我的方法或逻辑存在问题。
我试图将两个表中的所有数据相加。如果两者相符，则将它们相加，如果其中任何一个不对应，仍然显示单个查询总数，最后按顺序每年估算。 我尝试过LEFT JOINS，FULL JOINS，（UNIONS）。没有什么能够尽可能地总结并提供数据。 这里的关键点是pb和th_year信息是需要结果的年份。
错误必须在我的代码中明显。
单独的聚合查询会产生正确的结果。
它是我错误的两个查询的组合。
对此表示赞赏。
我认为这很简单。
我认为这可能很简单。只是愚蠢在我身边。
CREATE VIEW public.cf_th_data_totals_by_year_by_wc_2
AS SELECT
a.owner,
a.region,
a.district,
a.plantation,
b.th_year,
a.pb,
a.wc,
sum(a.tcf_calcarea + b.tth_calcarea) AS area,
sum(a.tcf_total + b.tth_total) AS total,
sum(a.tcf_ws + b.tth_ws) AS ws,
sum(a.tcf_util + b.tth_util) AS util,
sum(a.tcf_s + b.tth_s) AS s,
sum(a.tcf_a + b.tth_a) AS a,
sum(a.tcf_b + b.tth_b) AS b,
sum(a.tcf_c + b.tth_c) AS c,
sum(a.tcf_d + b.tth_d) AS d
FROM
(SELECT
cfdata.owner,
cfdata.region,
cfdata.district,
cfdata.plantation,
cfdata.pb,
cfdata.wc,
sum(cfdata.calcarea)AS tcf_calcarea,
sum(cfdata._ba) AS tcf_ba,
sum(cfdata._total) AS tcf_total,
sum( cfdata._ws) AS tcf_ws,
sum( cfdata._util) AS tcf_util,
sum( cfdata._s) AS tcf_s,
sum( cfdata._a) AS tcf_a,
sum( cfdata._b) AS tcf_b,
sum( cfdata._c) AS tcf_c,
sum( cfdata._d) AS tcf_d
FROM cfdata
GROUP BY cfdata.owner, cfdata.region, cfdata.district, cfdata.plantation, cfdata.pb, cfdata.wc
ORDER BY cfdata.owner, cfdata.region, cfdata.district, cfdata.plantation, cfdata.pb, cfdata.wc) a
JOIN
(SELECT
thdata.owner,
thdata.region,
thdata.district,
thdata.plantation,
thdata.th_year,
thdata.wc,
sum(thdata.calcarea)AS tth_calcarea,
sum(thdata.th_ba) AS tth_ba,
sum(thdata.th_total) AS tth_total,
sum(thdata.th_ws) AS tth_ws,
sum(thdata.th_util) AS tth_util,
sum(thdata.th_s) AS tth_s,
sum(thdata.th_a) AS tth_a,
sum(thdata.th_b) AS tth_b,
sum(thdata.th_c) AS tth_c,
sum(thdata.th_d) AS tth_d
FROM thdata
GROUP BY thdata.owner, thdata.region, thdata.district, thdata.plantation, thdata.th_year, thdata.wc
ORDER BY thdata.owner, thdata.region, thdata.district, thdata.plantation, thdata.th_year, thdata.wc) b
ON a.owner = b.owner AND a.region = b.region AND a.district = b.district and a.plantation = b.plantation AND a.pb = b.th_year AND a.wc = b.wc
GROUP BY a.owner, a.region, a.district, a.plantation, a.pb, b.th_year, a.wc
ORDER BY a.owner, a.region, a.district, a.plantation, a.pb, b.th_year, a.wc
thdata样本：
owner region district plantation compartment calcarea wc plantdate th_year th_age th_dbh th_ht th_vtree th_sph th_ba th_total th_ws th_util th_s th_a th_b th_c th_d thdata_id
KeyProjects Northern Marshlands River Glen A27 14.02 PFN 01/08/2009 2017 8 12.3 7.3 0.0289 179 28 70 14 56 42 14 0 0 0 1
KeyProjects Northern Marshlands River Glen A28 2.1 ESN 01/12/2010 2012 2 4.5 4.2 0 479 2 0 0 0 0 0 0 0 0 2
KeyProjects Northern Marshlands River Glen A28 2.1 ESN 01/12/2010 2014 4 10.2 9.6 0.0188 250 4 11 0 8 4 6 0 0 0 3
