Rails + Postgres Array + ANY LIKE - Adam Niedzielski
Ruby on Rails has a good support for Postgres Array type. I really like using this feature when creating a separate database table sounds like over-engineering. In this short post I want to share my solution for the following problem: “find a record for which any of its tags contains a given stringâ€. Let’s use Book model with categories array field as an example. We start by generating a migration
PostgreSQLã®é…列を使ã£ã¦æ–‡å—列を集約をã™ã‚‹æ–¹æ³• | dTblog | デザインã¨ãƒ—ãƒã‚°ãƒ©ãƒ ã®å¢ƒç•Œã‚’ã•ã¾ã‚ˆã†ãƒ–ãƒã‚°
1対N（OneToMany）ã®é–¢ä¿‚ã«ã‚ã‚‹2ã¤ã®ã‚¨ãƒ³ãƒ†ã‚£ãƒ†ã‚£ã«ã¤ã„ã¦ã€N個ã®æ–‡å—列を集約ã™ã‚‹å¿…è¦ãŒã‚ã£ã¦ã€æ–¹æ³•ã‚’考ãˆã¦ã¿ãŸã€‚ 次ã®ã‚ˆã†ãªéƒ¨ç½²ãƒžã‚¹ã‚¿ã¨ç¤¾å“¡ãƒžã‚¹ã‚¿ã‚’例ã«ã¨ã£ã¦ã€èª¬æ˜Žã—ã¾ã™ã€‚ ã“ã‚Œã«å¯¾ã—ã¦ã€æ¬¡ã®ã‚ˆã†ãªè¡¨ã‚’出ã™ã¨ã„ã†è¦ä»¶ã€‚ 部署 所属社員 å–¶æ¥1課 「2ã¤ã®ã‚¨ãƒ³ãƒ†ã‚£ãƒ†ã‚£ã‚’ JOIN ã™ã‚Œã°è‰¯ã„ã˜ã‚ƒã‚“ã€ã¨ã„ã†å£°ã‚‚ã‚ã‚‹ã‘ã©ã€å˜ç´”ã«çµåˆã—ã¡ã‚ƒã†ã¨ã€çµæžœã‚»ãƒƒãƒˆã‹ã‚‰å–り出ã™ã¨ãã€ã‚‚ã—ãã¯è¡¨ç¤ºæ™‚点ã§ãƒ—ãƒã‚°ãƒ©ãƒ ã§ã”ã«ã‚‡ã”ã«ã‚‡ã‚„らãªã„ã¨ã€ã†ã¾ãã„ã‹ãªã„。所属社員ã®ä¸€è¦§ã‚’ã€æ”¹è¡ŒåŒºåˆ‡ã‚Šã®æ–‡å—列ã¨ã—ã¦ã€ã²ã¨ã¤ã®å¤‰æ•°ã«æ ¼ç´ã§ãã‚Œã°ã€ã‚‰ãã¡ã‚“。è¦ã™ã‚‹ã«ã€DBã‹ã‚‰å€¤ã‚’å–å¾—ã™ã‚‹æ™‚点ã§ã€è¡¨ç¤ºã™ã‚‹ã¨ãã®å½¢ã¾ã§æŒã£ã¦ã„ããŸã„ã¨ã„ã†è©±ã€‚ ã“ã“ã®æ–¹æ³•ã«ã¤ã„ã¦ã¯è³›å¦ä¸¡è«–ã‚ã‚‹ã‹ã‚‚ã—ã‚Œãªã„ã‘ã©ã€SQLã¯ãƒ—ãƒã‚°ãƒ©ãƒ ãŒæœ€ã‚‚シンプルã§æ¸ˆã‚€ã‚ˆã†ãªçµæžœãŒå¾—られるよã†ã«æ›¸ãã¹ãã ã¨æ€ã£ã¦ã¾ã™ã€‚ 話ãŒé€¸ã‚ŒãŸã‘ã©ã€ã˜ã‚ƒã‚ã€ãれをã©ã†ã‚„ã£ã¦ã‚„ã‚‹ã‹
Rubyã§ã®é †åˆ—ã€çµ„ã¿åˆã‚ã›ã€‚ - simanã®ãƒ–ãƒã‚°
Rubyã§ã¯ã€Œé †åˆ—ã€ã¨ã€Œçµ„ã¿åˆã‚ã›ã€ã‚’Arrayクラスã®combinationメソッドã¨permutationメソッドを用ã„ã‚‹ã“ã¨ã§ã€ç°¡å˜ã«æ±‚ã‚ã‚‹ã“ã¨ãŒã§ãã¾ã™ã€‚ array = [1,2,3,4] p array.combination(3).to_a [[1, 2, 3], [1, 2, 4], [1, 3, 4], [2, 3, 4]]combinationã®å¼•æ•°ã¯é¸ã³å‡ºã™è¦ç´ ã®å€‹æ•°ã‚’指定ã™ã‚‹ã€‚ array = [1,2,3] p array.permutation(3).to_a [[1, 2, 3], [1, 3, 2], [2, 1, 3], [2, 3, 1], [3, 1, 2], [3, 2, 1]]両方ã¨ã‚‚便利ãªãƒ¡ã‚½ãƒƒãƒ‰ã§ã™ã€‚ ã¾ãŸã€è¦ç´ ã®é‡è¤‡ã‚’許å¯ã™ã‚‹å ´åˆã¯ repeated_combination ã‚„ repeated_permutation ãŒåˆ©ç”¨ã§ãã¾ã™ã€‚ ãªãœ
Rails 4.0 Sneak Peek: PostgreSQL array support - DockYard
