{"id":1594,"date":"2025-06-16T13:46:54","date_gmt":"2025-06-16T04:46:54","guid":{"rendered":"https:\/\/route-zero.com\/recruit\/?post_type=route&#038;p=1594"},"modified":"2025-09-16T13:53:31","modified_gmt":"2025-09-16T04:53:31","slug":"sql%e3%82%b5%e3%83%96%e3%82%af%e3%82%a8%e3%83%aa%e3%81%af%e9%81%85%e3%81%84%ef%bc%9fjoin%e3%83%bbcte%e3%81%a8%e3%81%ae%e9%81%95%e3%81%84%e3%81%a8%e9%ab%98%e9%80%9f%e5%8c%96%e3%81%ae%e3%83%99%e3%82%b9","status":"publish","type":"route","link":"https:\/\/route-zero.com\/recruit\/route\/1594\/","title":{"rendered":"SQL\u30b5\u30d6\u30af\u30a8\u30ea\u306f\u9045\u3044\uff1fJOIN\u30fbCTE\u3068\u306e\u9055\u3044\u3068\u9ad8\u901f\u5316\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9"},"content":{"rendered":"<div>\n<h2>SQL\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u6b63\u3057\u3044\u4f7f\u3044\u65b9\uff5cJOIN\u3084CTE\u3068\u306e\u9055\u3044\u3092\u5b9f\u884c\u901f\u5ea6\u3067\u5fb9\u5e95\u6bd4\u8f03<\/h2>\n<p>SQL\u3067\u8907\u96d1\u306a\u51e6\u7406\u3092\u66f8\u3044\u3066\u3044\u308b\u3068\u3001\u300c\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u591a\u7528\u3057\u3066\u9045\u3044\u300d\u300c\u30ec\u30d3\u30e5\u30fc\u3067JOIN\u3092\u4f7f\u3048\u3068\u8a00\u308f\u308c\u305f\u300d\u3068\u3044\u3063\u305f\u7d4c\u9a13\u306f\u3042\u308a\u307e\u305b\u3093\u304b\uff1f<\/p>\n<p>\uff08SQL\u306e\u57fa\u790e\u3084\u30a8\u30e9\u30fc\u89e3\u6c7a\u306b\u3064\u3044\u3066\u306f<a href=\"https:\/\/route-zero.com\/recruit\/route\/1233\/\">\u521d\u5fc3\u8005\u5411\u3051SQL\u8b1b\u5ea7\uff5cSELECT\u6587\u306e\u66f8\u304d\u65b9\u3068\u5b9f\u884c\u9806\u3092\u5b8c\u5168\u89e3\u8aac<\/a>\u3092\u3054\u53c2\u7167\u304f\u3060\u3055\u3044\uff09<\/p>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1a\u30b5\u30d6\u30af\u30a8\u30ea<\/strong><br \/>\n    SQL\u6587\u306e\u4e2d\u306b\u5165\u308c\u5b50\u3068\u3057\u3066\u8a18\u8ff0\u3059\u308b\u5225\u306eSQL\u3002\u4e3b\u306bSELECT\u30fbFROM\u30fbWHERE\u53e5\u306a\u3069\u3067\u4f7f\u308f\u308c\u3001\u8907\u96d1\u306a\u6761\u4ef6\u3084\u96c6\u8a08\u3092\u5b9f\u73fe\u3067\u304d\u307e\u3059\u3002<\/p>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1aJOIN<\/strong><br \/>\n    \u8907\u6570\u306e\u30c6\u30fc\u30d6\u30eb\u3092\u95a2\u9023\u4ed8\u3051\u3066\u30c7\u30fc\u30bf\u3092\u53d6\u5f97\u3059\u308bSQL\u306e\u4ed5\u7d44\u307f\u3002\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\uff08\u95a2\u4fc2\u6027\uff09\u3092\u660e\u793a\u3067\u304d\u3001\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3084\u53ef\u8aad\u6027\u306b\u512a\u308c\u307e\u3059\u3002<\/p>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1aCTE\uff08\u5171\u901a\u30c6\u30fc\u30d6\u30eb\u5f0f\uff09<\/strong><br \/>\n    WITH\u53e5\u3067\u4e00\u6642\u7684\u306a\u30c6\u30fc\u30d6\u30eb\u3092\u5b9a\u7fa9\u3057\u3001\u8907\u96d1\u306a\u51e6\u7406\u3092\u5206\u5272\u30fb\u518d\u5229\u7528\u3067\u304d\u308bSQL\u306e\u8a18\u6cd5\u3002\u53ef\u8aad\u6027\u3084\u4fdd\u5b88\u6027\u304c\u5411\u4e0a\u3057\u307e\u3059\u3002<\/p>\n<\/blockquote>\n<p>\u7279\u306bSES\u5e38\u99d0\u306e\u73fe\u5834\u3067\u306f\u3001\u660e\u78ba\u306a\u8a2d\u8a08\u601d\u60f3\u3084\u30ec\u30d3\u30e5\u30fc\u57fa\u6e96\u304c\u5171\u6709\u3055\u308c\u305a\u3001\u500b\u4eba\u306e\u5b9f\u88c5\u306b\u4f9d\u5b58\u3057\u3066\u3057\u307e\u3046\u3053\u3068\u3082\u5c11\u306a\u304f\u3042\u308a\u307e\u305b\u3093\u3002\u305d\u306e\u7d50\u679c\u3001\u300c\u52d5\u304f\u3051\u3069\u3001\u3053\u306e\u66f8\u304d\u65b9\u304c\u672c\u5f53\u306b\u6b63\u3057\u3044\u306e\u3060\u308d\u3046\u304b\u300d\u300c\u3053\u306e\u66f8\u304d\u65b9\u3067\u8a55\u4fa1\u3055\u308c\u308b\u306e\u304b\u300d\u3068\u4e0d\u5b89\u3092\u611f\u3058\u308b\u5834\u9762\u3082\u5897\u3048\u3066\u3057\u307e\u3044\u307e\u3059\u3002<\/p>\n<p>\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001\u305d\u3093\u306a\u30e2\u30e4\u30e2\u30e4\u3092\u89e3\u6d88\u3059\u308b\u305f\u3081\u306b\u3001<strong>SQL\u30b5\u30d6\u30af\u30a8\u30ea<\/strong>\u306e\u57fa\u790e\u304b\u3089\u3001<strong>JOIN<\/strong>\u3084<strong>CTE<\/strong>\u3068\u306e\u6bd4\u8f03\u3001\u5b9f\u884c\u901f\u5ea6\u3084\u4fdd\u5b88\u6027\u306e\u89b3\u70b9\u3067\u306e\u4f7f\u3044\u5206\u3051\u3092\u6574\u7406\u3057\u307e\u3059\u3002<\/p>\n<p>\u307e\u305f\u3001\u306a\u305c\u3053\u3046\u3057\u305f\u5b9f\u88c5\u5224\u65ad\u304c\u30ad\u30e3\u30ea\u30a2\u8a55\u4fa1\u3084\u6848\u4ef6\u9078\u5b9a\u306b\u3064\u306a\u304c\u308b\u306e\u304b\u3082\u89e3\u8aac\u3002\u8a18\u4e8b\u3092\u8aad\u307f\u7d42\u3048\u308b\u9803\u306b\u306f\u3001\u5358\u306a\u308b\u30a8\u30e9\u30fc\u89e3\u6d88\u3060\u3051\u3067\u306a\u304f\u3001\u8a2d\u8a08\u601d\u60f3\u3092\u7406\u89e3\u3057\u3001\u81ea\u4fe1\u3092\u6301\u3063\u3066\u30ec\u30d3\u30e5\u30fc\u306b\u81e8\u3081\u308b\u77e5\u8b58\u304c\u8eab\u306b\u3064\u3044\u3066\u3044\u308b\u306f\u305a\u3067\u3059\u3002<\/p>\n<hr \/>\n<h2>1. SQL\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u57fa\u790e\u3068\u7a2e\u985e<\/h2>\n<figure>\n    <a href=\"https:\/\/route-zero.com\/recruit\/wp-content\/uploads\/2025\/09\/SQL\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u57fa\u790e\u3068\u7a2e\u985e.jpg\" target=\"_blank\" rel=\"noopener noreferrer\"><br \/>\n      <img decoding=\"async\" src=\"https:\/\/route-zero.com\/recruit\/wp-content\/uploads\/2025\/09\/SQL\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u57fa\u790e\u3068\u7a2e\u985e.jpg\" alt=\"SQL\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u57fa\u790e\u3068\u7a2e\u985e\" loading=\"lazy\" style=\"max-width:100%;height:auto;display:block;margin:0 auto;\"><br \/>\n    <\/a><figcaption>\u56f3\uff1aSQL\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u57fa\u790e\u3068\u7a2e\u985e<\/figcaption><\/figure>\n<p>SQL\u30b5\u30d6\u30af\u30a8\u30ea\u3068\u306f\u3001SQL\u6587\u306e\u4e2d\u306b\u5165\u308c\u5b50\u3068\u3057\u3066\u8a18\u8ff0\u3059\u308b\u5225\u306eSQL\u306e\u3053\u3068\u3067\u3059\u3002<\/p>\n<p>\uff08SQL\u306eCASE\u5f0f\u3084\u6761\u4ef6\u5206\u5c90\u306b\u3064\u3044\u3066\u306f<a href=\"https:\/\/route-zero.com\/recruit\/route\/1323\/\">SQL CASE\u5f0f\u306e\u4f7f\u3044\u65b9\uff5cSELECT\u30fbWHERE\u30fbUPDATE\u3067\u6761\u4ef6\u5206\u5c90\u3059\u308b\u66f8\u304d\u65b9\u3068\u3064\u307e\u305a\u304d\u89e3\u6d88\u5b9f\u4f8b<\/a>\u3092\u3054\u53c2\u7167\u304f\u3060\u3055\u3044\uff09<\/p>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1a\u30b9\u30ab\u30e9\u30fc\u30b5\u30d6\u30af\u30a8\u30ea<\/strong><br \/>\n    \u5358\u4e00\u306e\u5024\uff081\u30bb\u30eb\uff09\u3092\u8fd4\u3059\u30b5\u30d6\u30af\u30a8\u30ea\u3002SELECT\u53e5\u3067\u65b0\u3057\u3044\u5217\u3068\u3057\u3066\u4f7f\u3046\u3053\u3068\u304c\u591a\u3044\u3067\u3059\u3002<\/p>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1a\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea<\/strong><br \/>\n    \u5916\u5074\u306e\u30af\u30a8\u30ea\u306e\u5024\u3092\u53c2\u7167\u3057\u3001\u884c\u3054\u3068\u306b\u7e70\u308a\u8fd4\u3057\u5b9f\u884c\u3055\u308c\u308b\u30b5\u30d6\u30af\u30a8\u30ea\u3002\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306b\u6ce8\u610f\u304c\u5fc5\u8981\u3067\u3059\u3002<\/p>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1a\u975e\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea<\/strong><br \/>\n    \u5916\u5074\u306e\u30af\u30a8\u30ea\u3068\u306f\u72ec\u7acb\u3057\u3066\u4e00\u5ea6\u3060\u3051\u5b9f\u884c\u3055\u308c\u308b\u30b5\u30d6\u30af\u30a8\u30ea\u3002IN\u3084EXISTS\u3067\u3088\u304f\u4f7f\u308f\u308c\u307e\u3059\u3002<\/p>\n<\/blockquote>\n<p>\u5927\u304d\u304f\u5206\u3051\u3066\u3001\u4ee5\u4e0b\u306e3\u7a2e\u985e\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<ul>\n<li>\n<p><strong>\u30b9\u30ab\u30e9\u30fc\u30b5\u30d6\u30af\u30a8\u30ea<\/strong>\uff1a\u5358\u4e00\u306e\u5024\u3092\u8fd4\u3059\u30b5\u30d6\u30af\u30a8\u30ea\u3067\u3059\u3002<code>SELECT (SELECT COUNT(*) FROM users)<\/code> \u306e\u3088\u3046\u306b\u3001\u5217\u306e\u4e00\u90e8\u3068\u3057\u3066\u5229\u7528\u3057\u307e\u3059\u3002<\/p>\n<pre><code>-- \u4f8b\uff1a\u5404\u30e6\u30fc\u30b6\u30fc\u306e\u6ce8\u6587\u6570\u3092\u5217\u3068\u3057\u3066\u8fd4\u3059\uff08\u30b9\u30ab\u30e9\u30fc\u30b5\u30d6\u30af\u30a8\u30ea\uff09\r\nSELECT\r\n  u.id,\r\n  u.name,\r\n  (SELECT COUNT(*) FROM