Connecting 5 tables but excluding values from the 5th

Question

Data tables

I got 5 tables with certain values:

1. Table: tbl_1

+-------+-------+
| nm_id | name  |
+-------+-------+
|     1 | name1 |
|     2 | name2 |
|     3 | name3 |
+-------+-------+

2. Table: tbl_2

+-------+-------+-------+
|post_id| nm_id | post  |
+-------+-------+-------+
|     1 |     1 | text1 |
|     2 |     1 | text2 |
|     3 |     2 | text3 |
+-------+-------+-------+

3. Table: tbl_3

+-------+-------+-------+-------+
|com_id |post_id| nm_id | com   |
+-------+-------+-------+-------+
|     1 |     1 |     1 | text1 |
|     2 |     2 |     1 | text2 |
|     3 |     2 |     2 | text3 |
+-------+-------+-------+-------+

4. Table: tbl_4

+-------+-------+-------+-------+-------+
|com2_id|com_id||post_id| nm_id | com2  |
+-------+-------+-------+-------+-------+
|     1 |     1 |     1 |     1 | text1 |
|     2 |     2 |     2 |     1 | text2 |
|     3 |     1 |     2 |     2 | text3 |
+-------+-------+-------+-------+-------+

5. Table: tbl_5

+-------+-------+-------+-------+-------+-------+
|rep_id |com2_id|com_id||post_id| nm_id | text  |
+-------+-------+-------+-------+-------+-------+
|     1 |  null |     1 |     1 |     1 | text1 |
|     2 |  null |  null |     1 |     1 | text2 |
+-------+-------+-------+-------+-------+-------+

What I tried

I need to get all the values, but the idea is to exclude values from tbl_5 from result. So far what I do is:

1. select tbl_2 then join tbl_1 on nm_id then exclude tbl_5 on post_id -> 1stVariable

SELECT tbl_2.*, name.tbl_1
FROM tbl_2
INNER JOIN tbl_2 ON tbl_1.nm_id = tbl_2.nm_id
LEFT JOIN tbl_5 ON tbl_2.post_id = tbl_5.post_id
WHERE tbl_2.post_id = *variable* AND tbl_5.rep_id IS NULL

2. select tbl_3 then join tbl_2 on com_id then join tbl_1 on nm_id exclude tbl_5 on com_id -> 2ndVariable

SELECT tbl_3.*, name.tbl_1
FROM tbl_3
INNER JOIN tbl_3 ON tbl_1.nm_id = tbl_3.nm_id
LEFT JOIN tbl_5 ON tbl_3.com_id = tbl_5.com_id
WHERE tbl_3.com_id = *variable* AND tbl_5.rep_id IS NULL

3. select tbl_4 then join tbl_1 on nm_id exclude tbl_5 on com2_id -> 3rdVariable

SELECT tbl_4.*, name.tbl_1
FROM tbl_4
INNER JOIN tbl_4 ON tbl_1.nm_id = tbl_4.nm_id
LEFT JOIN tbl_5 ON tbl_4.com2_id = tbl_5.com2_id
WHERE tbl_4.com2_id = *variable* AND tbl_5.rep_id IS NULL

My current output is JSON

{
  post:{...},
  com:{...},
  com2:{...}
}

Needed JSON output

What happens is that my .js gets so long and complicated with 3 separated arrays. I was trying to get everything within 1st variable, what i can't understand is how to get array within array:

{
   post: {
     post_id: "post_id",
     name: "name",
     com: {
       com_id:"com_id",
       com:"com",
       name:"name",
       com2:{
         com2_id:"com2_id",
         com2:"com2",
         name:"name",
         }
      },
   }
}

I really hope this is understandable. Thanks in advance.

Answer 1

I would expect a query like this:

select . . .    -- columns you want
from . . .      -- joins among the first four tables
where not exists (select 1
                  from table_5 t5
                  where . . .    -- conditions that match table 5 to the other tables
                 );

I can speculate that your conditions are something like:

where not exists (select 1
                  from table_5 t5
                  where t5.com_id = t4.com_id and
                        t5.post_id = t2.post_id and
                        t5.nm_id = t1.nm_id
                 )

but your question is not clear on how the tables are matched.