SQL\u5fdc\u7528Tips\u30c9\u30e9\u30d5\u30c8<\/title><\/p>\n<style>\n body { font-family: Meiryo, 'Hiragino Kaku Gothic ProN', 'MS PGothic', sans-serif; line-height: 1.8; color: #333; }\n h2 { font-size: 1.5em; color: #1a0dab; border-bottom: 2px solid #1a0dab; padding-bottom: 0.5em; margin-top: 2em; margin-bottom: 1em; }\n h3 { font-size: 1.2em; color: #333; border-left: 5px solid #1a0dab; padding-left: 0.8em; margin-top: 1.5em; margin-bottom: 1em; }\n p, li { font-size: 1em; }\n table { border-collapse: collapse; width: 100%; margin: 1.5em 0; border: 1px solid #ccc; }\n th, td { border: 1px solid #ccc; padding: 0.8em; text-align: left; }\n th { background-color: #f2f2f2; font-weight: bold; }\n pre { background-color: #f5f5f5; padding: 1em; border: 1px solid #ccc; border-radius: 4px; white-space: pre-wrap; word-wrap: break-word; }\n code { font-family: 'Courier New', Courier, monospace; }\n .mermaid-diagram { text-align: center; padding: 1em; border: 1px dashed #aaa; margin: 1.5em 0; background-color: #fafafa; }\n .mermaid-diagram pre { background-color: #fff; text-align: left; }\n <\/style>\n<p><\/head><br \/>\n<body><\/p>\n<p>SQL\u306e\u57fa\u672c\u7684\u306a\u66f8\u304d\u65b9\u3092\u30de\u30b9\u30bf\u30fc\u3057\u305f\u30a8\u30f3\u30b8\u30cb\u30a2\u304c\u3001\u6b21\u306a\u308b\u30b9\u30c6\u30c3\u30d7\u3068\u3057\u3066\u5411\u304d\u5408\u3046\u306e\u304c\u300c\u5b9f\u52d9\u3067\u901a\u7528\u3059\u308bSQL\u300d\u306e\u58c1\u3067\u3059\u3002\u30c6\u30b9\u30c8\u74b0\u5883\u3067\u306f\u554f\u984c\u306a\u304f\u52d5\u3044\u305f\u30af\u30a8\u30ea\u304c\u3001\u672c\u756a\u74b0\u5883\u306e\u5927\u91cf\u30c7\u30fc\u30bf\u3084\u540c\u6642\u30a2\u30af\u30bb\u30b9\u306b\u3088\u3063\u3066\u6df1\u523b\u306a\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u4f4e\u4e0b\u3092\u5f15\u304d\u8d77\u3053\u3057\u305f\u308a\u3001\u610f\u56f3\u3057\u306a\u3044\u30c7\u30fc\u30bf\u4e0d\u6574\u5408\u3092\u62db\u3044\u305f\u308a\u3059\u308b\u30b1\u30fc\u30b9\u306f\u5c11\u306a\u304f\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n<p>\u3053\u306e\u554f\u984c\u306e\u6839\u5e95\u306b\u3042\u308b\u306e\u304c\u3001\u300c\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u300d\u300c\u30ed\u30c3\u30af\u7af6\u5408\u300d\u300c\u30c7\u30fc\u30bf\u6574\u5408\u6027\u300d\u3068\u3044\u30463\u3064\u306e\u91cd\u8981\u306a\u8996\u70b9\u3067\u3059\u3002\u3053\u308c\u3089\u306f\u5358\u306a\u308b\u77e5\u8b58\u3067\u306f\u306a\u304f\u3001\u5b89\u5b9a\u3057\u305f\u30b7\u30b9\u30c6\u30e0\u3092\u652f\u3048\u308b\u305f\u3081\u306e\u5b9f\u8df5\u7684\u306a\u6280\u8853\u3068\u8a00\u3048\u307e\u3059\u3002\u7279\u306b\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u30b9\u30da\u30b9\u30da\u30b7\u30e3\u30ea\u30b9\u30c8\u8a66\u9a13\u3084\u5fdc\u7528\u60c5\u5831\u6280\u8853\u8005\u8a66\u9a13\u306e\u5348\u5f8c\u554f\u984c\u3067\u306f\u3001\u3053\u308c\u3089\u306e\u5fdc\u7528\u529b\u3092\u554f\u3046\u8a2d\u554f\u304c\u983b\u51fa\u3057\u307e\u3059\u3002<\/p>\n<p>\u672c\u8a18\u4e8b\u3067\u306f\u3001SQL\u306e\u5fdc\u7528\u529b\u3092\u9ad8\u3081\u305f\u3044\u30a8\u30f3\u30b8\u30cb\u30a2\u306b\u5411\u3051\u3066\u3001\u5b9f\u52d9\u3067\u983b\u7e41\u306b\u76f4\u9762\u3059\u308b\u4e0a\u8a183\u3064\u306e\u30c6\u30fc\u30de\u306b\u7126\u70b9\u3092\u5f53\u3066\u3066\u89e3\u8aac\u3057\u307e\u3059\u3002\u5b9f\u884c\u8a08\u753b\u306e\u8aad\u307f\u89e3\u304d\u65b9\u304b\u3089\u3001\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u3092\u56de\u907f\u3059\u308b\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u8a2d\u8a08\u3001\u30c7\u30fc\u30bf\u306e\u77db\u76fe\u3092\u9632\u3050\u5236\u7d04\u306e\u6d3b\u7528\u307e\u3067\u3001\u5177\u4f53\u7684\u306a\u30b3\u30fc\u30c9\u4f8b\u3084\u56f3\u89e3\u3092\u4ea4\u3048\u306a\u304c\u3089\u3001\u7406\u8ad6\u3068\u5b9f\u8df5\u3092\u3064\u306a\u3050\u77e5\u8b58\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002\u3053\u306e\u8a18\u4e8b\u3092\u8aad\u307f\u7d42\u3048\u308b\u9803\u306b\u306f\u3001\u3042\u306a\u305f\u306eSQL\u306f\u4e00\u6bb5\u3068\u6d17\u7df4\u3055\u308c\u3001\u5805\u7262\u306a\u3082\u306e\u306b\u306a\u3063\u3066\u3044\u308b\u306f\u305a\u3067\u3059\u3002<\/p>\n<h2>SQL\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0\u306e\u7b2c\u4e00\u6b69\u2502\u5b9f\u884c\u8a08\u753b\u306e\u89e3\u8aad\u3068\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u6226\u7565<\/h2>\n<p>\u3069\u3093\u306a\u306b\u512a\u308c\u305f\u6a5f\u80fd\u3092\u6301\u3064\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u3067\u3082\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3078\u306e\u554f\u3044\u5408\u308f\u305b\uff08\u30af\u30a8\u30ea\uff09\u304c\u9045\u3051\u308c\u3070\u3001\u30e6\u30fc\u30b6\u30fc\u4f53\u9a13\u306f\u8457\u3057\u304f\u640d\u