COUNT個同一列的多種類型

Question

在我當前的查詢中：

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

我將COUNT(WC.ID) AS "Regions" 。 但是，我們有多個具有WC.Type的區域，可以是1,2,3,4 。 我需要將每種類型出現的次數都計入COUNT(WC.ID) AS "Region_1" ， COUNT(WC.ID) AS "Region_2" ...，具體取決於WC.Type 。 有什么辦法可以在一個查詢中解決這個問題？ 我正在查看MySQL IF ，但不知道如何將其集成到count函數中。

我需要將其放在一行中（此處顯示的查詢已減少，這是一個較大的查詢）

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

如果有人感興趣，這是完整的查詢：

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;

---

這是根據您的喜好而定的解決方案

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;

Answer 1

Select
...
...
sum(if WC.ID = 1 then 1 else 0) as Region1,
sum(if WC.ID = 2 then 1 else 0) as Region2,
sum(if WC.ID = 3 then 1 else 0) as Region3,
sum(if WC.ID = 4 then 1 else 0) as Region4

可能會做您想要的。

Answer 2

您可以在聚合函數中使用case when語句。

嘗試這個 。

count（WC.type = 1然后1結束的情況）作為region_1，類似地對另一列重復。

Answer 3

您可以將GROUP BY與COUNT以獲取所需的結果，例如：

SELECT WC.Type, COUNT(WC.ID) AS "Regions" 
FROM WHOLE_FEATURES_PDB_CHAINS AS WC 
GROUP BY WC.Type;

更新資料

如果要將計數作為每個區域的樞軸列，則可以編寫內部SELECT查詢，例如：

SELECT
 (SELECT COUNT(ID) FROM WHOLE_FEATURES_PDB_CHAINS WHERE type = 1) AS "Region_1",
 (SELECT COUNT(ID) FROM WHOLE_FEATURES_PDB_CHAINS WHERE type = 2) AS "Region_2",
other_column
FROM WHOLE_FEATURES_PDB_CHAINS AS WC
WHERE <some condition>;