DataTable不从数据库中返回任何记录。为什么会这样呢？

-- 示例查询
SELECT * FROM YourTableName WHERE SomeCondition = 'SomeValue';

// 示例连接字符串（SQL Server）
string connectionString = "Server=your_server;Database=your_database;User Id=your_user;Password=your_password;";

using (SqlConnection connection = new SqlConnection(connectionString))
{
    try
    {
        connection.Open();
        Console.WriteLine("数据库连接成功！");
    }
    catch (Exception ex)
    {
        Console.WriteLine("数据库连接失败：" + ex.Message);
    }
}

using (SqlConnection connection = new SqlConnection(connectionString))
{
    string query = "SELECT * FROM YourTableName WHERE SomeCondition = @SomeValue";
    SqlCommand command = new SqlCommand(query, connection);
    command.Parameters.AddWithValue("@SomeValue", "SomeValue");

    try
    {
        connection.Open();
        using (SqlDataReader reader = command.ExecuteReader())
        {
            DataTable dataTable = new DataTable();
            dataTable.Load(reader);

            if (dataTable.Rows.Count == 0)
            {
                Console.WriteLine("没有找到符合条件的记录。");
            }
            else
            {
                Console.WriteLine("找到 " + dataTable.Rows.Count + " 条记录。");
            }
        }
    }
    catch (Exception ex)
    {
        Console.WriteLine("查询失败：" + ex.Message);
    }
}