我的查询如下所示:
SELECT mthreport.*
FROM crosstab
('SELECT
to_char(ipstimestamp, ''mon DD HH24h'') As row_name,
varid::text || log.varid || ''_'' || ips.objectname::text As bucket,
COUNT(*)::integer As bucketvalue
FROM loggingdb_ips_boolean As log
INNER JOIN IpsObjects As ips
ON log.Varid=ips.ObjectId
WHERE ((log.varid = 37551)
OR (log.varid = 27087)
OR (log.varid = 50876)
OR (log.varid = 45096)
OR (log.varid = 54708)
OR (log.varid = 47475)
OR (log.varid = 54606)
OR (log.varid = 25528)
OR (log.varid = 54729))
GROUP BY to_char(ipstimestamp, ''yyyy MM DD HH24h''), row_name, objectid, bucket
ORDER BY to_char(ipstimestamp, ''yyyy MM DD HH24h''), row_name, objectid, bucket' )
As mthreport(item_name text, varid_37551 integer,
varid_27087 integer ,
varid_50876 integer ,
varid_45096 integer ,
varid_54708 integer ,
varid_47475 integer ,
varid_54606 integer ,
varid_25528 integer ,
varid_54729 integer ,
varid_29469 integer)
可以使用此连接字符串对测试表进行测试:“host = bellariastrasse.com port = 5432 dbname = IpsLogging user = guest password = guest”
查询在语法上是正确的并且运行正常 . 我的问题是它的COUNT(*)值总是填充最左边的列 . 但是,在许多情况下,左列应该为零或NULL,并且只应填充第2(或第n)列 . 我的大脑正在融化,我无法弄清楚出了什么问题!
1 回答
您的问题的解决方案是使用带有 two parameters 的
crosstab()
变体 .第二个参数(另一个查询字符串)生成输出列的列表,以便正确分配数据查询中的NULL值(第一个参数) .
检查manual for the tablefunc extension,特别是crosstab(text, text):
强调我的 . 我最近发布了几个相关答案here或here或here .