306a\u308f\u308c\u307e\u3059\u3002SQL\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0\u306f\u3001\u5fdc\u7b54\u6027\u306e\u9ad8\u3044\u30b7\u30b9\u30c6\u30e0\u3092\u7dad\u6301\u3059\u308b\u305f\u3081\u306e\u5fc5\u9808\u30b9\u30ad\u30eb\u3067\u3059\u3002\u3053\u3053\u3067\u306f\u3001\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u4f4e\u4e0b\u306e\u5178\u578b\u7684\u306a\u539f\u56e0\u3092\u7a81\u304d\u6b62\u3081\u3001\u305d\u306e\u5bfe\u7b56\u306e\u57fa\u672c\u3068\u306a\u308b\u300c\u5b9f\u884c\u8a08\u753b\u300d\u3068\u300c\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u300d\u306b\u3064\u3044\u3066\u89e3\u8aac\u3057\u307e\u3059\u3002<\/p>\n<h3>\u306a\u305cSQL\u306f\u9045\u304f\u306a\u308b\u306e\u304b\uff1f \u5178\u578b\u7684\u306a\u539f\u56e0<\/h3>\n<p>SQL\u304c\u9045\u304f\u306a\u308b\u539f\u56e0\u306f\u69d8\u3005\u3067\u3059\u304c\u3001\u7279\u306b\u983b\u51fa\u3059\u308b\u30d1\u30bf\u30fc\u30f3\u306f\u4ee5\u4e0b\u306e\u901a\u308a\u3067\u3059\u3002\u3053\u308c\u3089\u306f\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u30b9\u30da\u30b7\u30e3\u30ea\u30b9\u30c8\u8a66\u9a13\u306e\u5348\u5f8c\u554f\u984c\u3067\u3082\u983b\u7e41\u306b\u554f\u308f\u308c\u308b\u8ad6\u70b9\u3067\u3059\u3002<\/p>\n<table>\n<thead>\n<tr>\n<th>\u539f\u56e0<\/th>\n<th>\u89e3\u8aac<\/th>\n<th>\u5b9f\u52d9\u3067\u306e\u4f8b\u3048<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>\u30d5\u30eb\u30c6\u30fc\u30d6\u30eb\u30b9\u30ad\u30e3\u30f3<\/strong><\/td>\n<td>\u76ee\u7684\u306e\u30c7\u30fc\u30bf\u3092\u63a2\u3059\u305f\u3081\u306b\u3001\u30c6\u30fc\u30d6\u30eb\u306e\u5168\u30ec\u30b3\u30fc\u30c9\u3092\u6700\u521d\u304b\u3089\u6700\u5f8c\u307e\u3067\u30b9\u30ad\u30e3\u30f3\u3057\u3066\u3057\u307e\u3046\u3053\u3068\u3002\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u304c\u9069\u5207\u306b\u5229\u7528\u3055\u308c\u3066\u3044\u306a\u3044\u5834\u5408\u306b\u767a\u751f\u3057\u307e\u3059\u3002<\/td>\n<td>\u767e\u79d1\u4e8b\u5178\u3067\u8abf\u3079\u7269\u3092\u3059\u308b\u306e\u306b\u3001\u76ee\u6b21\u3084\u7d22\u5f15\u3092\u4f7f\u308f\u305a1\u30da\u30fc\u30b8\u76ee\u304b\u3089\u9806\u306b\u63a2\u3059\u3088\u3046\u306a\u72b6\u614b\u3002<\/td>\n<\/tr>\n<tr>\n<td><strong>\u4e0d\u9069\u5207\u306aJOIN<\/strong><\/td>\n<td>\u5de8\u5927\u306a\u30c6\u30fc\u30d6\u30eb\u540c\u58eb\u3092\u975e\u52b9\u7387\u306a\u6761\u4ef6\u3067\u7d50\u5408\u3057\u305f\u308a\u3001\u5fc5\u8981\u4ee5\u4e0a\u306b\u591a\u304f\u306e\u30c6\u30fc\u30d6\u30eb\u3092\u7d50\u5408\u3057\u305f\u308a\u3059\u308b\u3053\u3068\u3067\u3001\u51e6\u7406\u30b3\u30b9\u30c8\u304c\u7206\u767a\u7684\u306b\u5897\u52a0\u3057\u307e\u3059\u3002<\/td>\n<td>\u8907\u6570\u306e\u540d\u7c3f\u3092\u7a81\u5408\u3059\u308b\u969b\u3001\u5171\u901a\u306eID\u3092\u4f7f\u308f\u305a\u306b\u5168\u54e1\u306e\u30d7\u30ed\u30d5\u30a3\u30fc\u30eb\u3092\u4e00\u3064\u3072\u3068\u3064\u898b\u6bd4\u3079\u3066\u3044\u308b\u3088\u3046\u306a\u72b6\u614b\u3002<\/td>\n<\/tr>\n<tr>\n<td><strong>WHERE\u53e5\u306e\u975e\u52b9\u7387\u306a\u6761\u4ef6<\/strong><\/td>\n<td><code>WHERE a + 1 = 10<\/code> \u306e\u3088\u3046\u306b\u3001\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u304c\u8a2d\u5b9a\u3055\u308c\u305f\u5217\uff08\u3053\u3053\u3067\u306f <code>a<\/code>\uff09\u306b\u76f4\u63a5\u8a08\u7b97\u3084\u95a2\u6570\u3092\u9069\u7528\u3059\u308b\u3068\u3001\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u304c\u5229\u7528\u3067\u304d\u306a\u304f\u306a\u308a\u307e\u3059\u3002<\/td>\n<td>\u7d22\u5f15\u306b\u300c\u7530\u4e2d\u300d\u3067\u8f09\u3063\u3066\u3044\u308b\u4eba\u3092\u63a2\u3059\u306e\u306b\u3001\u308f\u3056\u308f\u3056\u5168\u54e1\u306b\u300c\u82d7\u5b57\u306f\u4f55\u3067\u3059\u304b\uff1f\u300d\u3068\u805e\u3044\u3066\u56de\u308b\u3088\u3046\u306a\u3082\u306e\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>\u30dc\u30c8\u30eb\u30cd\u30c3\u30af\u3092\u898b\u3064\u3051\u308b\u7f85\u91dd\u76e4\u300c\u5b9f\u884c\u8a08\u753b\u300d<\/h3>\n<p>\u300c\u5b9f\u884c\u8a08\u753b\u300d\u3068\u306f\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u304cSQL\u3092\u53d7\u3051\u53d6\u3063\u305f\u969b\u306b\u3001\u300c\u3069\u306e\u3088\u3046\u306a\u624b\u9806\u3067\u30c7\u30fc\u30bf\u306b\u30a2\u30af\u30bb\u30b9\u3057\u3001\u7d50\u679c\u3092\u8fd4\u3059\u304b\u300d\u3068\u3044\u3046\u5185\u90e8\u7684\u306a\u51e6\u7406\u8a08\u753b\u306e\u3053\u3068\u3067\u3059\u3002SQL\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0\u306f\u3001\u307e\u305a\u3053\u306e\u5b9f\u884c\u8a08\u753b\u3092\u8aad\u307f\u89e3\u304d\u3001\u3069\u3053\u306b\u7121\u99c4\u304c\u3042\u308b\u306e\u304b\uff08\u30dc\u30c8\u30eb\u30cd\u30c3\u30af\uff09\u3092\u7279\u5b9a\u3059\u308b\u3053\u3068\u304b\u3089\u59cb\u307e\u308a\u307e\u3059\u3002<\/p>\n<p>\u4f8b\u3048\u3070\u3001<code>EXPLAIN<\/code> \u3068\u3044\u3046\u30b3\u30de\u30f3\u30c9\u3092\u4f7f\u3046\u3053\u3068\u3067\u3001\u3053\u306e\u5b9f\u884c\u8a08\u753b\u3092\u78ba\u8a8d\u3067\u304d\u307e\u3059\u3002<\/p>\n<p><strong>\u3010\u30b3\u30fc\u30c9\u4f8b: \u30e6\u30fc\u30b6\u30fc\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u7279\u5b9a\u306eemail\u3092\u6301\u3064\u30e6\u30fc\u30b6\u30fc\u3092\u691c\u7d22\u3011<\/strong><\/p>\n<pre><code>EXPLAIN SELECT user_id, user_name\nFROM users\nWHERE email = 'test.user@example.com';<\/code><\/pre>\n<p>\u3053\u306e\u7d50\u679c\u3092\u898b\u3066\u3001\u300c<code>type: ALL<\/code>\uff08\u30d5\u30eb\u30c6\u30fc\u30d6\u30eb\u30b9\u30ad\u30e3\u30f3\uff09\u306b\u306a\u3063\u3066\u3044\u306a\u3044\u304b\u300d\u300c<code>key<\/code>\uff08\u4f7f\u7528\u3059\u308b\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\uff09\u304c\u610f\u56f3\u3057\u305f\u3082\u306e\u306b\u306a\u3063\u3066\u3044\u308b\u304b\u300d\u306a\u3069\u3092\u78ba\u8a8d\u3057\u3001\u554f\u984c\u70b9\u3092\u7279\u5b9a\u3057\u307e\u3059\u3002\u5b9f\u884c\u8a08\u753b\u306f\u3001\u307e\u308b\u3067\u30ab\u30fc\u30ca\u30d3\u304c\u6700\u9069\u306a\u30eb\u30fc\u30c8\u3092\u63d0\u793a\u3057\u3066\u304f\u308c\u308b\u3088\u3046\u306b\u3001SQL\u306e\u51e6\u7406\u7d4c\u8def\u3092\u53ef\u8996\u5316\u3057\u3066\u304f\u308c\u308b\u5f37\u529b\u306a\u30c4\u30fc\u30eb\u306a\u306e\u3067\u3059\u3002<\/p>\n<h3>\u57fa\u672c\u306b\u3057\u3066\u6700\u5f37\u306e\u6b66\u5668\u300c\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u300d<\/h3>\n<p>\u5b9f\u884c\u8a08\u753b\u3092\u5206\u6790\u3057\u3066\u30d5\u30eb\u30c6\u30fc\u30d6\u30eb\u30b9\u30ad\u30e3\u30f3\u306a\u3069\u306e\u554f\u984c\u304c\u898b\u3064\u304b\u3063\u305f\u5834\u5408\u3001\u6700\u3082\u57fa\u672c\u7684\u306a\u89e3\u6c7a\u7b56\u304c\u300c\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u300d\u306e\u4f5c\u6210\u3067\u3059\u3002\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306f\u3001\u7279\u5b9a\u306e\u5217\u306e\u5024\u3092\u30ad\u30fc\u3068\u3057\u3066\u3001\u5bfe\u5fdc\u3059\u308b\u30ec\u30b3\u30fc\u30c9\u306e\u4f4d\u7f6e\u60c5\u5831\u3092\u4fdd\u6301\u3059\u308b\u4ed5\u7d44\u307f\u3067\u3001\u672c\u306e\u5dfb\u672b\u306b\u3042\u308b\u300c\u7d22\u5f15\u300d\u306b\u4f8b\u3048\u3089\u308c\u307e\u3059\u3002<\/p>\n<div class=\"mermaid-diagram\">\n<p><strong>[\u56f3\u89e3: \u30d5\u30eb\u30c6\u30fc\u30d6\u30eb\u30b9\u30ad\u30e3\u30f3\u3068\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u30b9\u30ad\u30e3\u30f3\u306e\u6982\u5ff5\u6bd4\u8f03]<\/strong><\/p>\n<pre><code>graph TD\n subgraph \u30d5\u30eb\u30c6\u30fc\u30d6\u30eb\u30b9\u30ad\u30e3\u30f3\uff08\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306a\u3057\uff09\n A[\u691c\u7d22\u958b\u59cb] --> B{\u30c7\u30fc\u30bf\u30d6\u30ed\u30c3\u30af1};\n B --> C{\u30c7\u30fc\u30bf\u30d6\u30ed\u30c3\u30af2};\n C --> D{...};\n D --> E{\u30c7\u30fc\u30bf\u30d6\u30ed\u30c3\u30afN};\n E --> F[\u76ee\u7684\u306e\u30c7\u30fc\u30bf\u767a\u898b or \u898b\u3064\u304b\u3089\u306a\u3044];\n end\n\n subgraph \u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u30b9\u30ad\u30e3\u30f3\n G[\u691c\u7d22\u958b\u59cb] --> H{\u30a4\u30f3\u30c7\u30c3\u30af\u30b9};\n H -- \u76ee\u7684\u306e\u30c7\u30fc\u30bf\u306e\u4f4d\u7f6e\u60c5\u5831\u3092\u7279\u5b9a --> I{\u5bfe\u8c61\u30c7\u30fc\u30bf\u30d6\u30ed\u30c3\u30af};\n I --> J[\u76ee\u7684\u306e\u30c7\u30fc\u30bf\u767a\u898b];\n end<\/code><\/pre>\n<\/div>\n<p>\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306f <code>WHERE<\/code> \u53e5\u3067\u306e\u7d5e\u308a\u8fbc\u307f\u3084 <code>JOIN<\/code> \u306e\u7d50\u5408\u6761\u4ef6\u3001<code>ORDER BY<\/code> \u3067\u306e\u30bd\u30fc\u30c8\u51e6\u7406\u3092\u5287\u7684\u306b\u9ad8\u901f\u5316\u3057\u307e\u3059\u3002\u305f\u3060\u3057\u3001\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3092\u7121\u95c7\u306b\u8ffd\u52a0\u3059\u308b\u3068\u3001\u30c7\u30fc\u30bf\u306e\u767b\u9332\u30fb\u66f4\u65b0\u30fb\u524a\u9664\uff08<code>INSERT<\/code>, <code>UPDATE<\/code>, <code>DELETE<\/code>\uff09\u6642\u306b\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u66f4\u65b0\u30b3\u30b9\u30c8\u304c\u767a\u751f\u3057\u3001\u9006\u306b\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u4f4e\u4e0b\u3059\u308b\u3053\u3068\u3082\u3042\u308a\u307e\u3059\u3002\u3069\u306e\u5217\u306b\u3001\u3069\u306e\u3088\u3046\u306a\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3092\u4f5c\u6210\u3059\u308b\u304b\u306e\u8a2d\u8a08\u304c\u975e\u5e38\u306b\u91cd\u8981\u3067\u3059\u3002<\/p>\n<h2>\u540c\u6642\u5b9f\u884c\u5236\u5fa1\u306e\u6838\u5fc3\uff01\u30ed\u30c3\u30af\u7af6\u5408\u3068\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