我需要从另一个表中获取一个值，但可能有 5/6 个结果，我只需要显示最新的一个。我尝试了以下方法:

SELECT s.Mileage 
     , s.PurchasePrice 
     , v.make 
     , v.model 
     , v.vrm 
     , c.CleanLive  
  FROM StockBook s 
  LEFT  
  JOIN Vehicles v 
    ON v.VehicleID = s.VehicleID 
  LEFT  
  JOIN CapVals c 
    ON c.LeadID = (SELECT C1.CleanLive  
                   FROM CapVals C1 
                  WHERE s.LeadID = c.LeadID 
                  ORDER  
                     BY C1.Date  
                  LIMIT 1 
                )  
 ORDER  
    BY StockBookID 

它用作查询但不显示 CleanLive 值。

我在这里设置了一个示例数据集和 DB Fiddle:

CREATE TABLE `Vehicles` ( 
  `VehicleID` int(11) NOT NULL, 
  `vrm` varchar(15) NOT NULL, 
  `make` varchar(40) NOT NULL, 
  `model` varchar(40) NOT NULL 
) ENGINE=InnoDB DEFAULT CHARSET=latin1; 
 
CREATE TABLE `StockBook` ( 
  `StockBookID` int(11) NOT NULL, 
  `VehicleID` int(11) NOT NULL, 
  `LeadID` int(11) NOT NULL, 
  `Mileage` int(11) NOT NULL, 
  `PurchasePrice` decimal(15,2) NOT NULL 
) ENGINE=InnoDB DEFAULT CHARSET=latin1; 
 
CREATE TABLE `CapVals` ( 
  `CapValsID` int(11) NOT NULL, 
  `LeadID` int(11) DEFAULT NULL, 
  `CleanLive` int(11) DEFAULT NULL, 
  `Date` datetime DEFAULT NULL 
) ENGINE=InnoDB DEFAULT CHARSET=latin1; 
 
INSERT INTO `Vehicles` (`VehicleID`, `vrm`, `make`, `model`) VALUES 
(1, 'M900WRD', 'Vauxhall', 'Signum'); 
 
INSERT INTO `StockBook` (`StockBookID`, `LeadID`, `VehicleID`, `Mileage`, `PurchasePrice`) VALUES 
(1, 1, 1, 17000, 15000.00); 
 
INSERT INTO `CapVals` (`CapValsID`, `LeadID`, `CleanLive`, `Date`) VALUES 
(6455, 1, 1540, '2019-12-04 15:02:29'), 
(6456, 1, 1540, '2019-12-04 15:02:29'), 
(6457, 1, 1540, '2019-12-04 15:02:29'); 

https://www.db-fiddle.com/f/b4fQuMVpXHGxqgYJ4ia92w/4

请您参考如下方法:

你可以试试这个

SELECT Stock.Mileage, Stock.PurchasePrice, Vehi.make, Vehi.model, Vehi.vrm, 
(SELECT CleanLive from CapVals a WHERE a.LeadID = Stock.LeadID ORDER BY  DATE DESC LIMIT 1) AS CleanLive 
FROM StockBook Stock 
LEFT JOIN Vehicles Vehi 
ON Stock.VehicleID=Vehi.VehicleID 
ORDER BY StockBookID