I'm using Mysql and I'm having a difficult time trying to get the results from a SELECT query. I am having 3 tables. First table sections, second table section members and third table section member status(data in this table is static).
select * from Sections;
| section_id | title | description | section_ownerid |
-------------------------------------------------------
| 1 | title1 | desc1 | 100 |
| 2 | title2 | desc2 | 100 |
| 3 | title3 | desc3 | 100 |
| 4 | title4 | desc4 | 100 |
| 5 | title5 | desc5 | 100 |
| 6 | title6 | desc6 | 100 |
select * from SectionMembers;
| SectionMembers_id | section_id | status_code | memberid |
------------------------------------------------------------
| 1 | 1 | 10 | 200 |
| 2 | 1 | 20 | 300 |
| 3 | 2 | 30 | 200 |
| 4 | 2 | 10 | 300 |
| 5 | 3 | 30 | 200 |
| 6 | 4 | 20 | 200 |
select * from MemberStatus;
| MemberStatus_id | status_code | status |
---------------------------------------------------
| 1 | 10 | PENDINGMEMBER |
| 2 | 20 | ACTIVEMEMBER |
| 3 | 30 | MEMBERREJECTED |
I used joins to get results as
select distinct(a.section_id) as id,
a.title,
a.description,
c.status
from Sections a
left join SectionMembers b on a.section_id = b.section_id
inner join MemberStatus c on b.status_code = c.status_code
where (a.section_ownerid = 100 and b.memberid = 200)
or (a.section_ownerid = 100);
But I am not getting correct result. I want results as shown below:
| section_id | title | description | status |
------------------------------------------------------
| 1 | title1 | desc1 | PENDINGMEMBER |
| 2 | title2 | desc2 | ACTIVEMEMBER |
| 3 | title3 | desc3 | MEMBERREJECTED |
| 4 | title4 | desc4 | ACTIVEMEMBER |
| 5 | title5 | desc5 | NULL |
| 6 | title6 | desc6 | NULL |
It seems like the following query is what you need. Notice that the filter for memberid = 200
has been moved to the join condition:
select s.section_id,
s.title,
s.description,
m.status
from Sections s
left join SectionMembers sm
on s.section_id = sm.section_id
and sm.memberid = 200
left join MemberStatus m
on sm.status_code = m.status_code
where s.section_ownerid = 100;
Note: while your desired result shows that section_id=2
has a status of ActiveMember
there is no way in your sample data to make this value link to section 2.
This query gives the result:
| SECTION_ID | TITLE | DESCRIPTION | STATUS |
------------------------------------------------------
| 1 | title1 | desc1 | PendingMember |
| 2 | title2 | desc2 | MemberRejected |
| 3 | title3 | desc3 | MemberRejected |
| 4 | title4 | desc4 | ActiveMember |
| 5 | title5 | desc5 | (null) |
| 6 | title6 | desc6 | (null) |