Guapo

CREATE TABLE `accounts` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` int(11) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE `customers` (
  `id` int(11) NOT NULL,
  `name` varchar(100) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE `transactions` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `customerId` int(11) DEFAULT NULL,
  `accountId` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

public class Transaction
{
    public int Id {get;set;}
    // other properties of transaction
    public decimal Total { get; set; }
    public int CustomerId { get; set; }
    public virtual Customer Customer { get; set; }
    public int AccountId { get; set; }
    public virtual Account Account { get; set; }
}

SELECT SUM(pd.max_sessions)
  FROM mybb_store_licenses l
LEFT JOIN mybb_store_packages p
       ON p.id = l.package_id
LEFT JOIN (SELECT *
             FROM mybb_store_package_details
		  ) pd
	   ON pd.package_id = p.id
    WHERE l.ts_expire >= NOW() AND
          pd.product_id = 34;

   SELECT ...
     FROM licenses l
LEFT JOIN package p
       ON p.package_id = l.package_id
LEFT JOIN package_details pd
       ON p.package_id = pd.package_details
    WHERE l.expire_data <= NOW() AND
          pd.in_use = 0 AND
          pd.product_id = XYZ