pgsql不固定列数的行转列怎么写sql

pgsql不固定列数的行转列怎么写sql
近期遇到一个需求，需要根据物品类型按照日期进行行转列，因为日期不确定，所以行转后的列也是不确定的，这种sql怎么写？
转换前的数据

转换后想要的数据

用pivot做

这种用高级语言一个循环搞定的事情，就不要折腾sql了

• 这个问题的回答你可以参考下: https://ask.csdn.net/questions/7660204
• 除此之外, 这篇博客: pgsql 常用查询汇总(查询数据表字段)中的 6.查询正在执行的sql 部分也许能够解决你的问题, 你可以仔细阅读以下内容或跳转源博客中阅读:
  

• 
  SELECT
  pid,
  	datname,
  	usename,
  	client_addr,
  	application_name,
  	STATE,
  	backend_start,
  	xact_start,
  	xact_stay,
  	query_start,
  	query_stay,
  	REPLACE ( query, chr( 10 ), ' ' ) AS query 
  FROM
  	(
  SELECT
  pid,
  	pgsa.datname AS datname,
  	pgsa.usename AS usename,
  	pgsa.client_addr client_addr,
  	pgsa.application_name AS application_name,
  	pgsa.STATE AS STATE,
  	pgsa.backend_start AS backend_start,
  	pgsa.xact_start AS xact_start,
  	EXTRACT (
  	epoch 
  FROM
  	( now() - pgsa.xact_start )) AS xact_stay,
  	pgsa.query_start AS query_start,
  	EXTRACT (
  	epoch 
  FROM
  	( now() - pgsa.query_start )) AS query_stay,
  	pgsa.query AS query 
  FROM
  	pg_stat_activity AS pgsa 
  WHERE
  	pgsa.STATE != 'idle' 
  	AND pgsa.STATE != 'idle in transaction' 
  	AND pgsa.STATE != 'idle in transaction (aborted)' 
  	) idleconnections 
  ORDER BY
  	query_stay DESC 
  	LIMIT 50;