Hướng dẫn cách truy vấn dữ liệu đơn đơn dòng dùng cách thông thường có dùng SqlDataReader và ExecuteReade

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace kncsdlhocba
{
    public partial class Truyvandulieudondong : Form
    {
        public Truyvandulieudondong()
        {
            InitializeComponent();
        }
        SqlConnection conec = null;
        string ketnoi = @”Server =DESKTOP-CR8PM8T\SQLEXPRESS; Database=CSDLSANPHAM ;      User ID=sa; pwd =123″;
        private void btnXem_Click(object sender, EventArgs e)
        {
            if (conec==null)
            {
                conec = new SqlConnection(ketnoi);
            }
            if (conec.State == ConnectionState.Closed)
            {
                conec.Open();
            }
           
            SqlCommand command = new SqlCommand();
            command.CommandType = CommandType.Text;
            command.CommandText = “select * from SanPham where ma=” + txtMamuontim.Text;
            command.Connection = conec;

            SqlDataReader reader = command.ExecuteReader();
            if (reader.Read())
            {
                txtMa.Text = reader.GetInt32(0) + “”;
                txtTen.Text = reader.GetString(1);
                txtGia.Text = reader.GetInt32(2).ToString();

            }
            reader.Close();      
        }

Cách kết dữ liệu sql server với c# truy vân dữ liệu có dùng SqlParameter

        private void txtpara_Click(object sender, EventArgs e)
        {
            if (conec==null)
            {
                conec = new SqlConnection(ketnoi);

            }
            if (conec.State== ConnectionState.Closed)
            {
                conec.Open();
            }
            SqlCommand command = new SqlCommand();
            command.CommandType = CommandType.Text;
            command.CommandText = ” select * from SanPham where ma=@ma”;
            command.Connection = conec;

            SqlParameter parama = new SqlParameter(“@ma”, SqlDbType.Int);
            parama.Value = txtMamuontim.Text;
            command.Parameters.Add(parama);

            SqlDataReader reader = command.ExecuteReader();
            if (reader.Read())
            {
                txtMa.Text = reader.GetInt32(0) + “”;
                txtTen.Text = reader.GetString(1);
                txtGia.Text = reader.GetInt32(2) + “”;
            }
            reader.Close();

        }

Video Hướng dẫn học lập trình c# cách truy vấn dữ liệu đơn dòng