From: khaines@...
Date: 2006-12-06T09:45:57+09:00
Subject: Re: Lisp comprehensions => SQL

On Wed, 6 Dec 2006, Victor "Zverok" Shepelev wrote:

A lot of these things are either supported in Kansas, or are in the 
drawing board for when I can get back to Kansas development.

> employees = Table.new(:id, :name, :sec_name, :salary, :age)
>
> employees.select{|e| e.name == 'John' && e.salary > 50}.sort_by{|e|
> e.age}[2,10]

Current Kansas:

dbh.select(:Employees) do |e|
   sort_by(e.age)
   limit(2,10)
   (e.name == 'John') & (e.salary > 50)
end

Future Kansas:

employees = Kansas::DBNAME::Employees
employees.select do |e|
   sort_by(e.age)
   limit(2,10)
   (e.name == 'John') & (e.salary > 50)
end

> employees.select{|e| e.salary < 150}.count

Current:

dbh.count(:Employees) {|e| e.salary < 150}

Future:

employees.count {|e| e.salary < 150}

> employees = Table.new(:id, :name, :sec_name, :salary, :age)
> positions = Table.new(:id, :employee_id, :position_name)
>
> (employees + positions).select{|e, p| e.id == p.employee_id}

Current:

dbh.select(:Employees, :Positions) {|e,p| e.id == p.employee_id}


I have not worked on Kansas much in the last year because it is stable for 
me, but there are a number of things that I have planned when I can set 
aside some time to get back around to it.


Kirk Haines