SQLite3: select columns from multiple tables by many IDs

Question

Suppose there are three tables: A , B and C . Each has id column ( INTEGER NOT NULL PRIMARY KEY ) and data column ( TEXT ). There is also another table - records - with fields:

record_id  INTEGER NOT NULL PRIMARY KEY,
a_id       INTEGER,
b_id       INTEGER,
c_id       INTEGER,
...

How to select A . data , B . data and C . data for a certain record ( record_id = <some value> ) by a_id , b_id and c_id accordingly when the latter can be either valid IDs or zeros (so each column in the result can be a TEXT value or NULL )?

Answer 1

Assuming the Sample data, following is my query using left joins-

select r.record_id,
       a.text as a_txt,
       b.text as b_txt,
       c.text as c_txt
  from records r
left join tablea a
        on r.a_id=a.id
left join tableb b
        on r.b_id=b.id
left join tablec c
        on r.c_id=c.id
where r.record_id=<Some Value>;