如何在Kohana的查询生成器中使用ORDER BY和GROUP BY建立UNION查询? [英] How do I build a UNION query with ORDER BY and GROUP BY in Kohana's query builder?

问题描述

我正在尝试使用 Kohana的查询生成器构建UNION查询.一切正常，直到我添加了GROUP BY或ORDER BY子句.

I'm trying to build a UNION query using Kohana's query builder. Everything works fine until I add a GROUP BY or ORDER BY clause.

这是我正在使用的代码(简体):

Here is the code I'm using (simplified):

$query1 = DB::select('p.name')
    ->from(array('person', 'p'))
    ->where('p.organization', 'LIKE', 'foo%')
    ->limit(10);

$names = DB::select('sh.name')
    ->union($query1, FALSE)
    ->from(array('stakeholder', 'sh'))
    ->where('sh.organization', 'LIKE', 'foo%')
    ->group_by('name')
    ->order_by('name')
    ->limit(10)
    ->execute()
    ->as_array();

它不是在整个查询的末尾添加GROUP BY和ORDER BY，而是在第二个查询后立即添加.

Instead of adding the GROUP BY and ORDER BY at the end of the entire query, it's adding it immediately after the second query.

这是生成的SQL:

 SELECT sh.name FROM stakeholder AS sh WHERE sh.organization LIKE 'foo%' 
 GROUP BY name ORDER BY name LIMIT 10
 UNION
 SELECT p.name from person AS p WHERE p.organization LIKE 'foo%' LIMIT 10;

我想要的是:

 SELECT sh.name FROM stakeholder AS sh WHERE sh.organization LIKE 'foo%'
 UNION
 SELECT p.name from person AS p WHERE p.organization LIKE 'foo%'
 GROUP BY name ORDER BY name LIMIT 10;

推荐答案

此处的子句是从union()方法中设置的第一个查询中应用的，因此只需将它们放在相反的位置即可:

The clauses here are applied from the first query set up in the union() method, so just reverse where you're putting them:

$query1 = DB::select('p.name')
              ->from(array('person', 'p'))
              ->where('p.organization', 'LIKE', 'foo%')
              ->group_by('name')
              ->order_by('name')
              ->limit(10);

$names = DB::select('sh.name')
              ->union($query1, FALSE)
              ->from(array('stakeholder', 'sh'))
              ->where('sh.organization', 'LIKE', 'foo%')
              ->execute()
              ->as_array();

您也可以从$names中删除该多余的->limit(10)，因为它将被$query1中的那个忽略并取代.

You can also remove that superfluous ->limit(10) from $names since it will be ignored and superseded by the one in $query1.

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