Thing DB - Web DevelopmentYouTube↗  IA↗(long shot)
Education  6.8K views 34 likes 1 dislikes   27 May 2012
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次にThing DBに変えました[br]Redditコードでは今でもTDBとなっていると思います
so we switched to a thing called thing DB and it's still called I think it's still called T DB in the reddit code so
TDBかTDB2というコードです　TDB2は
if you find any code that's called T DB
私が書いたThing DBのバージョン2です
or t DB - I think this was the second version of the thing DB that I wrote at
TDB2は次のようなリンクテーブルを持っています
some point this is what it's referring to instead of having a table that look
このように各thingに別々の列を作るのではなく
like this a link table with a bunch of different columns on it for different things we would instead do something
2つのプロパティを持つテーブルを作成したのです
like this we'd have a table that just had a couple properties on it and a
1つのthingに2つのプロパティです
couple properties that everything had
すべてのthingには[br]スコアと作成者と日付が含まれています
let me see if I can remember these things everything has a score an author and a
またスコアにカプセル化された[br]他のフィールドもあるでしょう
date there might be a few other fields like ups and downs kind of encapsulated
そのthingがリンクでもコメントでもsubredditでも
in score but basically everything whether it's a link whether it's a
すべてのthingにはこの固定の列があります
comment whether it's a sub reddits anything has these fixed columns it's
これは特に役に立つわけではありません
not useful for all of them it was pretty
これはthingテーブルといって
common enough this was called the thing table and then we had a separate table
この他に3つの列を持つデータテーブルがあります
that every data type had called the data table and the data table basically had
このテーブルにはthing IDとキーと値が含まれています
three columns it had the thing ID which thing are we referring to and it had a key and a value so for a particular data
例えばデータ型がある特定のリンクだとすると[br]次のように表されます
type for a link for example link might be represented like this we'd have an
thingテーブルにエントリがあると[br]スコアが5でIDが1
entry in the thing table it might have a score of five and of course it has an ID
作成者は0　これは私のIDです[br]それから日付が入ります
one an author of zero that was my user ID a date when it was submitted and then
データテーブルには多数の行が入ります
it may have a data table and may have a bunch of rows in the data table so would
1行目はthing IDが1でここにURL[br]次の行はthing IDが1でここにタイトルです
have one row that would be like thing ID one equal to R and then another row being ID one title and so for every
すべてのthingに共通しないthingのプロパティには
property of a thing that wasn't common
データテーブルに行を作成します[br]これがもう1つのデータテーブルです
across all of the things we would have a row in the data table and these are actually different database tables and
この方法により項目追加の作業が速くなりました
they could be on different machines this allowed us to add features much quicker
リンクにデータ型を足す時は
because if we wanted to add a new data
新しい行を足すだけでよく
type to links it was just the new link
古いリンクの行を足さずに[br]コードをキープするだけでいいのです
so start getting that new row we wouldn't have to go fiddle around with adding it for all the old links you
デフォルト値を持つと見せかけるリンクは
could just keep in our code the difference if a link doesn't have this
このプロパティがありません　それはすごいことです
property pretend it has a default value
データ型をあらかじめ得ることなく[br]あらゆる項目を足すことができるからです
and this was really cool it allows us to add all sorts of features without having to get the data types right way in
また新しいデータ型を足すこともできます
advance and it also allowed us to add
例えば行の下にsubredditを足すと
all these new data types for example
ユーザは自分のカテゴリを作ることができます[br]これがthingです
down the road we'd add subreddits so users can make their own kind of categories their own reddit's and that's
これで開発のプロセスがシンプルになり[br]私はこのデータテーブルに
just a thing and so it made our development process a lot simpler and then I wrote this whole layer that would
Pythonオブジェクトを関連づけるレイヤを書いたのです
kind of map our Python objects to these data tables
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