Select 来自具有联接的多个表

Question

我有这个问题。我想 select

surgery Type
surgery Details
Modality ID

我至少走在正确的道路上吗？

LINKtable是一切的中间

Addmission 1toM on LINK
Surgery Mto1 on LINK
Modality Mto1 on LINK

我的问题是将 Modality.ID 添加到结果中。
跳过模态，查询有效 100%

已更新（删除多别名）

SELECT surg.srg_Details, surg.Type, modd.ID
FROM Surgery surg
JOIN LINK lnk on lnk.lnk_ID = surg.srg_lnkID
JOIN Modality modd ON modd.mod_lnkID = lnk.lnk_ID
JOIN Admission adm ON adm.adm_ID = lnk.lnk_admID
WHERE  adm.adm_ID = 192100042

Answer 1

本例尝试使用：

SELECT surg.srg_Details, surg.Type, mod.ID
FROM Surgery surg, Modality mod
JOIN LINK lnk on lnk.lnk_ID = surg.srg_lnkID
JOIN Admission adm ON adm.adm_ID = lnk.lnk_admID
WHERE  adm.adm_ID = 192100042 AND surg.srg_lnkID = mod.mod_lnkID

Answer 2

Try to use left Join though no match null value will be present

SELECT surg.srg_Details, surg.Type, mod.ID
FROM Surgery surg, Modality mod
left JOIN LINK lnk on lnk.lnk_ID = surg.srg_lnkID
left JOIN Modality mod ON mod.mod_lnkID = lnk.lnk_ID
left JOIN Admission adm ON adm.adm_ID = lnk.lnk_admID
WHERE  adm.adm_ID = 192100042

Select 来自具有联接的多个表

Select result from multi tables with joins

sql

4d-database