CODEWITHSUNDEEP
orientdb
Ryan
Ryan

Reputation: 2460

Different results for select and traverse?

I'm experimenting with OrientDb with the sample vehicle history database and have executed these two SQL queries, which I (would have thought) would be identical. I am trying to find all of the females who sold a vehicle to a male.

SELECT expand(out('Bought').in('Sold')[gender="Female"]) FROM Person 
  WHERE gender = "Male" LIMIT = -1

This one returns 124 records.

While

SELECT FROM ( TRAVERSE in('Sold') FROM (   
  SELECT FROM ( TRAVERSE out('Bought') FROM ( 
    SELECT FROM Person WHERE gender = "Male")
  ) WHERE @class = "Transaction" )) 
WHERE @class = "Person" and gender = "Female" LIMIT = -1

Returns 117 records.

I was hoping someone could explain to me what the difference is?

Upvotes: 1

Views: 406

Answers (2)

Lvca
Lvca

Reputation: 9060

@codemix is right, to have the same result use set() that excludes duplicated:

SELECT FROM (
  TRAVERSE in('Sold') FROM (   
    SELECT FROM (
      TRAVERSE set( out('Bought') ) FROM ( 
        SELECT FROM Person WHERE gender = "Male"
      )
    ) WHERE @class = "Transaction"
  )
) 
WHERE @class = "Person" and gender = "Female" LIMIT = -1

Upvotes: 1

codemix
codemix

Reputation: 672

We resolved this on gitter, but for anyone else wondering - this happens because the second query will remove duplicates (because of the traverse) but the first one won't.

Upvotes: 2

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