'union'或附近的SQL语法错误

Question

我有一个小查询，并在其旁边放了一个联合查询。但是，联合中存在语法错误。

Select <column1>
      ,<column2>
From <Table1> 
<Some joins in there>
Where <conditions>
group by <column2>
order by <column2>

union

select <column2>
      ,<column3>
      ,<column4>
From <Table2>
<Some more joins here>
Where <conditions>
group by <column2>
order by <column2>

这是我收到的错误

ERROR: Syntax error at or near 'union'

Answer 1

我知道出了什么问题。您必须在查询的末尾且仅在末尾下订单。它给了我一个错误，因为它认为查询已结束。

Select <column1>
      ,<column2>
      ,<aggregate column3>
From <Table1> 
<Some joins in there>
Where <conditions>
group by <column2>, <column1>

union

select <column2>
      ,<column3>
      ,<aggregate column4>
From <Table2>
<Some more joins here>
Where <conditions>
group by <column2>, <column3>
order by <column2>

做到了。