crosstab()查询移位列

Question

我在postgres中使用交叉表函数。基本的SQL是：

select distinct  
       o_location,
       co_name,
       o_date,
       o_ndate,
       o_day,
       o_hour,
       o_type
  from outputs_txt
  left join courses on o_course = co_foreign
  left join locations on o_location = l_code
 where o_date = '2011-10-10' 
 order by o_hour

我的交叉表查询是

SELECT *
  FROM crosstab(
'SELECT DISTINCT
        COALESCE(o_location, '''')
       ,o_hour AS hour
       ,c.co_name
   FROM outputs_txt AS d
   LEFT JOIN courses AS c 
     on o_course = c.co_foreign
   LEFT JOIN locations as a 
     on o_location = a.l_code
  WHERE d.o_date = ''2011-10-10'''
)
AS ct(
 o_location varchar
,hour_0  varchar
,hour_1  varchar
,hour_2  varchar
,hour_3  varchar
,hour_4  varchar
,hour_5  varchar
,hour_6  varchar
,hour_7  varchar
,hour_8  varchar
,hour_9  varchar
,hour_10 varchar
,hour_11 varchar
,hour_12 varchar
,hour_13 varchar
,hour_14 varchar
,hour_15 varchar
,hour_16 varchar
,hour_17 varchar)

问题是结果都被左移了。

例如，如果某个位置的课程应该显示在hour_8上，它就会显示在hour_0中。

这适用于所有地点的所有课程。它们都左对齐。

我哪里做错了？

Answer 1

由于没有样本数据，我只能猜测。下面是给我留下深刻印象的：

交叉表函数中没有ORDER BY。我添加了一个：

SELECT *
  FROM crosstab(
'SELECT DISTINCT
        COALESCE(o_location, '''')
       ,o_hour AS hour
       ,c.co_name
   FROM outputs_txt AS d
   LEFT JOIN courses AS c    ON o_course = c.co_foreign
   LEFT JOIN locations as a  ON o_location = a.l_code
  WHERE d.o_date = ''2011-10-10''
  ORDER BY 1,2'
)
AS ct(
 o_location varchar
,hour_0  varchar
,hour_1  varchar
,hour_2  varchar
,hour_3  varchar
,hour_4  varchar
,hour_5  varchar
,hour_6  varchar
,hour_7  varchar
,hour_8  varchar
,hour_9  varchar
,hour_10 varchar
,hour_11 varchar
,hour_12 varchar
,hour_13 varchar
,hour_14 varchar
,hour_15 varchar
,hour_16 varchar
,hour_17 varchar)

如果你想先订购hour_0，你必须按o_hour订购。我引用manual on crosstab functions的话

实际上，SQL查询应始终指定ORDER BY 1,2以确保输入行的顺序正确，也就是说，具有相同row_name的值被组合在一起并在行中正确排序。