SQL Advanced Features: Left Join
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Inner join -> join

select *
from a,b
where a.id1 = b.id2;

select *
from
   a join b on a.id1=b.id2;

Outer join ->

Left outer join -> inner join tuples union tuples from A that did not
participate in the join

select *
from
   a left join b on a.id1=b.id2;

Right outer join -> inner join tuples union tuples from B that did not
participate in the join


select *
from
   a right join b on a.id1=b.id2;

Full outer join -> inner join tuples union tuples from B that did not
participate in the join union tuples from A that did not
participate in the join

Full outer join:

select *
from
   a full join b on a.id1=b.id2;

------------------------


select
  b.baker
  , count(f.episodeid) as numfavorites
from
   bakers b
   left join favorites f
    on b.baker = f.baker
group by
   b.baker;


List of bakers who were never a favorite

select
  b.baker
from
   bakers b
   left join favorites f
    on b.baker = f.baker
where
   f.baker is null;

equal to:

select
  b.baker
from
   bakers b
except
select
   baker
from
   favorites ;

---------

Return for all bakers how many times they were rank 1 in technicals.

select
   b.baker
from
   bakers b
   left join technicals t
     on b.baker = t.baker
        and t.rank=1
where
   t.baker is null;