u3092\u56de\u907f\u3059\u308bSQL\u6226\u7565<\/h2>\n<p>\u8907\u6570\u306e\u30e6\u30fc\u30b6\u30fc\u304c\u540c\u6642\u306b\u30b7\u30b9\u30c6\u30e0\u3092\u5229\u7528\u3059\u308b\u74b0\u5883\u3067\u306f\u3001\u300c\u8ab0\u304b\u304c\u30c7\u30fc\u30bf\u3092\u66f4\u65b0\u3057\u3066\u3044\u308b\u6700\u4e2d\u306b\u3001\u5225\u306e\u8ab0\u304b\u304c\u305d\u306e\u30c7\u30fc\u30bf\u3092\u8aad\u307f\u66f8\u304d\u3057\u3088\u3046\u3068\u3059\u308b\u300d\u3068\u3044\u3046\u72b6\u6cc1\u304c\u5e38\u306b\u767a\u751f\u3057\u307e\u3059\u3002\u3053\u306e\u3088\u3046\u306a\u540c\u6642\u5b9f\u884c\u3092\u9069\u5207\u306b\u5236\u5fa1\u3057\u306a\u3044\u3068\u3001\u30c7\u30fc\u30bf\u304c\u77db\u76fe\u3057\u305f\u72b6\u614b\u306b\u9665\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u306e\u5236\u5fa1\u306e\u6838\u5fc3\u3068\u306a\u308b\u306e\u304c\u300c\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u300d\u3068\u300c\u30ed\u30c3\u30af\u300d\u306e\u6982\u5ff5\u3067\u3059\u3002<\/p>\n<h3>\u306a\u305c\u30ed\u30c3\u30af\u304c\u5fc5\u8981\u306a\u306e\u304b\uff1f\uff1a\u5171\u6709\u30ed\u30c3\u30af\u3068\u6392\u4ed6\u30ed\u30c3\u30af<\/h3>\n<p>\u30ed\u30c3\u30af\u3068\u306f\u3001\u7279\u5b9a\u306e\u30ea\u30bd\u30fc\u30b9\uff08\u30c6\u30fc\u30d6\u30eb\u3084\u884c\uff09\u306b\u4ed6\u306e\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u304c\u30a2\u30af\u30bb\u30b9\u3059\u308b\u306e\u3092\u5236\u9650\u3059\u308b\u4ed5\u7d44\u307f\u3067\u3059\u3002\u6700\u3082\u57fa\u672c\u7684\u306a\u30ed\u30c3\u30af\u306b\u300c\u5171\u6709\u30ed\u30c3\u30af\u300d\u3068\u300c\u6392\u4ed6\u30ed\u30c3\u30af\u300d\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<ul>\n<li><strong>\u5171\u6709\u30ed\u30c3\u30af (Shared Lock)<\/strong>\n<ul>\n<li>\u4e3b\u306b\u30c7\u30fc\u30bf\u306e<strong>\u8aad\u307f\u53d6\u308a\uff08<code>SELECT<\/code>\uff09<\/strong>\u6642\u306b\u7372\u5f97\u3057\u307e\u3059\u3002<\/li>\n<li>\u4ed6\u306e\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u3082\u5171\u6709\u30ed\u30c3\u30af\u3092\u7372\u5f97\u3057\u3066<strong>\u8aad\u307f\u53d6\u308b\u3053\u3068\u306f\u53ef\u80fd<\/strong>\u3067\u3059\u3002<\/li>\n<li>\u305f\u3060\u3057\u3001\u4ed6\u306e\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u304c\u6392\u4ed6\u30ed\u30c3\u30af\u3092\u7372\u5f97\u3057\u3066<strong>\u66f4\u65b0\u3059\u308b\u3053\u3068\u306f\u3067\u304d\u307e\u305b\u3093<\/strong>\u3002<\/li>\n<li><strong>\u4f8b\u3048\u308b\u306a\u3089<\/strong>: \u56f3\u66f8\u9928\u3067\u4ed6\u306e\u4eba\u3082\u95b2\u89a7\u3067\u304d\u308b\u3088\u3046\u306b\u300c\u9928\u5185\u95b2\u89a7\u4e2d\u300d\u306e\u672d\u3092\u7acb\u3066\u3066\u672c\u3092\u8aad\u3093\u3067\u3044\u308b\u72b6\u614b\u3002<\/li>\n<\/ul>\n<\/li>\n<li><strong>\u6392\u4ed6\u30ed\u30c3\u30af (Exclusive Lock)<\/strong>\n<ul>\n<li>\u4e3b\u306b\u30c7\u30fc\u30bf\u306e<strong>\u66f4\u65b0\uff08<code>INSERT<\/code>, <code>UPDATE<\/code>, <code>DELETE<\/code>\uff09<\/strong>\u6642\u306b\u7372\u5f97\u3057\u307e\u3059\u3002<\/li>\n<li>\u4ed6\u306e\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u306f\u3001\u5171\u6709\u30ed\u30c3\u30af\u3082\u6392\u4ed6\u30ed\u30c3\u30af\u3082\u7372\u5f97\u3067\u304d\u305a\u3001<strong>\u8aad\u307f\u53d6\u308a\u3082\u66f4\u65b0\u3082\u3067\u304d\u307e\u305b\u3093<\/strong>\u3002<\/li>\n<li><strong>\u4f8b\u3048\u308b\u306a\u3089<\/strong>: \u305d\u306e\u672c\u3092\u81ea\u5206\u3067\u4fee\u6b63\u3059\u308b\u305f\u3081\u306b\u300c\u7de8\u96c6\u4e2d\u300d\u306e\u672d\u3092\u7acb\u3066\u3066\u8cb8\u3057\u5207\u308a\u306b\u3057\u3066\u3044\u308b\u72b6\u614b\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>\u3053\u306e2\u3064\u306e\u30ed\u30c3\u30af\u306e\u95a2\u4fc2\u6027\u306f\u3001\u4ee5\u4e0b\u306e\u300c\u4e21\u7acb\u6027\u30de\u30c8\u30ea\u30af\u30b9\u300d\u3067\u6574\u7406\u3067\u304d\u307e\u3059\u3002<\/p>\n<table>\n<thead>\n<tr>\n<th>\u8981\u6c42\u3059\u308b\u30ed\u30c3\u30af<\/th>\n<th>\u65e2\u5b58\u306e\u30ed\u30c3\u30af\uff08\u5171\u6709\uff09<\/th>\n<th>\u65e2\u5b58\u306e\u30ed\u30c3\u30af\uff08\u6392\u4ed6\uff09<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>\u5171\u6709\u30ed\u30c3\u30af<\/strong><\/td>\n<td>\u25cb\uff08\u4e21\u7acb\u3059\u308b\uff09<\/td>\n<td>\u00d7\uff08\u7af6\u5408\u3059\u308b\uff09<\/td>\n<\/tr>\n<tr>\n<td><strong>\u6392\u4ed6\u30ed\u30c3\u30af<\/strong><\/td>\n<td>\u00d7\uff08\u7af6\u5408\u3059\u308b\uff09<\/td>\n<td>\u00d7\uff08\u7af6\u5408\u3059\u308b\uff09<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>\u6700\u60aa\u306e\u4e8b\u614b\u300c\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u300d\u3068\u305d\u306e\u56de\u907f\u7b56<\/h3>\n<p>\u30ed\u30c3\u30af\u306f\u30c7\u30fc\u30bf\u6574\u5408\u6027\u3092\u4fdd\u3064\u305f\u3081\u306b\u4e0d\u53ef\u6b20\u3067\u3059\u304c\u3001\u8907\u6570\u306e\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u304c\u4e92\u3044\u306b\u76f8\u624b\u306e\u30ed\u30c3\u30af\u89e3\u9664\u3092\u5f85\u3061\u3001\u6c38\u4e45\u306b\u51e6\u7406\u304c\u9032\u307e\u306a\u304f\u306a\u308b\u300c\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u300d\u3068\u3044\u3046\u6700\u60aa\u306e\u4e8b\u614b\u3092\u5f15\u304d\u8d77\u3053\u3059\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<div