Question

我有一个独特的情况。我有一个函数可以动态生成SQl并在mySQL数据库上运行它。它通过ste构建SQL查询步骤，并且非常复杂。

WHERE子句中最多可以包含40个不同的AND。例如。

SELECT * FROM TableX   //yea I know  don't search for * ...  trying to save typing on stack.
WHERE  Size = 'Large'
AND color= 'blue'
AND smell = 'stinky'
AND ugly = 'no'
AND brand = 'United'
etc...

在结束时，它会输出一行ORDER BY。如：

ORDER BY brand

我的挑战是我只能使用ORDER BY 某些字符串进行订购。如果我想从主表中订购数据，这可以正常工作。但是，如果它出自相关表格，我该怎么办？

说我有以下架构：

CREATE  TABLE `Trucks` (
  `ID` INT NOT NULL AUTO_INCREMENT ,
  `Make` VARCHAR(45) NULL ,
  `Current_PartList_ID` INT NULL ,
  PRIMARY KEY (`ID`) );

INSERT INTO `Trucks` (`Make`, `Current_PartList_ID`) VALUES ('Volvo', '1');
INSERT INTO `Trucks` (`Make`, `Current_PartList_ID`) VALUES ('Volvo', '2');
INSERT INTO `Trucks` (`Make`, `Current_PartList_ID`) VALUES ('Mac', '3');
INSERT INTO `Trucks` (`Make`, `Current_PartList_ID`) VALUES ('Mac', '5');
INSERT INTO `Trucks` (`Make`, `Current_PartList_ID`) VALUES ('Daihatsu', '8');
INSERT INTO `Trucks` (`Make`, `Current_PartList_ID`) VALUES ('Volvo', '4');


CREATE  TABLE `Parts_lists` (
  `ID` INT NOT NULL AUTO_INCREMENT ,
  `Carb_Model` VARCHAR(45) NULL ,
  `Carb_date` DATE NULL ,
  `Tire_type` VARCHAR(45) NULL ,
  `Tire_date` DATE NULL ,
  PRIMARY KEY (`ID`) );

INSERT INTO `Parts_lists` (`Carb_Model`, `Carb_date`, `Tire_type`, `Tire_date`) VALUES ('Hirsch', '2012-12-19', 'Toyo', '2013-01-01');
INSERT INTO `Parts_lists` (`Carb_Model`, `Carb_date`, `Tire_type`, `Tire_date`) VALUES ('HIrsch', '2013-02-14', 'Goodyear', '2011-03-16');
INSERT INTO `Parts_lists` (`Carb_Model`, `Carb_date`, `Tire_type`, `Tire_date`) VALUES ('Bosch', '2011-11-04', 'Toyo', '2013-01-01');
INSERT INTO `Parts_lists` (`Carb_Model`, `Carb_date`, `Tire_type`, `Tire_date`) VALUES ('Miller', '2009-10-11', 'Toyo', '2010-04-17');
INSERT INTO `Parts_lists` (`Carb_Model`, `Carb_date`, `Tire_type`, `Tire_date`) VALUES ('Bosch', '2011-01-07', 'Goodyear', '2013-01-06');
INSERT INTO `Parts_lists` (`Carb_Model`, `Carb_date`, `Tire_type`, `Tire_date`) VALUES ('Bosch', '2012-09-16', 'Lamb', '2012-06-25');
INSERT INTO `Parts_lists` (`Carb_Model`, `Carb_date`, `Tire_type`, `Tire_date`) VALUES ('Miller', '2011-07-22', 'Unknown', '2012-04-07');
INSERT INTO `Parts_lists` (`Carb_Model`, `Carb_date`, `Tire_type`, `Tire_date`) VALUES ('Davis', '2009-03-09', 'Hawking', '2012-06-16');
INSERT INTO `Parts_lists` (`Carb_Model`, `Carb_date`, `Tire_type`, `Tire_date`) VALUES ('Sanno', '2010-01-07', 'Goodyear', '2009-07-16');
INSERT INTO `Parts_lists` (`Carb_Model`, `Carb_date`, `Tire_type`, `Tire_date`) VALUES ('Thrust', '2012-11-11', 'Lamb', '2004-04-08');

我想得到：

SELECT * FROM Trucks WHERE Make ='volvo'ORDER BY（* Parts_List.Carb_date *）

因此给我以下选择

ID    Make      (why)
6     Volvo     (Because the Carb_date is 2009-10-11)
1     Volvo     (Because the Carb_date is 2012-12-19)
2     Volvo     (Because the Carb_date is 2013-02-14)

非常清楚：我坚持：以下文字（我根本无法编辑它：没有完全重写一个古老丑陋的应用程序）：

SELECT * FROM Trucks WHERE Make = 'volvo' ORDER BY

我需要XXXXXXX的字符串

SELECT * FROM Trucks WHERE Make = 'volvo' ORDER BY   XXXXXXX

Answer 1

这可以作为ORDER BY字符串：

(SELECT Carb_date FROM Parts_lists WHERE ID = Trucks.Current_PartList_ID)

在没有第二表的JOIN的情况下订购

1 个答案: