良いアプリケーションは良いデータベースに宿る

2019/11/27 Classi Rails Night

Transcript

1. ྑ͍ΞϓϦέʔγϣϯ͸ ྑ͍σʔλϕʔεʹ॓Δ 2019.11.27 Classi Rails Night ླ໦߁म(@y_s____731)
2. • ླ໦߁म • AGBIOTECHגࣜձࣾ • Ruby/Rails/ΤϯδχΞྺ 3೥໨ • લ৬͸T̋Y̋TAͰઃඋͷमཧͯ͠·ͨ͠ɻ • twitter @y_s_____731
3. લஔ͖
4. σʔλϕʔεɾɾɾ • ೔ʑ͞ΘͬͯΔ͸ͣ • ҙࣝͤͣͱ΋͞ΘΕͯ͠·͏ • RailsʢActiveRecordʣͷੌ͞
5. ͳ͔ͳ͔ݴٴ͞Εͳ͍
6. ͍͟ຊ൪؀ڥˠແࣄࢮ๢
7. σʔλϕʔεΛ஌Βͣʹ ྑ͍ΞϓϦέʔγϣϯ͸࡞Εͳ͍
9. Classi͞ΜͷΠϕϯτ͕ ݸਓతʹλʔχϯάϙΠϯτ
10. 1.໊લॏཁ
11. ͦΜͳ͜ͱ΋͋ͬͯɺࢲͷઃܭ্ͷ࠲ӈͷ໏͸ʮ໊લॏཁʯ Ͱ͢ɻ ͋ΒΏΔػೳΛσβΠϯ͢Δ࣌ʹɺࢲ͸ͦͷ໊લʹ΋ͬͱ΋ ͩ͜ΘΓ·͢ɻ ϓϩάϥϚͱͯ͠ͷΩϟϦΞͷதͰɺద੾ͳ໊લΛ͚ͭΔ͜ ͱ͕Ͱ͖ͨػೳ͸੒ޭ͠ɺͦ͏Ͱͳ͍ػೳʹ͍ͭͯ͸ޙͰޙ չ͢Δ͜ͱ͕ଟ͔ͬͨΑ͏ʹࢥ͏͔ΒͰ͢ɻ by Matz
12. σʔλϕʔε΋ಉ͡
13. σʔλϕʔεʹ͓͚Δ໊લɾɾɾ • ςʔϒϧ໊ • ΧϥϜ໊
14. ୭͕Ͳ͏Έͯ΋ɺԿΛදͯ͠Δ͔෼͔Δ
15. ந৅× ۩ମత̋ ʢUser → Teature, Studentͱ͔ʣ ந৅తͳ໊લ͸੹຿͕ᐆດʹͳΓ͕ͪ ↪︎FatModelʹͳΓ΍͍͢
16. ུ͞ͳ͍ ʢྫ.༵೔ dow× day_of_week̋ʣ ಛʹαʔϏεݻ༗ͷݴ༿ͳͲུ͞ΕΔͱ ޙ͔Βೖͬͨਓ͸͖ͬͱਏ͍
17. 2.੍໿Λ׆༻͢Δ
18. ੍໿ RDBMS͕ඪ४Ͱ͍࣋ͬͯΔ ೖྗ஋Λ੍ݶ͢Δػೳ
19. ੍໿ͷछྨɾɾɾ • NOT NULL੍໿ • ForeignKey(֎෦Ωʔ)੍໿ • UNIQUE੍໿ • CHECK੍໿…etc
20. NOT NULL ੍໿ NULLΛېࢭ͢Δ
21. class CreateArticles < ActiveRecord::Migration[5.2] def change create_table :articles do |t| t.string :title, null: false t.text :content, null: false t.timestamps end end end
22. ࠷ॳʹ͚ͭΔͷ͸؆୯ɻ Ͱ΋ɺޙ͔Β௥Ճ͠ਏ͍͜ͱ΋ɻ
23. جຊతʹNOT NULL͚ͭΔ ↓ Կ͕NULLABLEͳͷ͔Λߟ͑Δ
24. ֎෦Ωʔ ੍໿ ผͷςʔϒϧͷಛఆͷΧϥϜʹ͋Δ஋͔͠ ೖྗͰ͖ͳ͍Α͏ʹ͢Δػೳ