class=\"mermaid-diagram\">\n<p><strong>[\u56f3\u89e3: \u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u306e\u767a\u751f\u30e1\u30ab\u30cb\u30ba\u30e0]<\/strong><\/p>\n<pre><code>sequenceDiagram\n participant TX-A as \u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3A\n participant TX-B as \u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3B\n participant R-X as \u30ea\u30bd\u30fc\u30b9X\n participant R-Y as \u30ea\u30bd\u30fc\u30b9Y\n\n TX-A ->> R-X: lock(X)\n Note right of TX-A: \u6210\u529f\n TX-B ->> R-Y: lock(Y)\n Note right of TX-B: \u6210\u529f\n\n TX-A ->> R-Y: lock(Y)\n Note right of TX-A: B\u304cY\u3092\u30ed\u30c3\u30af\u4e2d\u306e\u305f\u3081\u5f85\u6a5f\n\n TX-B ->> R-X: lock(X)\n Note right of TX-B: A\u304cX\u3092\u30ed\u30c3\u30af\u4e2d\u306e\u305f\u3081\u5f85\u6a5f\n\n Note over TX-A, TX-B: \u4e92\u3044\u306b\u76f8\u624b\u306e\u30ed\u30c3\u30af\u89e3\u9664\u3092\u5f85\u3061\u3001\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u767a\u751f\uff01<\/code><\/pre>\n<\/div>\n<p><strong>\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u3092\u56de\u907f\u3059\u308b\u305f\u3081\u306e\u4e3b\u306a\u6226\u7565<\/strong><\/p>\n<ol>\n<li><strong>\u30ea\u30bd\u30fc\u30b9\u306e\u30ed\u30c3\u30af\u9806\u5e8f\u3092\u7d71\u4e00\u3059\u308b<\/strong>:<br \/>\n \u8907\u6570\u306e\u30c6\u30fc\u30d6\u30eb\u3092\u66f4\u65b0\u3059\u308b\u5834\u5408\u3001\u5fc5\u305a\u540c\u3058\u9806\u5e8f\uff08\u4f8b: \u5fc5\u305a<code>\u30c6\u30fc\u30d6\u30ebA<\/code> \u2192 <code>\u30c6\u30fc\u30d6\u30ebB<\/code>\uff09\u3067\u30ed\u30c3\u30af\u3092\u53d6\u5f97\u3059\u308b\u30eb\u30fc\u30eb\u3092\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u5168\u4f53\u3067\u5fb9\u5e95\u3057\u307e\u3059\u3002<\/li>\n<li><strong>\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u3092\u77ed\u304f\u3001\u30b7\u30f3\u30d7\u30eb\u306b\u4fdd\u3064<\/strong>:<br \/>\n \u30ed\u30c3\u30af\u3092\u4fdd\u6301\u3059\u308b\u6642\u9593\u304c\u9577\u304f\u306a\u308b\u307b\u3069\u3001\u4ed6\u306e\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u3068\u306e\u7af6\u5408\u3084\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u306e\u30ea\u30b9\u30af\u304c\u9ad8\u307e\u308a\u307e\u3059\u3002\u4e0d\u8981\u306a\u51e6\u7406\u306f\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u306e\u5916\u306b\u51fa\u3057\u307e\u3057\u3087\u3046\u3002<\/li>\n<li><strong>\u660e\u793a\u7684\u306a\u30ed\u30c3\u30af\u3068\u5206\u96e2\u30ec\u30d9\u30eb\u306e\u7406\u89e3<\/strong>:<br \/>\n \u5728\u5eab\u5f15\u304d\u5f53\u3066\u51e6\u7406\u306e\u3088\u3046\u306b\u7af6\u5408\u304c\u60f3\u5b9a\u3055\u308c\u308b\u5834\u9762\u3067\u306f\u3001<code>SELECT ... FOR UPDATE<\/code> \u3092\u7528\u3044\u3066\u4e8b\u524d\u306b\u884c\u3092\u30ed\u30c3\u30af\u3057\u3001\u66f4\u65b0\u306e\u885d\u7a81\u3092\u9632\u3050\u624b\u6cd5\u304c\u6709\u52b9\u3067\u3059\u3002\u307e\u305f\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u304c\u63d0\u4f9b\u3059\u308b\u300c\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u5206\u96e2\u30ec\u30d9\u30eb\u300d\u3092\u9069\u5207\u306b\u8a2d\u5b9a\u3059\u308b\u3053\u3068\u3082\u3001\u7af6\u5408\u3092\u30b3\u30f3\u30c8\u30ed\u30fc\u30eb\u3059\u308b\u4e0a\u3067\u91cd\u8981\u3067\u3059\u3002<\/li>\n<\/ol>\n<p><\/body><br \/>\n<\/html><\/p>\n<h2>\u30c7\u30fc\u30bf\u306e\u77db\u76fe\u3092\u9632\u3050\u756a\u4eba\uff01\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306e\u5236\u7d04\u3068\u6b63\u898f\u5316\u306e\u57fa\u790e<\/h2>\n<p>\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u304c\u6b63\u3057\u304f\u6a5f\u80fd\u3059\u308b\u305f\u3081\u306e\u5927\u524d\u63d0\u306f\u3001\u305d\u306e\u571f\u53f0\u3068\u306a\u308b\u30c7\u30fc\u30bf\u304c\u300c\u6b63\u3057\u304f\u3001\u77db\u76fe\u304c\u306a\u3044\u72b6\u614b\u300d\u3067\u3042\u308b\u3053\u3068\u3067\u3059\u3002\u4f8b\u3048\u3070\u3001\u5b58\u5728\u3057\u306a\u3044\u306f\u305a\u306e\u5546\u54c1ID\u3092\u6301\u3064\u6ce8\u6587\u30ec\u30b3\u30fc\u30c9\u3084\u3001\u5fc5\u9808\u3067\u3042\u308b\u306f\u305a\u306e\u30e6\u30fc\u30b6\u30fc\u540d\u304c\u7a7a\u306e\u9867\u5ba2\u30c7\u30fc\u30bf\u304c\u5b58\u5728\u3059\u308c\u3070\u3001\u30b7\u30b9\u30c6\u30e0\u306f\u6df1\u523b\u306a\u4e0d\u5177