sql - 我该如何编写这个 MySQL 查询来获取正确的信息？ (子查询，多个子查询)

Question

这是我正在处理的查询:

SELECT `unitid`, `name` FROM apartmentunits
WHERE aptid = (
    SELECT `aptid` FROM rentconditionsmap WHERE rentcondid = 1 AND condnum = 1
)

我无法弄清楚如何编写此代码以添加更多租金条件限制器以进一步过滤此列表。

SELECT `aptid` FROM rentconditionsmap WHERE rentcondid = 1 AND condnum = 1

数据:

CREATE TABLE IF NOT EXISTS `rentconditionsmap` (
   `rcid` bigint(10) unsigned NOT NULL AUTO_INCREMENT, 
   `rentcondid` int(3) unsigned NOT NULL, 
   `condnum` tinyint(3) unsigned NOT NULL, 
   `aptid` bigint(10) unsigned DEFAULT NULL, 
   PRIMARY KEY (`rcid`), KEY `aptid` (`aptid`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=18 ;

INSERT INTO `rentconditionsmap` 
  (`rcid`, `rentcondid`, `condnum`, `aptid`) 
VALUES 
  (1, 1, 1, 1), 
  (2, 2, 1, 1), 
  (3, 3, 0, 1), 
  (4, 4, 1, 1), 
  (5, 8, 0, 1);

CREATE TABLE IF NOT EXISTS `apartmentunits` (
  `unitid` bigint(10) NOT NULL AUTO_INCREMENT, 
  `aptid` bigint(10) NOT NULL, 
  `name` varchar(6) NOT NULL, 
  `verified` tinyint(1) NOT NULL DEFAULT '0', 
  `rentcost` int(4) unsigned DEFAULT NULL, 
  `forrent` tinyint(1) NOT NULL DEFAULT '0', 
  `unittypekey` varchar(2) DEFAULT NULL, 
  `sqft` smallint(6) DEFAULT NULL, 
  PRIMARY KEY (`unitid`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=121 ;

INSERT INTO `apartmentunits` 
  (`unitid`, `aptid`, `name`, `verified`, `rentcost`, `forrent`, `unittypekey`, `sqft`) 
VALUES 
  (1, 1, '3', 1, 540, 0, '2B', NULL), 
  (2, 1, '5', 1, NULL, 0, '2B', NULL), 
  (3, 1, '7', 1, NULL, 0, '2B', NULL), 
  (53, 1, '1', 1, NULL, 0, '2B', NULL), 
  (54, 1, '2', 1, NULL, 0, '2B', NULL), 
  (55, 1, '4', 1, 570, 0, '2B', NULL), 
  (56, 1, '6', 1, NULL, 0, '2B', NULL), 
  (57, 1, '8', 1, NULL, 0, '2B', NULL), 
  (58, 1, '9', 1, NULL, 0, '2B', NULL), 
  (59, 1, '10', 1, NULL, 0, '2B', NULL), 
  (60, 1, '11', 1, NULL, 0, '2B', NULL);

Answer 1

正如 Eric J 在评论中所说:

Try changing = to IN

SELECT `unitid`, `name` FROM apartmentunits
WHERE `aptid` IN (
    SELECT `aptid` FROM rentconditionsmap WHERE rentcondid = 1 AND condnum = 1
)