PostgreSQL查询不一致

我正在尝试执行此SQL命令:

SELECT page.page_namespace, pagelinks.pl_namespace, COUNT(*) 
    FROM page, pagelinks
    WHERE 
        (page.page_namespace <=3 OR page.page_namespace = 12 
            OR page.page_namespace = 13
        ) 
        AND 
        (pagelinks.pl_namespace <=3 OR pagelinks.pl_namespace = 12 
            OR pagelinks.pl_namespace = 13
        )
        AND 
        (page.page_is_redirect = 0)
        AND 
        pagelinks.pl_from = page.page_id 
    GROUP BY (page.page_namespace, pagelinks.pl_namespace) 
; 

当我这样做时,我收到以下错误:

    ERROR:  could not identify an ordering operator for type record
    HINT:  Use an explicit ordering operator or modify the query.

    ********** Error **********

    ERROR: could not identify an ordering operator for type record
    SQL state: 42883
    Hint: Use an explicit ordering operator or modify the query.

我已经尝试添加:ORDER BY(page.page_namespace,pagelinks.pl_namespace)ASC到查询结束但没有成功.

更新:

我也试过这个:

SELECT page.page_namespace, pagelinks.pl_namespace, COUNT(*) 
    FROM page, pagelinks
    WHERE pagelinks.pl_from = page.page_id 
    GROUP BY (page.page_namespace, pagelinks.pl_namespace) 
; 

但我仍然得到同样的错误.

谢谢

我没有检查过任何文档,但你GROUP BY在括号中表达的事实对我来说并不常见.如果你不在这里使用括号会怎么样？