Slow SQL queries - sql

Question

I'm having some issues with my webpage.
It was running really slow, so I read on the Internet that it might be a bad usage of SQL. So I commented the SQL lines that were more 'complex' and it started running smoothly again.
My question is: 'Is there a way to make this SQL request "lighter"?
#companies = Company.where('tbl_companys.state = "enabled"')
#companies = #companies.includes(:benefit).where("tbl_benefits.end_date >= {Date.today}" )
#companies = #companies.includes(:benefit).where(tbl_benefits: { state: 'enabled' })
has_benef_gastro = false
has_benef_hote = false
has_benef_ent = false
until has_benef_gastro == true
#esta_gastro = (#companies.where('id_category = "2-gastronomia"').shuffle)[0]
#benefit_gastro = Benefit.where('id_company = ? AND end_date >= ? AND state = "enabled"', #esta_gastro.id_company, Date.today).first
if #benefit_gastro.nil? == false
has_benef_gastro = true
end
end
until has_benef_hote == true
#esta_hotelero = (#companies.where('id_category = "1-hoteleria"').shuffle)[0]
#benefit_hote = Benefit.where('id_company = ? AND end_date >= ? AND state = "enabled"', #esta_hotelero.id_company, Date.today).first
if #benefit_hote.nil? == false
has_benef_gastro = true
end
end
until has_benef_ent == true
#esta_ent = (#companies.where('id_category = "3-entretenimiento"').shuffle)[0]
#benefit_ent = Benefit.where('id_company = ? AND end_date >= ? AND state = "enabled"', #esta_ent.id_company, Date.today).first
if #benefit_ent.nil? == false
has_benef_gastro = true
end
end
Thanks for your help !

Answer 1

You're shuffling the #esta_gastro, #esta_hotelero, #esta_ent, and the #benefit_ variables every time, which doesn't really make sense. It requires multiple new DB queries every single time you do a loop.
If you want to find a random selection, just create your sets outside of the loop, shuffle once (outside of the loop), and then iterate over those sets until you meet your criteria.
For example:
#esta_gastro = #companies.where('id_category = "2-gastronomia"').shuffle
#benefits = Benefit.where('end_date >= ? AND state = "enabled"', Date.today)
#benefit_gastro = nil
i = 0
until !#benefit_gastro.blank?
#benefit_gastro = #benefits.where('id_company = ?', #esta_gastro[i].id_company).first
i += 1
end
EDIT
If the whole goal is to get the #benefit_gastro defined, then I don't even think you need a loop. You could just define the #esta_gastro set and then use it find all the Benefits that correspond. Because #esta_gastro is shuffled, your #benefit_gastro will be random:
#esta_gastro = #companies.where('id_category = "2-gastronomia"').shuffle
#benefit_gastro = Benefit.where('end_date >= ? AND state = "enabled"', Date.today).where('id_company = ?', #esta_gastro.map(&:id)).limit(1)

Answer 2

I ended up doing a plain SQL request so I didn't had to struggle with some rails issues.
Thanks anyway !