\u5408\u3092\u5f15\u304d\u8d77\u3053\u3057\u307e\u3059\u3002\u3053\u306e\u3088\u3046\u306a\u4e8b\u614b\u3092\u9632\u304e\u3001\u30c7\u30fc\u30bf\u306e\u54c1\u8cea\u3092\u4fdd\u8a3c\u3059\u308b\u4ed5\u7d44\u307f\u304c\u300c\u30c7\u30fc\u30bf\u6574\u5408\u6027\u300d\u306e\u78ba\u4fdd\u3067\u3059\u3002<\/p>\n<h3>\u30c7\u30fc\u30bf\u306e\u9580\u756a\u300c\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u5236\u7d04\u300d<\/h3>\n<p>\u30c7\u30fc\u30bf\u6574\u5408\u6027\u3092\u5b88\u308b\u305f\u3081\u306e\u6700\u3082\u76f4\u63a5\u7684\u3067\u5f37\u529b\u306a\u6a5f\u80fd\u304c\u300c\u5236\u7d04\uff08Constraint\uff09\u300d\u3067\u3059\u3002\u5236\u7d04\u306f\u3001\u30c6\u30fc\u30d6\u30eb\u5b9a\u7fa9\u306e\u969b\u306b\u8a2d\u5b9a\u3059\u308b\u300c\u30eb\u30fc\u30eb\u300d\u3067\u3042\u308a\u3001\u3053\u306e\u30eb\u30fc\u30eb\u306b\u9055\u53cd\u3059\u308b\u30c7\u30fc\u30bf\u306e<code>INSERT<\/code>\u3084<code>UPDATE<\/code>\u3092\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u81ea\u8eab\u304c\u30d6\u30ed\u30c3\u30af\u3057\u3066\u304f\u308c\u307e\u3059\u3002\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u5074\u306e\u5b9f\u88c5\u30df\u30b9\u306b\u3088\u308b\u4e0d\u6b63\u306a\u30c7\u30fc\u30bf\u6df7\u5165\u3092\u9632\u3050\u305f\u3081\u306e\u6700\u5f8c\u306e\u7826\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n<table>\n<thead>\n<tr>\n<th>\u4e3b\u8981\u306a\u5236\u7d04<\/th>\n<th>\u5f79\u5272\u3068\u5177\u4f53\u4f8b<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>\u4e3b\u30ad\u30fc (PRIMARY KEY)<\/strong><\/td>\n<td>\u5404\u884c\u3092\u4e00\u610f\u306b\u8b58\u5225\u3059\u308b\u305f\u3081\u306e\u5236\u7d04\u3002<code>NULL<\/code>\u306f\u8a31\u53ef\u3055\u308c\u305a\u3001\u91cd\u8907\u3082\u8a31\u3055\u308c\u307e\u305b\u3093\u3002<br \/>\u4f8b\uff1a\u5f93\u696d\u54e1\u30c6\u30fc\u30d6\u30eb\u306e\u300c\u5f93\u696d\u54e1ID\u300d<\/td>\n<\/tr>\n<tr>\n<td><strong>\u5916\u90e8\u30ad\u30fc (FOREIGN KEY)<\/strong><\/td>\n<td>\u4ed6\u306e\u30c6\u30fc\u30d6\u30eb\u306e\u4e3b\u30ad\u30fc\u3092\u53c2\u7167\u3059\u308b\u5236\u7d04\u3002\u95a2\u9023\u5148\u306e\u30c6\u30fc\u30d6\u30eb\u306b\u5b58\u5728\u3057\u306a\u3044\u5024\u306e\u767b\u9332\u3092\u9632\u304e\u307e\u3059\u3002<br \/>\u4f8b\uff1a\u6ce8\u6587\u30c6\u30fc\u30d6\u30eb\u306e\u300c\u9867\u5ba2ID\u300d\u306f\u3001\u5fc5\u305a\u9867\u5ba2\u30c6\u30fc\u30d6\u30eb\u306b\u5b58\u5728\u3059\u308bID\u3067\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\u3002<\/td>\n<\/tr>\n<tr>\n<td><strong>\u4e00\u610f\u6027 (UNIQUE)<\/strong><\/td>\n<td>\u6307\u5b9a\u3057\u305f\u5217\u306e\u5024\u304c\u30c6\u30fc\u30d6\u30eb\u5185\u3067\u91cd\u8907\u3057\u306a\u3044\u3053\u3068\u3092\u4fdd\u8a3c\u3057\u307e\u3059\u3002<br \/>\u4f8b\uff1a\u30e6\u30fc\u30b6\u30fc\u30c6\u30fc\u30d6\u30eb\u306e\u300c\u30e1\u30fc\u30eb\u30a2\u30c9\u30ec\u30b9\u300d<\/td>\n<\/tr>\n<tr>\n<td><strong>\u975eNULL (NOT NULL)<\/strong><\/td>\n<td>\u6307\u5b9a\u3057\u305f\u5217\u306b<code>NULL<\/code>\u5024\u304c\u5165\u308b\u3053\u3068\u3092\u7981\u6b62\u3057\u307e\u3059\u3002<br \/>\u4f8b\uff1a\u4f1a\u54e1\u767b\u9332\u30d5\u30a9\u30fc\u30e0\u3067\u300c\u6c0f\u540d\u300d\u306e\u5165\u529b\u306f\u5fc5\u9808\u3002<\/td>\n<\/tr>\n<tr>\n<td><strong>\u691c\u67fb (CHECK)<\/strong><\/td>\n<td>\u6307\u5b9a\u3057\u305f\u5217\u306e\u5024\u304c\u3001\u7279\u5b9a\u306e\u6761\u4ef6\u3092\u6e80\u305f\u3059\u3053\u3068\u3092\u4fdd\u8a3c\u3057\u307e\u3059\u3002<br \/>\u4f8b\uff1a\u5546\u54c1\u30c6\u30fc\u30d6\u30eb\u306e\u300c\u4fa1\u683c\u300d\u306f\u5fc5\u305a0\u4ee5\u4e0a\u3067\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>\u3010\u30b3\u30fc\u30c9\u4f8b: \u5236\u7d04\u3092\u5229\u7528\u3057\u305f\u30c6\u30fc\u30d6\u30eb\u4f5c\u6210\u3011<\/strong><\/p>\n<pre><code>CREATE TABLE employees (\n employee_id INTEGER PRIMARY KEY,\n email VARCHAR(255) NOT NULL UNIQUE,\n name VARCHAR(100) NOT NULL,\n department_id INTEGER REFERENCES departments(department_id), -- \u5916\u90e8\u30ad\u30fc\n salary INTEGER CHECK (salary >= 0)\n);<\/code><\/pre>\n<h3>\u8a2d\u8a08\u306e\u571f\u53f0\u300c\u6b63\u898f\u5316\u300d<\/h3>\n<p>\u6b63\u898f\u5316\u3068\u306f\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u8a2d\u8a08\u6642\u306b\u30c7\u30fc\u30bf\u306e\u91cd\u8907\u3092\u306a\u304f\u3057\u3001\u6574\u5408\u6027\u3092\u4fdd\u3061\u3084\u3059\u3044\u3088\u3046\u306b\u30c6\u30fc\u30d6\u30eb\u3092\u5206\u5272\u30fb\u6574\u7406\u3057\u3066\u3044\u304f\u30d7\u30ed\u30bb\u30b9\u3067\u3059\u3002\u6b63\u898f\u5316\u3092\u884c\u3046\u3053\u3068\u3067\u3001\u300c\u66f4\u65b0\u6f0f\u308c\u300d\u306e\u3088\u3046\u306a\u4eba\u70ba\u7684\u30df\u30b9\uff08\u66f4\u65b0\u7570\u5e38\uff09\u3092\u9632\u304e\u3001\u30c7\u30fc\u30bf\u3092\u52b9\u7387