从sql表中检索数据到combobox中的datagridview

// 连接数据库
SqlConnection connection = new SqlConnection("YourConnectionString");
connection.Open();

// 编写SQL查询语句
string sqlQuery = "SELECT Column1, Column2 FROM YourTable";

// 执行查询语句
SqlCommand command = new SqlCommand(sqlQuery, connection);
SqlDataReader reader = command.ExecuteReader();

// 绑定数据到ComboBox
comboBox.DataSource = reader;
comboBox.DisplayMember = "Column1";
comboBox.ValueMember = "Column2";

// 处理选择事件
comboBox.SelectedIndexChanged += (sender, e) =>
{
    // 获取选择的项的值
    string selectedValue = comboBox.SelectedValue.ToString();

    // 根据选择的项检索数据到DataGridView
    string dataQuery = $"SELECT * FROM YourTable WHERE Column2 = '{selectedValue}'";
    SqlCommand dataCommand = new SqlCommand(dataQuery, connection);
    SqlDataAdapter adapter = new SqlDataAdapter(dataCommand);
    DataTable dataTable = new DataTable();
    adapter.Fill(dataTable);

    // 绑定数据到DataGridView
    dataGridView.DataSource = dataTable;
};

// 关闭数据库连接
connection.Close();