php - 在 MYSQL 中使用 ORDER BY 子句对数据进行排序

Question

我的表格中有两种类型的交易1)One way relocation deal and 2)Regular deal。我的 db -Vehicles 中有一张桌子。

vehicles table
=====================================================
id, pickuplocation, returnlocation, included location

现在，当用户One way relocation deal在 db 中选择 then 时，只会id,pickuplocation,returnlocation插入并且该列included location将为空。当用户选择时Regular deal，该列将为pickuplocation,returnlocation空，只有列id and included location将设置。问题是我想使用他们的位置对整个数据进行排序。我试过这个查询 -

SELECT * 
FROM vehicles 
where 1=1 
ORDER BY pickuplocation ASC,returnlocation ASC

但它不会给出正确的结果，因为某些数据在包含的位置为空。我如何对所有数据进行排序pickuplocation,returnlocation,exculded location

Answer 1

你想要的IFNULL功能

尝试排序

 IFNULL(returnlocation, includedlocation)

Answer 2

得到了解决方案。我使用了这个查询

(SELECT id,pickuplocation,returnlocation,deal_type FROM `vehicles` where deal_type = 1)

UNION

(SELECT id,included_location,excluded_location,deal_type FROM `vehicles`  where deal_type = 2)

order by pickuplocation,returnlocation

我希望这对将来可能遇到类似问题的人有所帮助。

Answer 3

SELECT * 
FROM vehicles 
where 1=1 AND ($condition) 
ORDER BY pickuplocation ASC,returnlocation ASC

假设$condition将类似于field01=1ORfield2 >=1