orders o WHERE o.user_id = u.id) AS order_count\r\nFROM users u;\r\n<\/code><\/pre>\n<\/li>\n<li>\n<p><strong>\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea<\/strong>\uff1a\u5916\u5074\u306e\u30af\u30a8\u30ea\u306e\u5217\u3092\u53c2\u7167\u3057\u306a\u304c\u3089\u3001\u884c\u3054\u3068\u306b\u7e70\u308a\u8fd4\u3057\u5b9f\u884c\u3055\u308c\u308b\u30b5\u30d6\u30af\u30a8\u30ea\u3067\u3059\u3002\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306b\u5f71\u97ff\u3057\u3084\u3059\u3044\u50be\u5411\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<pre><code>-- \u4f8b\uff1a\u6ce8\u6587\u304c\u5b58\u5728\u3059\u308b\u30e6\u30fc\u30b6\u30fc\u306e\u307f\u62bd\u51fa\u3059\u308b\uff08\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\uff09\r\nSELECT\r\n  u.name\r\nFROM users u\r\nWHERE EXISTS (\r\n  SELECT 1\r\n  FROM orders o\r\n  WHERE o.user_id = u.id\r\n    AND o.created_at > '2025-01-01'\r\n);\r\n<\/code><\/pre>\n<\/li>\n<li>\n<p><strong>\u975e\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea<\/strong>\uff1a\u5916\u5074\u306e\u30af\u30a8\u30ea\u3068\u306f\u72ec\u7acb\u3057\u3066\u304a\u308a\u3001\u4e00\u5ea6\u3060\u3051\u5b9f\u884c\u3055\u308c\u308b\u30b5\u30d6\u30af\u30a8\u30ea\u3067\u3059\u3002<\/p>\n<pre><code>-- \u4f8b\uff1a\u6709\u52b9\u306a\u30ab\u30c6\u30b4\u30ea\u3092\u6301\u3064\u5546\u54c1\u306e\u307f\u53d6\u5f97\u3059\u308b\uff08\u975e\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\uff09\r\nSELECT\r\n  p.*\r\nFROM products p\r\nWHERE p.category_id IN (\r\n  SELECT id FROM categories WHERE active = TRUE\r\n);\r\n<\/code><\/pre>\n<\/li>\n<\/ul>\n<h3>\u3069\u306e\u53e5\u3067\u4f7f\u3048\u308b\u304b\uff1f<\/h3>\n<ul>\n<li>\n<p><strong>SELECT\u53e5<\/strong>\uff1a\u5024\u3092\u8a08\u7b97\u3057\u3001\u65b0\u3057\u3044\u5217\u3068\u3057\u3066\u8fd4\u3057\u307e\u3059\u3002<\/p>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1aSELECT\u53e5<\/strong><br \/>\n        \u53d6\u5f97\u3057\u305f\u3044\u5217\u3084\u8a08\u7b97\u5f0f\u3092\u6307\u5b9a\u3059\u308bSQL\u306e\u57fa\u672c\u69cb\u6587\u3002\u30b5\u30d6\u30af\u30a8\u30ea\u3084\u95a2\u6570\u3082\u5229\u7528\u53ef\u80fd\u3067\u3059\u3002<\/p>\n<\/blockquote>\n<\/li>\n<li>\n<p><strong>FROM\u53e5<\/strong>\uff1a\u6d3e\u751f\u30c6\u30fc\u30d6\u30eb\uff08\u4e00\u6642\u7684\u306a\u30c6\u30fc\u30d6\u30eb\uff09\u3068\u3057\u3066\u6271\u3044\u307e\u3059\u3002<\/p>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1aFROM\u53e5<\/strong><br \/>\n        \u30c7\u30fc\u30bf\u306e\u53d6\u5f97\u5143\u3068\u306a\u308b\u30c6\u30fc\u30d6\u30eb\u3084\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u6307\u5b9a\u3059\u308b\u90e8\u5206\u3002JOIN\u3084CTE\u3068\u3082\u7d44\u307f\u5408\u308f\u305b\u307e\u3059\u3002<\/p>\n<\/blockquote>\n<\/li>\n<li>\n<p><strong>WHERE\u53e5<\/strong>\uff1a<code>IN<\/code> \u3084 <code>EXISTS<\/code> \u3068\u7d44\u307f\u5408\u308f\u305b\u3066\u3001\u6761\u4ef6\u5224\u5b9a\u306b\u4f7f\u3044\u307e\u3059\u3002<\/p>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1aWHERE\u53e5<\/strong><br \/>\n        \u30c7\u30fc\u30bf\u306e\u7d5e\u308a\u8fbc\u307f\u6761\u4ef6\u3092\u6307\u5b9a\u3059\u308bSQL\u306e\u69cb\u6587\u3002\u30b5\u30d6\u30af\u30a8\u30ea\u3084\u6bd4\u8f03\u6f14\u7b97\u5b50\u3068\u4f75\u7528\u3057\u307e\u3059\u3002<\/p>\n<\/blockquote>\n<\/li>\n<\/ul>\n<hr \/>\n<h2>2. \u30b5\u30d6\u30af\u30a8\u30ea\u3092\u5de1\u308b\u201c\u3088\u304f\u3042\u308b\u5931\u6557\u201d\u3068\u305d\u306e\u80cc\u666f<\/h2>\n<p>\u79c1\u305f\u3061\u306f\u3001\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u76f4\u611f\u7684\u306b\u4f7f\u3044\u3084\u3059\u3044\u3068\u611f\u3058\u304c\u3061\u3067\u3059\u3002\u3057\u304b\u3057\u3001\u30cd\u30b9\u30c8\u304c\u6df1\u304f\u306a\u308b\u3068\u53ef\u8aad\u6027\u304c\u4f4e\u4e0b\u3057\u3001\u30c1\u30fc\u30e0\u30e1\u30f3\u30d0\u30fc\u306e\u30ec\u30d3\u30e5\u30fc\u5de5\u6570\u3092\u5897\u3084\u3057\u3066\u3057\u307e\u3046\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<p>\uff08SQL\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u6539\u5584\u3084JOIN\u306e\u4f7f\u3044\u65b9\u306b\u3064\u3044\u3066\u306f<a