我想在postgresql中創建數據透視表類型視圖,並且差不多在那裏!這是基本的查詢:使用CASE在postgresql中創建數據透視表的正確方法WHERE
select
acc2tax_node.acc, tax_node.name, tax_node.rank
from
tax_node, acc2tax_node
where
tax_node.taxid=acc2tax_node.taxid and acc2tax_node.acc='AJ012531';
而且數據:
acc | name | rank
----------+-------------------------+--------------
AJ012531 | Paromalostomum fusculum | species
AJ012531 | Paromalostomum | genus
AJ012531 | Macrostomidae | family
AJ012531 | Macrostomida | order
AJ012531 | Macrostomorpha | no rank
AJ012531 | Turbellaria | class
AJ012531 | Platyhelminthes | phylum
AJ012531 | Acoelomata | no rank
AJ012531 | Bilateria | no rank
AJ012531 | Eumetazoa | no rank
AJ012531 | Metazoa | kingdom
AJ012531 | Fungi/Metazoa group | no rank
AJ012531 | Eukaryota | superkingdom
AJ012531 | cellular organisms | no rank
我想獲得如下:
acc | species | phylum
AJ012531 | Paromalostomum fusculum | Platyhelminthes
我試圖用CASE WHEN做到這一點,所以我有儘可能多的:
select
acc2tax_node.acc,
CASE tax_node.rank WHEN 'species' THEN tax_node.name ELSE NULL END as species,
CASE tax_node.rank WHEN 'phylum' THEN tax_node.name ELSE NULL END as phylum
from
tax_node, acc2tax_node
where
tax_node.taxid=acc2tax_node.taxid and acc2tax_node.acc='AJ012531';
這使我的輸出:
acc | species | phylum
----------+-------------------------+-----------------
AJ012531 | Paromalostomum fusculum |
AJ012531 | |
AJ012531 | |
AJ012531 | |
AJ012531 | |
AJ012531 | |
AJ012531 | | Platyhelminthes
AJ012531 | |
AJ012531 | |
AJ012531 | |
AJ012531 | |
AJ012531 | |
AJ012531 | |
AJ012531 | |
現在我知道,我必須按在某些時候ACC,所以我儘量
select
acc2tax_node.acc,
CASE tax_node.rank WHEN 'species' THEN tax_node.name ELSE NULL END as sp,
CASE tax_node.rank WHEN 'phylum' THEN tax_node.name ELSE NULL END as ph
from
tax_node, acc2tax_node
where
tax_node.taxid=acc2tax_node.taxid and acc2tax_node.acc='AJ012531'
group by acc2tax_node.acc;
,但我得到了可怕的
ERROR: column "tax_node.rank" must appear in the GROUP BY clause or be used in an aggregate function
我之前找到的所有示例都使用了CASE語句中的SUM(),所以我猜這就是聚合函數。我一直在使用FIRST()嘗試:
select
acc2tax_node.acc,
FIRST(CASE tax_node.rank WHEN 'species' THEN tax_node.name ELSE NULL END) as sp,
FIRST(CASE tax_node.rank WHEN 'phylum' THEN tax_node.name ELSE NULL END) as ph
from tax_node, acc2tax_node where tax_node.taxid=acc2tax_node.taxid and acc2tax_node.acc='AJ012531' group by acc2tax_node.acc;
,但得到的錯誤:
ERROR: function first(character varying) does not exist
誰能提供任何提示?
能否請您發佈此查詢的結果:' SELECT * FROM acc2tax_node WHERE acc ='AJ012531''? – Quassnoi 2010-03-19 13:04:53