\u7684\u306b\u7ba1\u7406\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p><strong>\u4f8b\u3048\u308b\u306a\u3089\u3001\u300c\u4f4f\u6240\u9332\u300d\u306e\u6574\u7406\u3067\u3059\u3002<\/strong> \u8907\u6570\u306e\u30ea\u30b9\u30c8\u306b\u53cb\u4eba\u306e\u53e4\u3044\u4f4f\u6240\u3068\u65b0\u3057\u3044\u4f4f\u6240\u304c\u6df7\u5728\u3057\u3066\u3044\u308b\u3068\u3001\u3069\u3061\u3089\u304c\u6b63\u3057\u3044\u304b\u5206\u304b\u3089\u306a\u304f\u306a\u308a\u307e\u3059\u3002\u3053\u308c\u3092\u300c\u4f4f\u6240\u9332\u300d\u3068\u3044\u3046\u30de\u30b9\u30bf\u30fc\u30c7\u30fc\u30bf\u3092\u4e00\u3064\u3060\u3051\u4f5c\u308a\u3001\u4ed6\u306e\u30ea\u30b9\u30c8\u304b\u3089\u306f\u305d\u306e\u30de\u30b9\u30bf\u30fc\u3092\u53c2\u7167\u3059\u308b\u5f62\u306b\u3059\u308c\u3070\u3001\u4f4f\u6240\u5909\u66f4\u306f\u30de\u30b9\u30bf\u30fc\u306e1\u30f6\u6240\u3092\u4fee\u6b63\u3059\u308b\u3060\u3051\u3067\u6e08\u307f\u307e\u3059\u3002<\/p>\n<div class=\"mermaid-diagram\">\n<p><strong>[\u56f3\u89e3: \u975e\u6b63\u898f\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u6b63\u898f\u5316\u3055\u308c\u305f\u30c6\u30fc\u30d6\u30eb\u3078\u306e\u5206\u5272]<\/strong><\/p>\n<pre><code>graph TD\n subgraph Before (\u975e\u6b63\u898f)\n T1[\"\u6ce8\u6587\u30c6\u30fc\u30d6\u30eb\\n(\u6ce8\u6587ID, \u6ce8\u6587\u65e5, \u9867\u5ba2ID, <b>\u9867\u5ba2\u540d<\/b>, <b>\u9867\u5ba2\u4f4f\u6240<\/b>, \u5546\u54c1ID, <b>\u5546\u54c1\u540d<\/b>, <b>\u5358\u4fa1<\/b>, \u6570\u91cf)\"]\n end\n\n subgraph After (\u6b63\u898f\u5316)\n T2[\u9867\u5ba2\u30c6\u30fc\u30d6\u30eb\\n(<u>\u9867\u5ba2ID<\/u>, \u9867\u5ba2\u540d, \u9867\u5ba2\u4f4f\u6240)]\n T3[\u5546\u54c1\u30c6\u30fc\u30d6\u30eb\\n(<u>\u5546\u54c1ID<\/u>, \u5546\u54c1\u540d, \u5358\u4fa1)]\n T4[\u6ce8\u6587\u30c6\u30fc\u30d6\u30eb\\n(<u>\u6ce8\u6587ID<\/u>, \u6ce8\u6587\u65e5, \u9867\u5ba2ID(FK), \u5546\u54c1ID(FK), \u6570\u91cf)]\n end\n\n T1 -- \u5206\u5272 --> T2;\n T1 -- \u5206\u5272 --> T3;\n T1 -- \u5206\u5272 --> T4;\n\n T4 -- \u53c2\u7167 --> T2;\n T4 -- \u53c2\u7167 --> T3;<\/code><\/pre>\n<\/div>\n<p>\u5b9f\u52d9\u3067\u306f\u591a\u304f\u306e\u5834\u5408\u3001<strong>\u7b2c3\u6b63\u898f\u5f62\uff083NF\uff09<\/strong> \u3092\u76ee\u6a19\u306b\u8a2d\u8a08\u3059\u308b\u3053\u3068\u3067\u3001\u30c7\u30fc\u30bf\u306e\u5197\u9577\u6027\u3068\u7ba1\u7406\u306e\u8907\u96d1\u6027\u306e\u30d0\u30e9\u30f3\u30b9\u3092\u3068\u308a\u307e\u3059\u3002\u6b63\u898f\u5316\u306f\u3001\u5805\u7262\u306a\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3092\u69cb\u7bc9\u3059\u308b\u305f\u3081\u306e\u8a2d\u8a08\u601d\u60f3\u305d\u306e\u3082\u306e\u306a\u306e\u3067\u3059\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>SQL\u5fdc\u7528Tips\u30c9\u30e9\u30d5\u30c8 SQL\u306e\u57fa\u672c\u7684\u306a\u66f8\u304d\u65b9\u3092\u30de\u30b9\u30bf\u30fc\u3057\u305f\u30a8\u30f3\u30b8\u30cb\u30a2\u304c\u3001\u6b21\u306a\u308b\u30b9\u30c6\u30c3\u30d7\u3068\u3057\u3066\u5411\u304d\u5408\u3046\u306e\u304c\u300c\u5b9f\u52d9\u3067\u901a\u7528\u3059\u308bSQL\u300d\u306e\u58c1\u3067\u3059\u3002\u30c6\u30b9\u30c8\u74b0\u5883\u3067\u306f\u554f\u984c\u306a\u304f\u52d5\u3044\u305f\u30af\u30a8\u30ea\u304c\u3001\u672c\u756a\u74b0\u5883\u306e\u5927\u91cf\u30c7\u30fc … <\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","columnck":"","stmeta_robots":"index, 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{"id":6075,"date":"2025-09-28T00:54:41","date_gmt":"2025-09-27T15:54:41","guid":{"rendered":"https:\/\/sky-peace.net\/?p=6075"},"modified":"2025-09-28T00:54:41","modified_gmt":"2025-09-27T15:54:41","slug":"sql-deadlock","status":"publish","type":"post","link":"https:\/\/sky-peace.net\/certified\/sql-deadlock\/","title":{"rendered":"SQL\u304c\u300c\u9045\u3044\u30fb\u6b62\u307e\u308b\u30fb\u58ca\u308c\u308b\u300d\u3092\u9632\u3050\uff01\u5b9f\u884c\u8a08\u753b\u30fb\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u30fb\u6b63\u898f\u5316\u304b\u3089\u5b66\u3076DB\u8a2d\u8a08\u306e\u52d8\u6240"},"content":{"rendered":"

\n
\n
\n
\n