href=\"https:\/\/route-zero.com\/recruit\/route\/1119\/\">SQL JOIN\u306e\u57fa\u672c\u304b\u3089\u5b9f\u8df5\u307e\u3067\uff5cINNER\u30fbLEFT\u30fbRIGHT\u30fbOUTER JOIN\u306e\u9055\u3044\u3092\u308f\u304b\u308a\u3084\u3059\u304f\u89e3\u8aac<\/a>\u3092\u3054\u53c2\u7167\u304f\u3060\u3055\u3044\uff09<\/p>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1a\u30cd\u30b9\u30c8<\/strong><br \/>\n    \u30b5\u30d6\u30af\u30a8\u30ea\u3084\u95a2\u6570\u306a\u3069\u3092\u5165\u308c\u5b50\u69cb\u9020\u3067\u91cd\u306d\u308b\u3053\u3068\u3002\u6df1\u304f\u306a\u308b\u307b\u3069\u53ef\u8aad\u6027\u3084\u4fdd\u5b88\u6027\u304c\u4f4e\u4e0b\u3057\u307e\u3059\u3002<\/p>\n<\/blockquote>\n<h4>\u5931\u6557\u4f8b\uff08\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\u306b\u3088\u308b\u6027\u80fd\u60aa\u5316\uff09<\/h4>\n<p>\u30e6\u30fc\u30b6\u30fc\u3054\u3068\u306e\u6ce8\u6587\u6570\u3092\u53d6\u5f97\u3059\u308b\u969b\u3001\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u4f7f\u3046\u3068\u30e6\u30fc\u30b6\u30fc\u6570\u5206\u3060\u3051\u5185\u5074\u304c\u5b9f\u884c\u3055\u308c\u3001\u30c7\u30fc\u30bf\u91cf\u304c\u5897\u3048\u308b\u3068\u6975\u7aef\u306b\u9045\u304f\u306a\u308a\u307e\u3059\u3002<\/p>\n<pre><code>-- \u5931\u6557\u4f8b\uff1a\u30e6\u30fc\u30b6\u30fc\u3054\u3068\u306b\u30b5\u30d6\u30af\u30a8\u30ea\u304c\u5b9f\u884c\u3055\u308c\u308b\uff08\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\uff09\r\nSELECT\r\n  u.id,\r\n  u.name,\r\n  (SELECT COUNT(*) FROM orders o WHERE o.user_id = u.id) AS order_count\r\nFROM users u;\r\n<\/code><\/pre>\n<p>\u4e0a\u8a18\u306f\u5c0f\u898f\u6a21\u306a\u3089\u554f\u984c\u306a\u3044\u3053\u3068\u3082\u3042\u308a\u307e\u3059\u304c\u3001\u30e6\u30fc\u30b6\u30fc\u6570\u304c\u591a\u3044\u74b0\u5883\u3067\u306f\u907f\u3051\u308b\u3079\u304d\u66f8\u304d\u65b9\u3067\u3059\u3002<\/p>\n<h4>\u6539\u5584\u4f8b\uff08\u96c6\u7d04\u3057\u3066JOIN\u3059\u308b\uff09<\/h4>\n<p>\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u96c6\u7d04\u3057\u3066\u304b\u3089JOIN\u3059\u308b\u3068\u3001\u5185\u5074\u306e\u51e6\u7406\u306f\u4e00\u5ea6\u3060\u3051\u5b9f\u884c\u3055\u308c\u308b\u305f\u3081\u9ad8\u901f\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<pre><code>-- \u6539\u5584\u4f8b\uff1a\u96c6\u7d04\u3057\u3066\u304b\u3089JOIN\u3059\u308b\r\nSELECT\r\n  u.id,\r\n  u.name,\r\n  COALESCE(o.order_count, 0) AS order_count\r\nFROM users u\r\nLEFT JOIN (\r\n  SELECT user_id, COUNT(*) AS order_count\r\n  FROM orders\r\n  GROUP BY user_id\r\n) o ON o.user_id = u.id;\r\n<\/code><\/pre>\n<p>\u3053\u308c\u304c\u3001\u30ec\u30d3\u30e5\u30fc\u3067\u300c<strong>JOIN<\/strong>\u306b\u66f8\u304d\u63db\u3048\u308d\u300d\u3068\u6307\u6458\u3055\u308c\u308b\u4e3b\u306a\u7406\u7531\u3067\u3059\u3002<\/p>\n<h3>\u306a\u305c\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\u306f\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u843d\u3061\u308b\u306e\u304b\uff1f<\/h3>\n<p>\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\u306f\u3001\u5916\u5074\u306e\u30af\u30a8\u30ea\u306e\u884c\u3054\u3068\u306b\u518d\u5b9f\u884c\u3055\u308c\u308b\u305f\u3081\u3001\u30c7\u30fc\u30bf\u91cf\u304c\u591a\u3044\u3068\u6975\u7aef\u306b\u9045\u304f\u306a\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1a\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9<\/strong><br \/>\n    SQL\u3084\u30b7\u30b9\u30c6\u30e0\u306e\u51e6\u7406\u901f\u5ea6\u30fb\u52b9\u7387\u3002\u30b5\u30d6\u30af\u30a8\u30ea\u3084JOIN\u306e\u4f7f\u3044\u65b9\u3067\u5927\u304d\u304f\u5909\u308f\u308a\u307e\u3059\u3002<\/p>\n<\/blockquote>\n<p>\u4f8b\u3048\u3070\u3001\u4ee5\u4e0b\u306e\u30b3\u30fc\u30c9\u3092\u898b\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n<pre><code>SELECT name\r\nFROM users u\r\nWHERE EXISTS (\r\n    SELECT 1 FROM orders o WHERE o.user_id = u.id\r\n);<\/code><\/pre>\n<p>\u3053\u306e\u66f8\u304d\u65b9\u3067\u306f\u3001<strong>\u30e6\u30fc\u30b6\u30fc\u6570 \u00d7 \u6ce8\u6587\u6570<\/strong>\u306e\u8a55\u4fa1\u304c\u767a\u751f\u3057\u3001\u5927\u898f\u6a21\u306a\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3067\u306f\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u8457\u3057\u304f\u4f4e\u4e0b\u3059\u308b\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<h3>\u53ef\u8aad\u6027\u30fb\u4fdd\u5b88\u6027\u3092\u8efd\u8996\u3059\u308b\u30ea\u30b9\u30af<\/h3>\n<ul>\n<li>\n<p>\u30ec\u30d3\u30e5\u30fc\u5de5\u6570\u304c\u5897\u3048\u3001\u958b\u767a\u5168\u4f53\u306e\u30b9\u30d4\u30fc\u30c9\u304c\u843d\u3061\u308b<\/p>\n<\/li>\n<li>\n<p>\u5f8c\u4efb\u306e\u62c5\u5f53\u8005\u304c\u30b3\u30fc\u30c9\u306e\u610f\u56f3\u3092\u8aad\u307f\u89e3\u304d\u3065\u3089\u3044<\/p>\n<\/li>\n<li>\n<p>\u6848\u4ef6\u5168\u4f53\u306e\u4fe1\u983c\u6027\u304c\u4f4e\u4e0b\u3059\u308b<\/p>\n<\/li>\n<\/ul>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1a\u53ef\u8aad\u6027\u30fb\u4fdd\u5b88\u6027<\/strong><br \/>\n    \u53ef\u8aad\u6027\u306f\u300c\u30b3\u30fc\u30c9\u306e\u8aad\u307f\u3084\u3059\u3055\u300d\u3001\u4fdd\u5b88\u6027\u306f\u300c\u4fee\u6b63\u3084\u62e1\u5f35\u306e\u3057\u3084\u3059\u3055\u300d\u3002\u3069\u3061\u3089\u3082\u9ad8\u3044\u307b\u3069\u30c1\u30fc\u30e0\u958b\u767a\u3067\u6709\u5229\u3067\u3059\u3002<\/p>\n<\/blockquote>\n<p>SES\u306e\u73fe\u5834\u3067\u306f\u3001\u300c\u52d5\u304f\u30b3\u30fc\u30c9\u300d\u3092\u66f8\u3051\u308b\u3053\u3068\u3060\u3051\u3067\u306a\u304f\u3001\u300c\u8ab0\u304c\u898b\u3066\u3082\u7406\u89e3\u3067\u304d\u308b\u30b3\u30fc\u30c9\u300d\u3092\u66f8\u3051\u308b\u3053\u3068\u304c\u8a55\u4fa1\u306b\u3064\u306a\u304c\u308a\u307e\u3059\u3002<\/p>\n<hr \/>\n<h2>3. JOIN\u30fbCTE\u30fb\u30a6\u30a3\u30f3\u30c9\u30a6\u95a2\u6570\u3068\u306e\u6bd4\u8f03<\/h2>\n<p>\u3067\u306f\u3001<strong>\u30b5\u30d6\u30af\u30a8\u30ea<\/strong>\u306f\u3001\u4ed6\u306e\u624b\u6cd5\u3068\u6bd4\u3079\u3066\u3069\u3046\u3067\u3057\u3087\u3046\u304b\u3002<\/p>\n<h3>\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u6bd4\u8f03<\/h3>\n<p><strong>\u5c0f\u898f\u6a21\u30c7\u30fc\u30bf<\/strong>\u3067\u306f\u3001<strong>\u30b5\u30d6\u30af\u30a8\u30ea<\/strong>\u3068<strong>JOIN<\/strong>\u306b\u4f53\u611f\u3067\u304d\u308b\u307b\u3069\u306e\u5dee\u306f\u307b\u3068\u3093\u3069\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n<p>\u4e00\u65b9\u3067\u3001<strong>\u5927\u898f\u6a21\u30c7\u30fc\u30bf<\/strong>\u3067\u306f\u3001<strong>JOIN<\/strong>\u3084<strong>CTE<\/strong>\u306e\u65b9\u304c\u4e00\u822c\u7684\u306b\u9ad8\u901f\u3067\u3059\u3002\u7279\u306b\u3001\u524d\u8ff0\u306e\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\u306f\u6975\u7aef\u306b\u9045\u304f\u306a\u308b\u50be\u5411\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<p>\n    <strong><code>EXPLAIN<\/code><\/strong> \u3092\u4f7f\u3063\u3066\u3001\u5b9f\u884c\u8a08\u753b\u3092\u78ba\u8a8d\u3057\u3001\u30c6\u30fc\u30d6\u30eb\u30b9\u30ad\u30e3\u30f3\u304c\u5897\u3048\u3066\u3044\u306a\u3044\u304b\u78ba\u8a8d\u3059\u308b\u3053\u3068\u304c\u91cd\u8981\u3067\u3059\u3002<\/p>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1aEXPLAIN<\/strong><br \/>\n      SQL\u306e\u5b9f\u884c\u8a08\u753b\u3092\u8868\u793a\u3059\u308b\u30b3\u30de\u30f3\u30c9\u3002\u3069\u306e\u3088\u3046\u306b\u30c6\u30fc\u30d6\u30eb\u3092\u691c\u7d22\u30fb\u7d50\u5408\u3059\u308b\u304b\u3092\u53ef\u8996\u5316\u3057\u3001\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u6539\u5584\u306b\u5f79\u7acb\u3061\u307e\u3059\u3002<\/p>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1a\u30c6\u30fc\u30d6\u30eb\u30b9\u30ad\u30e3\u30f3<\/strong><br \/>\n      \u30c6\u30fc\u30d6\u30eb\u5168\u4f53\u30921\u884c\u305a\u3064\u691c\u7d22\u3059\u308b\u51e6\u7406\u3002\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u304c\u306a\u3044\u5834\u5408\u306b\u767a\u751f\u3057\u3001\u901f\u5ea6\u4f4e\u4e0b\u306e\u539f\u56e0\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<\/blockquote>\n<h3>\u53ef\u8aad\u6027\u30fb\u30ec\u30d3\u30e5\u30fc\u89b3\u70b9\u304b\u3089\u306e\u6bd4\u8f03<\/h3>\n<table>\n<thead>\n<tr>\n<th>\u624b\u6cd5<\/th>\n<th>\u53ef\u8aad\u6027<\/th>\n<th>\u5b9f\u884c\u901f\u5ea6<\/th>\n<th>\u5229\u7528\u30b7\u30fc\u30f3<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>\u30b5\u30d6\u30af\u30a8\u30ea<\/strong><\/td>\n<td>\u4e2d<\/td>\n