KeyProjects Northern Marshlands River Glen A29 2.71 ESN 01/08/2009 2011 2 4.5 4.2 0 479 3 0 0 0 0 0 0 0 0 4
KeyProjects Northern Marshlands River Glen A29 2.71 ESN 01/08/2009 2013 4 10.2 9.6 0.0188 250 5 14 0 11 5 8 0 0 0 5
thdata样本：
owner region district plantation compartment wc pb calcarea cfage dbh ht vtree sph _ba _total _ws _util _s _a _b _c _d tmai umai smai cfdata_id
KeyProjects Northern Marshlands River Glen A01 EF1 2021 5.27 10 14.5 20.4 0.1109 1004 90 585 21 564 84 401 79 0 0 11.1 10.7 1.5 1
KeyProjects Northern Marshlands River Glen A02 EF1 2021 36.1 10 14.5 20.4 0.1109 1004 614 4007 144 3863 578 2744 542 0 0 11.1 10.7 1.5 2
KeyProjects Northern Marshlands River Glen A03 EF1 2021 5.5 10 14.5 20.4 0.1109 1004 94 611 22 589 88 418 83 0 0 11.1 10.7 1.5 3
KeyProjects Northern Marshlands River Glen A04 EF1 2021 11.91 10 14.5 20.4 0.1109 1004 202 1322 48 1274 191 905 179 0 0 11.1 10.7 1.5 4
KeyProjects Northern Marshlands River Glen A05 EF1 2022 39.17 11 14.9 21.8 0.1286 1000 705 5053 157 4857 666 3486 744 0 0 11.7 11.3 1.7 5
预期结果：
owner region district plantation th_year pb wc area total ws util s a b c d
KeyProjects Northern Marshlands River Glen 2008 2008 EF1 620.49 44176 1788 42389 7562 31953 2852 0 0
KeyProjects Northern Marshlands River Glen 2009 2009 EF1 635.65 44319 1778 42476 7634 31993 2852 0 0
KeyProjects Northern Marshlands River Glen 2010 2010 EF1 1202.31 87980 3453 84487 14906 63883 5704 0 0
KeyProjects Northern Marshlands River Glen 2011 2011 EF1 1948.37 132378 5275 127104 22662 95895 8556 0 0
KeyProjects Northern Marshlands River Glen 2012 2012 EF1 1378.61 87928 3429 84477 14878 63922 5704 0 0
答案 0 :(得分：0)
好的，您的查询存在一些问题：
sum(a.tcf_calcarea + b.tth_calcarea) AS area。您可以简单地添加，但是您应该确保先使用NULL替换任何0值：代替所有coalesce(a.tcf_calcarea, 0) + coalesce(b.tth_calcarea, 0) AS area来代替sum()。这也意味着您不再在此级别进行聚合，因此您应该删除最终的GROUP BY子句。FULL OUTER JOIN。这意味着您可以从连接的两个子查询中获取所有行，并且任何一方都不存在相应的行，列值为NULL。ORDER BY毫无意义，规划器将以最佳方式处理行集。您应该只在外层订购。b.th_year = a.pb，您可以删除两列中的一列。一些语法指针：
GROUP BY子句中使用位置参数，这样您就可以编写GROUP BY 1, 2, 3, 4, 5, 6。与ORDER BY相同。JOIN子句中，您可以撰写USING (owner, region, district, plantation, wc)，然后添加WHERE a.pb = b.th_year。除此之外，对于任何USING列，您不再需要主查询中的子查询别名。但是，一个连接条件没有相应的列名这一事实确实会使事情稍微混乱;由你决定。总而言之，这就是你得到的：
CREATE VIEW public.cf_th_data_totals_by_year_by_wc_2 AS
SELECT owner, region, district, plantation, b.th_year, wc,
coalesce(a.tcf_calcarea, 0) + coalesce(b.tth_calcarea, 0) AS area,
...
FROM (
SELECT owner, region, district, plantation, pb, wc,
sum(calcarea) AS tcf_calcarea,
...
FROM cfdata
GROUP BY 1, 2, 3, 4, 5, 6) a
FULL JOIN (
SELECT owner, region, district, plantation, th_year, wc,
sum(calcarea) AS tth_calcarea,
...
FROM thdata
GROUP BY 1, 2, 3, 4, 5, 6) b
USING (owner, region, district, plantation, wc)
WHERE a.pb = b.th_year
ORDER BY 1, 2, 3, 4, 5, 6;