Dealing with multiple SQL queries within single find_by_sql

Question

Please note that I understand I could do the following in a single SQL query that's not the point of the question however... I'm more curious about how rails deals with multiple queries.

Let's say I have a Movies model with attributes such as title, director, id, star, release date, etc.

Now I have @Movies = find_by_sql("select * from movies where genre='Action';select * from movies where genre='Comedy';")

And I iterate through it on the view. However only the first query results seem to be contained in the answer. Just curious about how this works.

Thanks

i am not able to run multiple queries how can i do that??

yednamus
– yednamus

2013-11-13 12:18:36 +00:00
Commented Nov 13, 2013 at 12:18 — yednamus
– yednamus, Commented Nov 13, 2013 at 12:18

David Sulc · Accepted Answer · 2010-11-29 01:09:11Z

1

This should work

@Movies = find_by_sql("select * from movies where genre='Action' or genre='Comedy';")

Edit: this is maybe what you're refering to with the single query.

Another way to do it is

find_by_genre('Action') << find_by_genre('Comedy')

answered Nov 29, 2010 at 1:09

David Sulc

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2 Comments

Msencenb Over a year ago

Yeah this was what I was referring to as a single query. Not really interested in getting the query results I want more interested in how rails deals with it.

David Sulc Over a year ago

I think "the rails way" would be the second one: fetch result for each category and return concatenated arrays. If you want only one DB trip, I think you'll have to use the single query (or a variation).

COD3BOY · Accepted Answer · 2012-01-11 16:57:21Z

0

Try the UNION SELECT... sql query...

Also, LOL cs142?

edited Jan 11, 2012 at 16:57

COD3BOY

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answered Nov 29, 2010 at 13:41

John Doe

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1 Comment

Msencenb Over a year ago

Yes CS142 and yes union select is the correct way to do it. Since the multiple query was my first attempt though I am still curious about how Rails handles multiple queries with the find_by_sql command. Looks like it just stops after the first query?

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