在同一层次结构中的不同类之间的django ORM语法中使用UNION [英] Using UNION in django ORM syntax between different classes in the same hierarchy

问题描述

我需要实现类似于

 （SELECT table1。*，val = 2 FROM table1 INNER JOIN table2 ON table1。 id = table2.id WHERE some_condition）
 UNION 
（SELECT table1。*，val = 3 FROM table1 INNER JOIN table3 ON table1.id = table3.id WHERE some_condition）
  

或

 （SELECT val1， val2，val3，val = 2 FROM table2 WHERE some_condition）
 UNION 
（SELECT val1，val2，val3，val = 3 FROM table3 WHERE some_condition）
  pre> 
 
 
即可具有table1和table3从table1派生的类'table1'，'table2'和'table3'我需要使用附加字段选择所有这些。问题是我会预先避免使用raw sql查询，因为some_condition应该是可重用的。如果我尝试使用额外的，它会抱怨我使用 .extra 。
解决方案
 p>我决定移植到sqlalchemy  - 我的问题适合django，而且我对tg2感到高兴（这并不意味着django是不好的 - 它不太适合我的任务）。
 
I need to implement something like
 (SELECT table1.*, val=2 FROM table1 INNER JOIN table2 ON table1.id = table2.id WHERE some_condition)
 UNION
 (SELECT table1.*, val=3 FROM table1 INNER JOIN table3 ON table1.id = table3.id WHERE some_condition)
or
 (SELECT val1, val2, val3, val=2 FROM table2 WHERE some_condition)
 UNION
 (SELECT val1, val2, val3, val=3 FROM table3 WHERE some_condition)
I.e. having the class 'table1', 'table2' and 'table3' where table2 and table3 are derived from table1 I need to select all of them with additional field. The problem is that I'd prefere to avoid using raw sql queries as some_condition should be reusable. If I try to use extra it complains that I use .extra.
解决方案
I decided to port to sqlalchemy - my problem fit badly into django and I'm happier with tg2 (that said - it does not mean that django is bad - it is just not well suited for my task).

                        
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