To query multiple tables

Rails
1

Hi every body,

I have a database containing around 15 tables. There are lots of
relationships. Now if I need to add a query involving say 8
tables(a,b,c,d,e,f,g,h) can I do it using find_by_sql. If so where do I
implement the method, inside the class of which table.

Thanks

2

On 17 Jan 2008, at 12:00, Pankaj jyoti Barua wrote:

Hi every body,

I have a database containing around 15 tables. There are lots of
relationships. Now if I need to add a query involving say 8
tables(a,b,c,d,e,f,g,h) can I do it using find_by_sql.
You can do anything you want pretty much using find_by_sql
If so where do I
implement the method, inside the class of which table.

If you call Foo.find_by_sql will return an array of objects of class
Foo. With that in mind it’s completely up to you

Fred

3

Frederick C. wrote:

On 17 Jan 2008, at 12:00, Pankaj jyoti Barua wrote:

Hi every body,

I have a database containing around 15 tables. There are lots of
relationships. Now if I need to add a query involving say 8
tables(a,b,c,d,e,f,g,h) can I do it using find_by_sql.
You can do anything you want pretty much using find_by_sql
If so where do I
implement the method, inside the class of which table.

If you call Foo.find_by_sql will return an array of objects of class
Foo. With that in mind it’s completely up to you

Fred

Thanks.

So I will have to create a class called foo. From where should I call
foo. Actually I have created the database using migration and I have
implemented a cgi script that gives a front end to query the database.
I am finding problem with some queries now which are preety complex.

4

It would be better to use Model.connection.execute, this will take an
sql command, and the name that goes into the log file.

WW

On Jan 17, 7:49 am, Pankaj jyoti Barua <rails-mailing-l…@andreas-

5

On Jan 17, 4:00 am, Pankaj jyoti Barua <rails-mailing-l…@andreas-
s.net> wrote:

I have a database containing around 15 tables. There are lots of
relationships. Now if I need to add a query involving say 8
tables(a,b,c,d,e,f,g,h) can I do it using find_by_sql. If so where do I
implement the method, inside the class of which table.

Just pick one. :slight_smile: It doesn’t much matter to you what kind of object is
returned by find_by_sql (or connection.execute). It’ll have attributes
for every column in the SELECT. So pick one as a “controller” (our
term, not Rails’) and go through it. It’s really just a matter of self-
documentation. In what model would you look for this method?

///ark