將兩個單獨的SQL查詢的結果與“ OR”組合

Question

框架：Rails 2.3.8數據庫； PostgreSQL的

我目前有以下SQL語句（由Rails生成）

SELECT "outbreaks".* FROM "outbreaks" INNER JOIN "bacterial_agents" ON bacterial_agents.outbreak_id = outbreaks.id INNER JOIN "bacteria" ON "bacteria".id = "bacterial_agents".bacterium_id WHERE (bacteria.name ILIKE E'%VTEC O157%')

SELECT "outbreaks".* FROM "outbreaks" INNER JOIN "viral_agents" ON viral_agents.outbreak_id = outbreaks.id INNER JOIN "virus" ON "virus".id = "viral_agents".virus_id WHERE (virus.name ILIKE E'%NOROVIRUS%')

使用下表（我已經跳過了未使用的屬性，並且布局/鍵的命名取決於Rails約定）

outbreaks
  id

bacterial_agents
  id
  outbreak_id
  bacterium_id

bacteria
  id
  name

viral_agents
  id
  outbreak_id
  virus_id

viruses
  id
  name

任何想法，我如何將上面兩個帶有“ OR”條件的SQL語句結合起來，以選擇與細菌表相關的爆發記錄，其中細菌.name如“ VTEC O157”，或與病毒表相關的病毒。名稱像“ NOROVIRUS”？

*編輯

關於Rails生成SQL的一些說明-當前輸出以下SQL

SELECT "outbreaks".* FROM "outbreaks" INNER JOIN "bacterial_agents" ON bacterial_agents.outbreak_id = outbreaks.id INNER JOIN "bacteria" ON "bacteria".id = "bacterial_agents".bacterium_id INNER JOIN "viral_agents" ON outbreaks.id = viral_agents.outbreak_id INNER JOIN "viruses" ON "viral_agents".virus_id = "viruses".id WHERE ((bacteria.name ILIKE E'%VTEC O157%') AND (viruses.name ILIKE E'%NOROVIRUS%')) LIMIT 1

本質上，我想將前兩個語句的組合結果輸出為與上述語句類似的格式（用“ OR”條件代替“ AND”）。 但是，如果這不可能，我只需要編寫一個作用域來處理SQL聯合。

想想從下面的答復來看，我將結合兩個單獨的聲明，加油：)

Answer 1

我認為您將SQL聯合運算符與OR混淆，無法將兩個查詢的返回值結合在一起。

OR用於管理語句的WHERE部分中的條件，而union用於將一個查詢附加到另一個查詢。

您應該注意，僅當兩個查詢具有相同的域時，聯合才有效。 通過快速查看您的查詢，它應該完全符合您的想法。

嘗試這個：

SELECT "outbreaks".* FROM "outbreaks" INNER JOIN "bacterial_agents" ON bacterial_agents.outbreak_id = outbreaks.id INNER JOIN "bacteria" ON "bacteria".id = "bacterial_agents".bacterium_id WHERE (bacteria.name ILIKE E'%VTEC O157%')
UNION
SELECT "outbreaks".* FROM "outbreaks" INNER JOIN "viral_agents" ON viral_agents.outbreak_id = outbreaks.id INNER JOIN "virus" ON "virus".id = "viral_agents".virus_id WHERE (virus.name ILIKE E'%NOROVIRUS%')

Answer 2

只需在查詢之間放置一個UNION ALL

SELECT "outbreaks".* 
  FROM "outbreaks"
  INNER JOIN "bacterial_agents"     ON bacterial_agents.outbreak_id = outbreaks.id 
  INNER JOIN "bacteria"         ON "bacteria".id = "bacterial_agents".bacterium_id
WHERE (bacteria.name ILIKE E'%VTEC O157%')

UNION ALL

SELECT "outbreaks".*
   FROM "outbreaks"
   INNER JOIN "viral_agents"    ON viral_agents.outbreak_id = outbreaks.id 
   INNER JOIN "virus"       ON "virus".id = "viral_agents".virus_id
 WHERE (virus.name ILIKE E'%NOROVIRUS%')