JSON聚合解决方案:

CREATE TEMP TABLE t (
  section   text
, status    text
, ct        integer  -- don't use "count" as column name.
);

INSERT INTO t VALUES 
  ('A', 'Active', 1), ('A', 'Inactive', 2)
, ('B', 'Active', 4), ('B', 'Inactive', 5)
                   , ('C', 'Inactive', 7); 


SELECT section,
       (obj ->> 'Active')::int AS active,
       (obj ->> 'Inactive')::int AS inactive
FROM (SELECT section, json_object_agg(status,ct) AS obj
      FROM t
      GROUP BY section
     )X

Crosstab函数在tablefunc扩展名下可用。您必须为数据库创建此扩展一次。

创建扩展表

你可以使用下面的代码来创建数据透视表:

create table test_Crosstab( section text,
status text,
count numeric)

insert into test_Crosstab values ( 'A','Active',1)
                ,( 'A','Inactive',2)
                ,( 'B','Active',4)
                ,( 'B','Inactive',5)

select * from crosstab(
    'select section
    ,status
    ,count
    from test_crosstab'
    )as ctab ("Section" text,"Active" numeric,"Inactive" numeric)

抱歉，这不是完整的，因为我不能在这里测试它，但它可能会让你在正确的方向。我翻译了一些类似的问题:

select mt.section, mt1.count as Active, mt2.count as Inactive
from mytable mt
left join (select section, count from mytable where status='Active')mt1
on mt.section = mt1.section
left join (select section, count from mytable where status='Inactive')mt2
on mt.section = mt2.section
group by mt.section,
         mt1.count,
         mt2.count
order by mt.section asc;

我正在工作的代码是:

select m.typeID, m1.highBid, m2.lowAsk, m1.highBid - m2.lowAsk as diff, 100*(m1.highBid - m2.lowAsk)/m2.lowAsk as diffPercent
from mktTrades m
   left join (select typeID,MAX(price) as highBid from mktTrades where bid=1 group by typeID)m1
   on m.typeID = m1.typeID
   left join (select typeID,MIN(price) as lowAsk  from mktTrades where bid=0 group by typeID)m2
   on m1.typeID = m2.typeID
group by m.typeID, 
         m1.highBid, 
         m2.lowAsk
order by diffPercent desc;

它将返回一个类型id，最高出价和最低要价以及两者之间的差值(正差值意味着可以以低于出售的价格购买某样东西)。

SELECT section,
       SUM(CASE status WHEN 'Active' THEN count ELSE 0 END) AS active, --here you pivot each status value as a separate column explicitly
       SUM(CASE status WHEN 'Inactive' THEN count ELSE 0 END) AS inactive --here you pivot each status  value as a separate column explicitly

FROM t
GROUP BY section

我设计了一种不同的动态方法，它采用了动态rec. type(一个临时表，通过匿名过程构建)& JSON。这对于不能安装tablefunc/crosstab扩展，但仍然可以创建临时表或运行anon. proc's的最终用户可能很有用。

这个例子假设所有的xtab列都是相同的类型(INTEGER)，但是列的#是数据驱动和可变的。也就是说，JSON聚合函数允许混合数据类型，因此通过使用嵌入式复合(混合)类型有创新的潜力。

如果您想在JSON记录集函数中静态地定义rec.类型(通过发出复合类型的嵌套select)，那么它的真正内容可以减少到一个步骤。

dbfiddle.uk

https://dbfiddle.uk/N1EzugHk

JSON聚合解决方案:

CREATE TEMP TABLE t (
  section   text
, status    text
, ct        integer  -- don't use "count" as column name.
);

INSERT INTO t VALUES 
  ('A', 'Active', 1), ('A', 'Inactive', 2)
, ('B', 'Active', 4), ('B', 'Inactive', 5)
                   , ('C', 'Inactive', 7); 


SELECT section,
       (obj ->> 'Active')::int AS active,
       (obj ->> 'Inactive')::int AS inactive
FROM (SELECT section, json_object_agg(status,ct) AS obj
      FROM t
      GROUP BY section
     )X