<td>\u5c0f\u898f\u6a21\u306a\u3089\u25ef\uff0f\u5927\u898f\u6a21\u306f\u00d7<\/td>\n<td>\u6761\u4ef6\u5224\u5b9a\u306b\u4fbf\u5229<\/td>\n<\/tr>\n<tr>\n<td><strong>JOIN<\/strong><\/td>\n<td>\u9ad8<\/td>\n<td>\u6700\u9069\u5316\u3055\u308c\u3084\u3059\u3044<\/td>\n<td>\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u306e\u660e\u793a\u306b\u6709\u52b9<\/td>\n<\/tr>\n<tr>\n<td><strong>CTE<\/strong><\/td>\n<td>\u9ad8<\/td>\n<td>\u518d\u5229\u7528\u6027\u3042\u308a<\/td>\n<td>\u8907\u96d1\u306a\u51e6\u7406\u306e\u5206\u5272\u306b\u6709\u52b9<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3054\u3068\u306e\u6700\u9069\u5316\u5dee<\/h3>\n<ul>\n<li>\n<p><strong>MySQL<\/strong>\uff1a\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u6700\u9069\u5316\u304c\u5f31\u3044\u305f\u3081\u3001<strong>JOIN<\/strong>\u304c\u63a8\u5968\u3055\u308c\u307e\u3059\u3002<\/p>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1aMySQL<\/strong><br \/>\n        \u30aa\u30fc\u30d7\u30f3\u30bd\u30fc\u30b9\u306e\u4ee3\u8868\u7684\u306a\u30ea\u30ec\u30fc\u30b7\u30e7\u30ca\u30eb\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3002\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u6700\u9069\u5316\u304c\u4ed6DB\u3088\u308a\u5f31\u3044\u50be\u5411\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<\/blockquote>\n<\/li>\n<li>\n<p><strong>PostgreSQL<\/strong>\uff1a<strong>CTE<\/strong>\u306e\u6700\u9069\u5316\u306b\u5de5\u592b\u304c\u5fc5\u8981\u3067\u3059\u3002<\/p>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1aPostgreSQL<\/strong><br \/>\n        \u9ad8\u6a5f\u80fd\u306a\u30aa\u30fc\u30d7\u30f3\u30bd\u30fc\u30b9DB\u3002CTE\u3084\u30a6\u30a3\u30f3\u30c9\u30a6\u95a2\u6570\u306e\u30b5\u30dd\u30fc\u30c8\u304c\u5145\u5b9f\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<\/blockquote>\n<\/li>\n<li>\n<p><strong>Oracle<\/strong>\uff1a\u30b5\u30d6\u30af\u30a8\u30ea\u5c55\u958b\u304c\u5f37\u529b\u3067\u3001\u6027\u80fd\u52a3\u5316\u304c\u5c11\u306a\u3044\u5834\u5408\u3082\u3042\u308a\u307e\u3059\u3002<\/p>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1aOracle<\/strong><br \/>\n        \u5546\u7528DB\u306e\u4ee3\u8868\u683c\u3002\u30b5\u30d6\u30af\u30a8\u30ea\u3084\u8907\u96d1\u306aSQL\u306e\u6700\u9069\u5316\u304c\u5f97\u610f\u3067\u3059\u3002<\/p>\n<\/blockquote>\n<\/li>\n<\/ul>\n<hr \/>\n<h2>4. \u30b5\u30d6\u30af\u30a8\u30ea\u306e\u7406\u89e3\u304c\u30ad\u30e3\u30ea\u30a2\u306b\u76f4\u7d50\u3059\u308b\u7406\u7531<\/h2>\n<p>\u5358\u306b\u300c\u52d5\u304fSQL\u3092\u66f8\u3051\u308b\u300d\u3060\u3051\u3067\u306f\u3001\u30a8\u30f3\u30b8\u30cb\u30a2\u3068\u3057\u3066\u306e\u8a55\u4fa1\u306f\u982d\u6253\u3061\u306b\u306a\u308a\u304c\u3061\u3067\u3059\u3002<\/p>\n<p>\u306a\u305c<strong>JOIN<\/strong>\u3092\u9078\u3076\u306e\u304b\u3001\u306a\u305c<strong>CTE<\/strong>\u3092\u4f7f\u3046\u306e\u304b\u3092\u8aac\u660e\u3067\u304d\u308b\u3068\u3001\u8a2d\u8a08\u529b\u304c\u3042\u308b\u3068\u8a55\u4fa1\u3055\u308c\u3001\u5358\u4fa1\u4ea4\u6e09\u3067\u3082\u6709\u5229\u306b\u50cd\u304d\u307e\u3059\u3002<\/p>\n<h3>\u6848\u4ef6\u30df\u30b9\u30de\u30c3\u30c1\u3092\u907f\u3051\u308b\u305f\u3081\u306e\u30b9\u30ad\u30eb\u306e\u898b\u305b\u65b9<\/h3>\n<ul>\n<li>\n<p>\u30ec\u30b8\u30e5\u30e1\u306b\u300c\u5b9f\u884c\u8a08\u753b\u3092\u8003\u616e\u3057\u305fSQL\u6700\u9069\u5316\u7d4c\u9a13\u300d\u3068\u8a18\u8f09\u3059\u308b<\/p>\n<\/li>\n<li>\n<p>\u30b3\u30fc\u30c9\u30ec\u30d3\u30e5\u30fc\u3067\u300c\u4fdd\u5b88\u6027\u3092\u91cd\u8996\u3057\u305f\u8a2d\u8a08\u65b9\u91dd\u300d\u3092\u8a00\u8a9e\u5316\u3059\u308b<\/p>\n<\/li>\n<li>\n<p>\u300c\u5358\u4fa1\u516c\u958b\u578bSES\u300d\u3084\u300c\u6848\u4ef6\u9078\u5b9a\u53ef\u300d\u306e\u4f01\u696d\u306b\u30a2\u30d4\u30fc\u30eb\u3059\u308b<\/p>\n<\/li>\n<\/ul>\n<p><strong>\u30b5\u30d6\u30af\u30a8\u30ea<\/strong>\u306f\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306e\u8a2d\u8a08\u601d\u60f3\u306e\u57fa\u790e\u3067\u3059\u3002\u305d\u306e\u7406\u89e3\u306f\u3001\u8a55\u4fa1\u57fa\u6e96\u306b\u306a\u308a\u3084\u3059\u304f\u3001\u5c06\u6765<strong>\u30a2\u30fc\u30ad\u30c6\u30af\u30c8<\/strong>\u5019\u88dc\u3092\u76ee\u6307\u3059\u4e0a\u3067\u907f\u3051\u3066\u901a\u308c\u306a\u3044\u30dd\u30a4\u30f3\u30c8\u3068\u8a00\u3048\u307e\u3059\u3002<\/p>\n<hr \/>\n<h2>\u307e\u3068\u3081\uff1a\u4eca\u65e5\u304b\u3089\u3067\u304d\u308b\u5b9f\u8df5\u30b9\u30c6\u30c3\u30d7<\/h2>\n<p>\u6700\u5f8c\u306b\u3001<strong>\u30b5\u30d6\u30af\u30a8\u30ea<\/strong>\u3092\u4f7f\u3046\u304b\u907f\u3051\u308b\u304b\u306e\u7c21\u5358\u306a\u5224\u65ad\u30d5\u30ed\u30fc\u3068\u3001\u5b66\u3093\u3060\u77e5\u8b58\u3092\u30ad\u30e3\u30ea\u30a2\u306b\u6d3b\u304b\u3059\u305f\u3081\u306e\u30c1\u30a7\u30c3\u30af\u30ea\u30b9\u30c8\u3092\u307e\u3068\u3081\u307e\u3059\u3002<\/p>\n<p>\uff08SES\u30a8\u30f3\u30b8\u30cb\u30a2\u306e\u30ad\u30e3\u30ea\u30a2\u6226\u7565\u306b\u3064\u3044\u3066\u306f<a href=\"https:\/\/route-zero.com\/recruit\/route\/1534\/\">SES\u30dd\u30fc\u30c8\u30d5\u30a9\u30ea\u30aa\u5b8c\u5168\u30ac\u30a4\u30c9\uff5c5\u5e74\u5f8c\u3082\u9078\u3070\u308c\u308b\u30a8\u30f3\u30b8\u30cb\u30a2\u306e\u30ad\u30e3\u30ea\u30a2\u6226\u7565\u3068\u4f5c\u308a\u65b9<\/a>\u3092\u3054\u53c2\u7167\u304f\u3060\u3055\u3044\uff09<\/p>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1a\u30a6\u30a3\u30f3\u30c9\u30a6\u95a2\u6570<\/strong><br \/>\n    \u96c6\u8a08\u3084\u9806\u4f4d\u4ed8\u3051\u306a\u3069\u3001\u8907\u6570\u884c\u3092\u307e\u305f\u3044\u3060\u8a08\u7b97\u3092\u884c\u3046SQL\u306e\u95a2\u6570\u3002CTE\u3084\u30b5\u30d6\u30af\u30a8\u30ea\u3068\u7d44\u307f\u5408\u308f\u305b\u3066\u4f7f\u3046\u3053\u3068\u304c\u591a\u3044\u3067\u3059\u3002<\/p>\n<\/blockquote>\n<h3>\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u4f7f\u3046\uff0f\u907f\u3051\u308b\u5224\u65ad\u30d5\u30ed\u30fc<\/h3>\n<ol>\n<li>\n<p><strong>\u5c0f\u898f\u6a21\u30c7\u30fc\u30bf<\/strong> \u2192 \u30b5\u30d6\u30af\u30a8\u30ea\u3092\u4f7f\u3063\u3066\u3082\u554f\u984c\u306a\u3044\u30b1\u30fc\u30b9\u304c\u591a\u3044<\/p>\n<\/li>\n<li>\n<p><strong>\u5927\u898f\u6a21\u30c7\u30fc\u30bf<\/strong> \u2192 <strong>JOIN<\/strong>\u3084<strong>CTE<\/strong>\u3092\u512a\u5148\u3059\u308b<\/p>\n<\/li>\n<li>\n<p><strong>\u8aad\u307f\u3084\u3059\u3055\u512a\u5148<\/strong> \u2192 <strong>JOIN<\/strong>\u3084<strong>CTE<\/strong>\u304c\u63a8\u5968\u3055\u308c\u308b<\/p>\n<\/li>\n<\/ol>\n<h3>\u5b66\u3073\u3092\u30ad\u30e3\u30ea\u30a2\u8a55\u4fa1\u306b\u6d3b\u304b\u3059\u30c1\u30a7\u30c3\u30af\u30ea\u30b9\u30c8<\/h3>\n<ul>\n<li>\n<p>&#x2705; \u5b9f\u884c\u8a08\u753b\uff08<strong>EXPLAIN<\/strong>\uff09\u3092\u8aad\u3081\u307e\u3059\u304b\uff1f<\/p>\n<\/li>\n<li>\n<p>&#x2705; <strong>JOIN<\/strong>\u3084<strong>CTE<\/strong>\u3067\u66f8\u304d\u63db\u3048\u3089\u308c\u307e\u3059\u304b\uff1f<\/p>\n<\/li>\n<li>\n<p>&#x2705; \u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3054\u3068\u306e\u6700\u9069\u5316\u7279\u6027\u3092\u7406\u89e3\u3057\u3066\u3044\u307e\u3059\u304b\uff1f<\/p>\n<\/li>\n<li>\n<p>&#x2705; \u8a2d\u8a08\u610f\u56f3\u3092\u8a00\u8a9e\u5316\u3067\u304d\u307e\u3059\u304b\uff1f<\/p>\n<\/li>\n<\/ul>\n<p><\/p>\n<h3>FAQ\uff1a\u3088\u304f\u3042\u308b\u7591\u554f<\/h3>\n<ul>\n<li>\n<p><strong>Q. SQL\u30b5\u30d6\u30af\u30a8\u30ea\u306fJOIN\u3088\u308a\u9045\u3044\u306e\uff1f\u3069\u3093\u306a\u5834\u5408\u306b\uff1f<\/strong><br \/><strong>A.<\/strong> \u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\u3067\u9855\u8457\u3067\u3059\u3002\u975e\u76f8\u95a2\u3084<strong>\u30b9\u30ab\u30e9\u30fc\u30b5\u30d6\u30af\u30a8\u30ea<\/strong>\u3067\u306f\u305d\u3053\u307e\u3067\u5927\u304d\u306a\u5dee\u306f\u51fa\u307e\u305b\u3093\u3002<\/p>\n<blockquote>\n<p><strong>\u7528\u8a9e\u89e3\u8aac\uff1a\u30b9\u30ab\u30e9\u30fc\u30b5\u30d6\u30af\u30a8\u30ea\u30fb\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea<\/strong><br \/>\n        \u30b9\u30ab\u30e9\u30fc\u30b5\u30d6\u30af\u30a8\u30ea\u306f\u5358\u4e00\u5024\u3092\u8fd4\u3059\u3082\u306e\u3001\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\u306f\u5916\u5074\u306e\u5024\u3092\u53c2\u7167\u3057\u7e70\u308a\u8fd4\u3057\u5b9f\u884c\u3055\u308c\u308b\u3082\u306e\u3067\u3059\u3002<\/p>\n<\/blockquote>\n<\/li>\n<li>\n<p><strong>Q. \u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\u3068\u975e\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u9055\u3044\u306f\uff1f<\/strong><br \/><strong>A.