25. Α͘࢖͏ͷ͸தؒςʔϒϧ ϑΥϩʔɾϑΥϩϫʔΈ͍ͨͳؔ࿈෇͚Ͱ ଘࡏ͠ͳ͍ϢʔβʔΛϑΥϩʔͰ͖ͳ͍Α͏ʹ͢Δ
27. class CreateRelationships < ActiveRecord::Migration[5.2] def change create_table :relationships do |t| t.references :user, foreign_key: true, null: false t.references :followed, foreign_key: { to_table: :users }, null: false t.timestamps end end end
28. ΧϥϜ໊ͱࢀরઌͷ໊લ͕ಉ͡ foreign_key: true ҧ͏৔߹ foreign_key: { to_table: :ςʔϒϧ໊ }
29. DBͷ੔߹ੑΛอͭ࠷ޙͷࡆ = ੍໿
30. ੍໿͸ͪΌΜͱ࢖͍·͠ΐ͏
31. 3.ΞϓϦέʔγϣϯ͋Γ͖ͰDBΛߟ͑ͳ͍
32. Railsͷಛ௃ ςʔϒϧ = Ϋϥε
33. ςʔϒϧઃܭͱ࣮૷Λಉ࣌ʹߟ͕͑ͪ
34. ҰͭͷΞΧ΢ϯτʹෳ਺ͷϩʔϧ͕͋Δ ྫ.ചΓखͱങ͍ख
36. class User < ApplicationRecord # ڞ௨ͷ৘ใ end class Seller < ApplicationRecord has_many :selling_items, dependent: :destroy ɹ# ചΓखʹؔ͢ΔϦϨʔγϣϯ # ചΓखʹؔ͢ΔϏδωεϩδοΫ end class Buyer < ApplicationRecord # ങ͍खʹؔ͢ΔϦϨʔγϣϯ # ങ͍खʹؔ͢ΔϏδωεϩδοΫ end
37. ໨త ϦϨʔγϣϯͱϏδωεϩδοΫͷ෼ׂ ↓ ςʔϒϧ࡞Δͷ͸৑௕
39. class User < ApplicationRecord # ڞ௨ͷ৘ใ end class Seller < User has_many :selling_items, dependent: :destroy ɹ# ചΓखʹؔ͢ΔϦϨʔγϣϯ # ചΓखʹؔ͢ΔϏδωεϩδοΫ end class Buyer < User # ങ͍खʹؔ͢ΔϦϨʔγϣϯ # ങ͍खʹؔ͢ΔϏδωεϩδοΫ end
40. Ϋϥεͱͯ͠ඞཁ ≠ ςʔϒϧ࡞Δ
41. ݴΘΕΔͱ౰વͳΜ͚ͩͲ ҰਓͰ΍ͬͯΔͱҊ֎ϛε͍ͬͯΔ
42. ·ͱΊ
43. ·ͱΊ • ΞϓϦέʔγϣϯͷϑϨʔϜϫʔΫ͕มΘΔ͜ͱ͸͋ͬͯ΋ σʔλϕʔε͕·ΔͬͱมΘΔ͜ͱ͸ͳ͔ͳ͔ͳ͍ɻ • ͔ͩΒͦ͜ɺσʔλϕʔε͸ઃܭͳͲΛ͓Ζ͔ͦʹͤͣɺͪΌ Μͱ஌Δඞཁ͕͋Δɻ • ͨͩɺઃܭ͸ҰਓͰ΍ͬͯΔͱ͍ͭͷؒʹ͔ϋϚͬͯͨΓਏ͍ ͷͰɺڧ͍ਓͱҰॹʹͱ͔ɺଟਓ਺Ͱ΍ͬͨ΄͏͕Αͦ͞͏ɻ