SQL比较两个具有公共ID的表，但表2中的ID可能位于两个不同的列中

Question

Given the following SQL tables:

Administrators:

id  Name   rating
 1  Jeff      48
 2  Albert    55
 3  Ken       35
 4  France    56
 5  Samantha  52
 6  Jeff      50

Meetings:

id   originatorid    Assitantid
1              3             5
2              6             3
3              1             2
4              6             4

I would like to generate a table from Ken's point of view (id=3) therefore his id could be possibly present in two different columns in the meetings' table. (The statement IN does not work since I introduce two different field columns).

Thus the ouput would be:

id   originatorid    Assitantid
1              3             5
2              6             3

Answer 1

If you really just need to see which column Ken's id is in, you only need an OR . The following will produce your example output exactly.

SELECT * FROM Meetings WHERE originatorid = 3 OR Assistantid = 3;

If you need to take the complex route and list names along with meetings, an OR in your join's ON clause should work here:

SELECT 
  Administrators.name,
  Administrators.id,
  Meetings.originatorid,
  Meetings.Assistantid
FROM Administrators
   JOIN Meetings 
     ON Administrators.id = Meetings.originatorid 
     OR Administrators.id = Meetings.Assistantid
Where Administrators.name = 'Ken'