<\/strong> \u5916\u5074\u306e\u30af\u30a8\u30ea\u306e\u5024\u3092\u53c2\u7167\u3059\u308b\u304b\u3069\u3046\u304b\u304c\u5927\u304d\u306a\u9055\u3044\u3067\u3059\u3002<\/p>\n<\/li>\n<li>\n<p><strong>Q. \u30b5\u30d6\u30af\u30a8\u30ea\u306f\u3069\u306e\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3067\u3082\u540c\u3058\u52d5\u304d\uff1f<\/strong><br \/><strong>A.<\/strong> \u5b9f\u88c5\u306b\u9055\u3044\u304c\u3042\u308a\u307e\u3059\u3002<strong>MySQL<\/strong>\u306f\u5f31\u304f\u3001<strong>Oracle<\/strong>\u306f\u5f37\u529b\u3067\u3059\u3002<\/p>\n<\/li>\n<li>\n<p><strong>Q. \u30b5\u30d6\u30af\u30a8\u30ea\u3092\u4f7f\u3044\u3059\u304e\u308b\u3068\u30ec\u30d3\u30e5\u30fc\u3067\u6307\u6458\u3055\u308c\u308b\u306e\u306f\u306a\u305c\uff1f<\/strong><br \/><strong>A.<\/strong> \u53ef\u8aad\u6027\u3084\u4fdd\u5b88\u6027\u3092\u640d\u306a\u3046\u53ef\u80fd\u6027\u304c\u3042\u308b\u305f\u3081\u3067\u3059\u3002<\/p>\n<\/li>\n<li>\n<p><strong>Q. \u30b5\u30d6\u30af\u30a8\u30ea\u3088\u308aCTE\u3084\u30a6\u30a3\u30f3\u30c9\u30a6\u95a2\u6570\u3092\u9078\u3076\u3079\u304d\u30b1\u30fc\u30b9\u306f\uff1f<\/strong><br \/><strong>A.<\/strong> \u8907\u96d1\u306a\u96c6\u8a08\u3084\u3001\u8907\u6570\u306e\u5834\u6240\u3067\u518d\u5229\u7528\u3057\u305f\u3044\u51e6\u7406\u304c\u3042\u308b\u3068\u304d\u3067\u3059\u3002<\/p>\n<\/li>\n<li>\n<p><strong>Q. \u30b5\u30d6\u30af\u30a8\u30ea\u306e\u77e5\u8b58\u306f\u30ad\u30e3\u30ea\u30a2\u8a55\u4fa1\u306b\u3069\u3046\u5f71\u97ff\u3059\u308b\uff1f<\/strong><br \/><strong>A.<\/strong> \u8a2d\u8a08\u601d\u60f3\u3092\u7406\u89e3\u3057\u3066\u3044\u308b\u3068\u8a55\u4fa1\u304c\u4e0a\u304c\u308a\u3001\u3088\u308a\u4e0a\u6d41\u306e\u4ed5\u4e8b\u3092\u4efb\u3055\u308c\u3084\u3059\u304f\u306a\u308a\u307e\u3059\u3002<\/p>\n<\/li>\n<\/ul>\n<hr \/>\n<h2>\u6700\u5f8c\u306b<\/h2>\n<p><strong>SQL\u30b5\u30d6\u30af\u30a8\u30ea<\/strong>\u306f\u975e\u5e38\u306b\u4fbf\u5229\u3067\u3059\u304c\u3001<strong>\u4e07\u80fd\u3067\u306f\u306a\u304f\u300c\u3069\u306e\u5834\u9762\u3067\u4f7f\u3046\u304b\u300d\u3092\u5224\u65ad\u3059\u308b\u529b\u304c\u91cd\u8981<\/strong>\u3067\u3059\u3002<\/p>\n<p>\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u591a\u7528\u3059\u308c\u3070\u901f\u5ea6\u4f4e\u4e0b\u3092\u62db\u304d\u3001\u30ec\u30d3\u30e5\u30fc\u3067\u6307\u6458\u3055\u308c\u308b\u3053\u3068\u3082\u3042\u308a\u307e\u3059\u3002<strong>JOIN<\/strong>\u3084<strong>CTE<\/strong>\u3068\u306e\u9055\u3044\u3092\u7406\u89e3\u3057\u3001\u5b9f\u884c\u8a08\u753b\u3092\u610f\u8b58\u3067\u304d\u308b\u3053\u3068\u306f\u3001\u30a8\u30f3\u30b8\u30cb\u30a2\u3068\u3057\u3066\u306e\u8a55\u4fa1\u3084\u6848\u4ef6\u9078\u5b9a\u306e\u81ea\u7531\u5ea6\u306b\u3064\u306a\u304c\u308a\u307e\u3059\u3002<\/p>\n<p>\u7279\u306bSES\u5e38\u99d0\u306e\u73fe\u5834\u3067\u306f\u3001\u8a2d\u8a08\u601d\u60f3\u3092\u8aac\u660e\u3067\u304d\u308b\u4eba\u6750\u304c\u8a55\u4fa1\u3055\u308c\u3084\u3059\u304f\u3001\u30ad\u30e3\u30ea\u30a2\u306e\u9078\u629e\u80a2\u3082\u5e83\u304c\u308a\u307e\u3059\u3002<\/p>\n<p><\/p>\n<p>\u305c\u3072\u4eca\u65e5\u5b66\u3093\u3060\u77e5\u8b58\u3092\u81ea\u5206\u306e\u30b3\u30fc\u30c9\u3084\u30ec\u30d3\u30e5\u30fc\u306b\u6d3b\u304b\u3057\u3001\u300c\u52d5\u3051\u3070\u3044\u3044\u300d\u304b\u3089\u300c\u7d0d\u5f97\u3067\u304d\u308b\u8a2d\u8a08\u300d\u3078\u3068\u4e00\u6b69\u9032\u3093\u3067\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n<\/div>\n","protected":false},"featured_media":1596,"template":"","_links":{"self":[{"href":"https:\/\/route-zero.com\/recruit\/wp-json\/wp\/v2\/route\/1594"}],"collection":[{"href":"https:\/\/route-zero.com\/recruit\/wp-json\/wp\/v2\/route"}],"about":[{"href":"https:\/\/route-zero.com\/recruit\/wp-json\/wp\/v2\/types\/route"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/route-zero.com\/recruit\/wp-json\/wp\/v2\/media\/1596"}],"wp:attachment":[{"href":"https:\/\/route-zero.com\/recruit\/wp-json\/wp\/v2\/media?parent=1594"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}