title: self join with inner join on other tables together
body: <p>I have a database with 3 tables records, categories, relational. </p>
  
  <pre><code>records (id, lat, lng)
  categories (c_id, c_value)
  relational (r_id, c_id)
  
  records
  id  | lat      | lng
  ----------------------
  1    23.57258   -35.28412
  2    23.54855   -35.18881
  3    23.74128   -35.17469
  
  categories
  c_id | c_value
  ---------------
  100    groceries
  101    bags
  102    drinks
  
  relational
  id  |  c_id
  ------------
  1     100
  1     102
  2     101
  3     100
  </code></pre>
  
  <p>The relational.r_id = records.id and the relational.c_id = categories.c_id
  I want to take pairs from records with different c_value, so I want to make a self join in records and inner join in categories and relational.
  I've made this without the self join in records</p>
  
  <pre><code>SELECT id, lat, lng, c_value 
  FROM records 
  JOIN relational 
    ON records.id = relational.id 
  JOIN categories 
    ON relational.c_id = categories.c_id 
  WHERE c_value = "V1"  
  </code></pre>
  
  <p>I tried something like this but it didn't work. I have problem with the R1.c_value.</p>
  
  <pre><code>SELECT R1._id, R1.lat, R1.lng, R1.c_value, R2._id, R2.lat, R2.lng, 
         R2.c_value 
  FROM records R1, records R2 
  JOIN relational 
    ON records.id = relational.id 
  JOIN categories 
    ON relational.c_id = categories.c_id 
  WHERE R1.c_value = "groceries" AND R2.c_value = "bags"
  </code></pre>
  
  <p>Do you know how can I combine those 3 joins in order to take 2 rows from records with the criteria of the other tables?
  I want to have an output like this:
  For "groceries" and "bags" as c.value</p>
  
  <pre><code>1 | 23.57258  |  -35.28412  |  groceries | 2  | 23.54855  |  -35.18881  |  bags    
  </code></pre>