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中有一个表。

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

现在，当用户选择One way relocation deal然后在db中时，将仅插入id,pickuplocation,returnlocation并且列所included location将为null。 并且当用户选择Regular deal ，列pickuplocation,returnlocation null，仅会设置列id and included location问题是我想使用其位置对整个数据进行排序。我尝试了此查询-

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

但这不会给出正确的结果，因为某些数据在所包含的位置中为空。我该如何对所有pickuplocation,returnlocation,exculded location排序

Answer 1

您需要IFNULL函数

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

我希望这将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=1或field2 >=1