COUNT个同一列的多种类型 [英] COUNT multiple types of same column

问题描述

在我当前的查询中:

SELECT COUNT(WC.ID) AS "Regions" 
FROM WHOLE_FEATURES_PDB_CHAINS AS WC 
;

我COUNT(WC.ID) AS "Regions". 但是，我们有多个具有WC.Type的区域，可以为1,2,3,4.我需要根据WC.Type将每种类型出现的次数计入COUNT(WC.ID) AS "Region_1"，COUNT(WC.ID) AS "Region_2".... 有什么办法可以在一个查询中解决这个问题?我正在查看MySQL IF，但不知道如何将其集成到count函数中.

I COUNT(WC.ID) AS "Regions" . However, we have multiple regions with WC.Type can be 1,2,3,4. I need to count each type occurrence into COUNT(WC.ID) AS "Region_1", COUNT(WC.ID) AS "Region_2" ... depending on WC.Type. Is there any way to solve this in one query? I am looking at MySQL IF, yet do not know how to integrate it into the count function.

我需要将其放在一行中(此处显示的查询已减少，这是一个较大的查询)

I need it to be in one row (the shown query here is reduced, it's a larger query)

SELECT COUNT(WC.ID) AS "Region_1" , COUNT(WC.ID) AS "Region_2" ...

如果有人感兴趣，这里是完整的查询:

Here is the complete query if anyone is interested:

SELECT PCS.PDB_id, PCS.Chain, PPA.ENSEMBL_start, PPA.ENSEMBL_end, PPA.eValue, PIN.TITLE AS "pdbTitle", COUNT(WC.ID) AS "Regions" 
FROM PDB_Chains AS PCS 
LEFT JOIN WHOLE_FEATURES_PDB_CHAINS AS WC ON WC.PDB_CHAIN_ID = PCS.idPDB_chains, PDB_protein_alignment PPA, PDB_INFOS PIN 
WHERE PCS.idPDB_chains = PPA.idPDB_Chains 
AND PCS.PDB_id = PIN.PDB_ID 
AND PPA.idProteins = (SELECT idProteins from Proteins WHERE ENSEMBL_protein_id = "'+submittedID+'") 
GROUP BY PCS.PDB_id, PCS.Chain ORDER BY PCS.PDB_id;

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这是根据您的回答得出的有效的解决方案

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Here's the working solutin based on your kind answers

SELECT PIN.TITLE AS "pdbTitle", COUNT(CASE WHEN WC.STRUCTURAL_FEATURES_ID = 1 then 1 end) AS "PPInterface" , COUNT(CASE WHEN WC.STRUCTURAL_FEATURES_ID = 4 then 1 end) AS "flexibleRegions" 
FROM PDB_Chains AS PCS LEFT JOIN WHOLE_FEATURES_PDB_CHAINS AS WC ON WC.PDB_CHAIN_ID = PCS.idPDB_chains, PDB_protein_alignment PPA, PDB_INFOS PIN 
WHERE PCS.idPDB_chains = PPA.idPDB_Chains 
AND PCS.PDB_id = PIN.PDB_ID 
AND PPA.idProteins = (SELECT idProteins from Proteins WHERE ENSEMBL_protein_id = "ENSP00000256078.4") 
GROUP BY PCS.PDB_id, PCS.Chain ORDER BY PCS.PDB_id;

推荐答案

您可以在聚合函数中使用when语句时使用大小写.

You can use case when statement inside your aggregate function.

尝试一下.

count(WC.type = 1然后1结束的情况)作为region_1，类似地对另一列重复.

count(case when WC.type = 1 then 1 end) as region_1, similarly repeat for another column.

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