winform数据库连接

using System;
using System.Data.SqlClient;
using System.Windows.Forms;

namespace WinformDatabaseConnectionDemo
{
    public partial class Form1 : Form
    {
        private string connectionString = "Server=your_server_address;Database=your_database_name;User Id=your_username;Password=your_password;";

        public Form1()
        {
            InitializeComponent();
        }

        private void btnQuery_Click(object sender, EventArgs e)
        {
            try
            {
                using (SqlConnection connection = new SqlConnection(connectionString))
                {
                    connection.Open();
                    string query = "SELECT * FROM your_table_name";
                    SqlCommand command = new SqlCommand(query, connection);
                    SqlDataReader reader = command.ExecuteReader();

                    while (reader.Read())
                    {
                        // 处理查询结果
                        MessageBox.Show(reader["your_column_name"].ToString());
                    }

                    reader.Close();
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show("连接数据库失败：" + ex.Message);
            }
        }
    }
}