnection conn = new SqlConnection(connString);            //创建Command对象            string sql = "select Count(*) from Students";            SqlCommand cmd = new SqlCommand(sql, conn);            //打开连接执行查询            conn.Open();            object result = cmd.ExecuteScalar();            //关闭连接处理结果            conn.Close();            Console.WriteLine("学生总数"+result.ToString());            Console.ReadLine();

string connString = "Server=.;DataBase=StudentManageDB;Uid=sa;Pwd=aaa999a9";            SqlConnection conn = new SqlConnection(connString);            string sql = "select StudentName from Students where StudentId=" + 10073;            SqlCommand cmd = new SqlCommand(sql, conn);            conn.Open();            object result = cmd.ExecuteScalar();            conn.Close();            Console.WriteLine("学员姓名：{0}",result.ToString());            Console.ReadLine();

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返回一个结果集的查询方法

ExecuteReader()方法

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返回多个结果集的查询方法

NextResult()方法

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