I’m happy to announce that Rails 4.0 now has support for PostgreSQL arrays. You can create an array column easily at the time of migration by adding :array => true. Creating an array column will respect the other options you add to the column (length, default, etc). create_table :table_with_arrays do |t| t.integer :int_array, :array => true # integer[] t.integer :int_array, :array => true, :length
tappã«ã¤ã„ã¦ãã‚ãã‚一言言ã£ã¦ãŠãã‹ - ã‘ã‚“ã¡ã‚ƒã‚“ãã‚“ã•ã‚“ã®Web日記
弊社ã§(ç·åŠ›ã‚’上ã’ã¦)メンテナンスã—ã¦ã„ã‚‹tappã¨ã„ã†ãƒ©ã‚¤ãƒ–ラリãŒã‚ã‚‹ã®ã§ã™ãŒã€æ€ã£ãŸã‚ˆã‚ŠèªçŸ¥åº¦ãŒä½Žã„よã†ãªã®ã§ã“ã“ã§ç´¹ä»‹ã•ã›ã¦ã„ãŸã ãã¾ã™ã€‚ ã¾ã¨ã‚ tappã¯ã€å¾“æ¥ã®Print Debugã®å•é¡Œç‚¹ã‚’解決ã™ã‚‹ç”»æœŸçš„ãªãƒ©ã‚¤ãƒ–ラリã§ã™ã€‚ 次ã®ã‚ˆã†ãªçµŒé¨“ãŒã‚ã‚‹æ–¹ã¯ã€ã„ã¾ã™ãGemfileã«tappã‚’è¿½åŠ ã™ã‚‹ã“ã¨ã‚’ãŠå‹§ã‚ã—ã¾ã™ã€‚ メソッドãƒã‚§ãƒ¼ãƒ³ã®é–“ã®ã‚ªãƒ–ジェクトã®çŠ¶æ…‹ã‚’見るãŸã‚ã ã‘ã«ä¸€æ™‚変数を使ã£ãŸã“ã¨ãŒã‚ã‚‹ ppã‚„pã€putsを消ã—忘れã¦ãƒªãƒã‚¸ãƒˆãƒªã«ã‚³ãƒŸãƒƒãƒˆã—ã¦ã—ã¾ã£ãŸ tappã¨ã¯ tappã¯ã€Print Debugã‚’ç°¡å˜ã«è¡Œã†ãŸã‚ã®Rubyライブラリã§ã™ã€‚ リãƒã‚¸ãƒˆãƒªã¯https://github.com/esminc/tappã«ãªã‚Šã¾ã™ã€‚ tappã®æ´å² tappã®ä½œè€…ã§ã‚ã‚‹@ursmã¯ã€2008〜2009å¹´é ƒã«ç¤¾å†…å‘ã‘ã®ãƒ¢ãƒ³ã‚ーパッãƒã¨ã—ã¦tappを生ã¿ã ã—ã€Rails勉強会41.
PostgreSQLã§é…列型ã®ã‚«ãƒ©ãƒ を使ã£ã¦ã¿ã‚‹ - ã±ã›ã‚‰ã‚“メモ
PostgreSQLã§ã¯ã‚«ãƒ©ãƒ ã®ãƒ‡ãƒ¼ã‚¿åž‹ã«é…列を使ã†ã“ã¨ãŒå‡ºæ¥ã‚‹ã€‚ã„ã¡ãŠã†SQL99æº–æ‹ ãªã®ã‹ãªã€‚ 何ã¯ã¨ã‚‚ã‚れテーブルを作æˆã™ã‚‹ SQLã¯ã“ã‚“ãªæ„Ÿã˜ã€‚ CREATE TABLE favorites ( username varchar(20), -- ユーザå category varchar(20), -- カテゴリå items varchar(100)[], -- アイテムå（複数） PRIMARY KEY(username, category) ); itemsã®éƒ¨åˆ†ãŒé…列。プãƒã‚°ãƒ©ãƒŸãƒ³ã‚°è¨€èªžã®ã‚ˆã†ã«åž‹åã«æ‹¬å¼§ã‚’付ã‘ãŸå½¢ã§æŒ‡å®šã™ã‚‹ã€‚ 括弧内ã«è¦ç´ 数を指定ã™ã‚‹ã“ã¨ã‚‚ã§ãã‚‹ãŒã€ç¾åœ¨ã®å®Ÿè£…ã§ã¯è¦ç´ æ•°ã®æŒ‡å®šã¯ç„¡è¦–ã•ã‚Œã€ç„¡åˆ¶é™ã¨ã—ã¦æ‰±ã‚れるã¨ã®ã“ã¨ï¼ˆä½†ã—SQL99ã®ä»•æ§˜ã§ã¯è¦ç´ æ•°ã¯å›ºå®šã«ã—ã‹ã§ããªã„）。 ã¾ãŸã€é…列ã®å®£è¨€æ–¹æ³•ã¯SQL99ã«æº–æ‹ ã—ãŸitems varchar(100) ARR
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GitHub - tlconnor/activerecord-postgres-array: Postgres array support for Active Record
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