\n SQL\u5fdc\u7528Tips\u30c9\u30e9\u30d5\u30c8<\/title><\/p>\n<style>\n body { font-family: Meiryo, 'Hiragino Kaku Gothic ProN', 'MS PGothic', sans-serif; line-height: 1.8; color: #333; }\n h2 { font-size: 1.5em; color: #1a0dab; border-bottom: 2px solid #1a0dab; padding-bottom: 0.5em; margin-top: 2em; margin-bottom: 1em; }\n h3 { font-size: 1.2em; color: #333; border-left: 5px solid #1a0dab; padding-left: 0.8em; margin-top: 1.5em; margin-bottom: 1em; }\n p, li { font-size: 1em; }\n table { border-collapse: collapse; width: 100%; margin: 1.5em 0; border: 1px solid #ccc; }\n th, td { border: 1px solid #ccc; padding: 0.8em; text-align: left; }\n th { background-color: #f2f2f2; font-weight: bold; }\n pre { background-color: #f5f5f5; padding: 1em; border: 1px solid #ccc; border-radius: 4px; white-space: pre-wrap; word-wrap: break-word; }\n code { font-family: 'Courier New', Courier, monospace; }\n .mermaid-diagram { text-align: center; padding: 1em; border: 1px dashed #aaa; margin: 1.5em 0; background-color: #fafafa; }\n .mermaid-diagram pre { background-color: #fff; text-align: left; }\n <\/style>\n<p><\/head><br \/>\n<body><\/p>\n<p>SQL\u306e\u57fa\u672c\u7684\u306a\u66f8\u304d\u65b9\u3092\u30de\u30b9\u30bf\u30fc\u3057\u305f\u30a8\u30f3\u30b8\u30cb\u30a2\u304c\u3001\u6b21\u306a\u308b\u30b9\u30c6\u30c3\u30d7\u3068\u3057\u3066\u5411\u304d\u5408\u3046\u306e\u304c\u300c\u5b9f\u52d9\u3067\u901a\u7528\u3059\u308bSQL\u300d\u306e\u58c1\u3067\u3059\u3002\u30c6\u30b9\u30c8\u74b0\u5883\u3067\u306f\u554f\u984c\u306a\u304f\u52d5\u3044\u305f\u30af\u30a8\u30ea\u304c\u3001\u672c\u756a\u74b0\u5883\u306e\u5927\u91cf\u30c7\u30fc\u30bf\u3084\u540c\u6642\u30a2\u30af\u30bb\u30b9\u306b\u3088\u3063\u3066\u6df1\u523b\u306a\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u4f4e\u4e0b\u3092\u5f15\u304d\u8d77\u3053\u3057\u305f\u308a\u3001\u610f\u56f3\u3057\u306a\u3044\u30c7\u30fc\u30bf\u4e0d\u6574\u5408\u3092\u62db\u3044\u305f\u308a\u3059\u308b\u30b1\u30fc\u30b9\u306f\u5c11\u306a\u304f\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n<p>\u3053\u306e\u554f\u984c\u306e\u6839\u5e95\u306b\u3042\u308b\u306e\u304c\u3001\u300c\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u300d\u300c\u30ed\u30c3\u30af\u7af6\u5408\u300d\u300c\u30c7\u30fc\u30bf\u6574\u5408\u6027\u300d\u3068\u3044\u30463\u3064\u306e\u91cd\u8981\u306a\u8996\u70b9\u3067\u3059\u3002\u3053\u308c\u3089\u306f\u5358\u306a\u308b\u77e5\u8b58\u3067\u306f\u306a\u304f\u3001\u5b89\u5b9a\u3057\u305f\u30b7\u30b9\u30c6\u30e0\u3092\u652f\u3048\u308b\u305f\u3081\u306e\u5b9f\u8df5\u7684\u306a\u6280\u8853\u3068\u8a00\u3048\u307e\u3059\u3002\u7279\u306b\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u30b9\u30da\u30b9\u30da\u30b7\u30e3\u30ea\u30b9\u30c8\u8a66\u9a13\u3084\u5fdc\u7528\u60c5\u5831\u6280\u8853\u8005\u8a66\u9a13\u306e\u5348\u5f8c\u554f\u984c\u3067\u306f\u3001\u3053\u308c\u3089\u306e\u5fdc\u7528\u529b\u3092\u554f\u3046\u8a2d\u554f\u304c\u983b\u51fa\u3057\u307e\u3059\u3002<\/p>\n<p>\u672c\u8a18\u4e8b\u3067\u306f\u3001SQL\u306e\u5fdc\u7528\u529b\u3092\u9ad8\u3081\u305f\u3044\u30a8\u30f3\u30b8\u30cb\u30a2\u306b\u5411\u3051\u3066\u3001\u5b9f\u52d9\u3067\u983b\u7e41\u306b\u76f4\u9762\u3059\u308b\u4e0a\u8a183\u3064\u306e\u30c6\u30fc\u30de\u306b\u7126\u70b9\u3092\u5f53\u3066\u3066\u89e3\u8aac\u3057\u307e\u3059\u3002\u5b9f\u884c\u8a08\u753b\u306e\u8aad\u307f\u89e3\u304d\u65b9\u304b\u3089\u3001\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u3092\u56de\u907f\u3059\u308b\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u8a2d\u8a08\u3001\u30c7\u30fc\u30bf\u306e\u77db\u76fe\u3092\u9632\u3050\u5236\u7d04\u306e\u6d3b\u7528\u307e\u3067\u3001\u5177\u4f53\u7684\u306a\u30b3\u30fc\u30c9\u4f8b\u3084\u56f3\u89e3\u3092\u4ea4\u3048\u306a\u304c\u3089\u3001\u7406\u8ad6\u3068\u5b9f\u8df5\u3092\u3064\u306a\u3050\u77e5\u8b58\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002\u3053\u306e\u8a18\u4e8b\u3092\u8aad\u307f\u7d42\u3048\u308b\u9803\u306b\u306f\u3001\u3042\u306a\u305f\u306eSQL\u306f\u4e00\u6bb5\u3068\u6d17\u7df4\u3055\u308c\u3001\u5805\u7262\u306a\u3082\u306e\u306b\u306a\u3063\u3066\u3044\u308b\u306f\u305a\u3067\u3059\u3002<\/p>\n<h2>SQL\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0\u306e\u7b2c\u4e00\u6b69\u2502\u5b9f\u884c\u8a08\u753b\u306e\u89e3\u8aad\u3068\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u6226\u7565<\/h2>\n<p>\u3069\u3093\u306a\u306b\u512a\u308c\u305f\u6a5f\u80fd\u3092\u6301\u3064\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u3067\u3082\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3078\u306e\u554f\u3044\u5408\u308f\u305b\uff08\u30af\u30a8\u30ea\uff09\u304c\u9045\u3051\u308c\u3070\u3001\u30e6\u30fc\u30b6\u30fc\u4f53\u9a13\u306f\u8457\u3057\u304f\u640d\u306a\u308f\u308c\u307e\u3059\u3002SQL\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0\u306f\u3001\u5fdc\u7b54\u6027\u306e\u9ad8\u3044\u30b7\u30b9\u30c6\u30e0\u3092\u7dad\u6301\u3059\u308b\u305f\u3081\u306e\u5fc5\u9808\u30b9\u30ad\u30eb\u3067\u3059\u3002\u3053\u3053\u3067\u306f\u3001\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u4f4e\u4e0b\u306e\u5178\u578b\u7684\u306a\u539f\u56e0\u3092\u7a81\u304d\u6b62\u3081\u3001\u305d\u306e\u5bfe\u7b56\u306e\u57fa\u672c\u3068\u306a\u308b\u300c\u5b9f\u884c\u8a08\u753b\u300d\u3068\u300c\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u300d\u306b\u3064\u3044\u3066\u89e3\u8aac\u3057\u307e\u3059\u3002<\/p>\n<h3>\u306a\u305cSQL\u306f\u9045\u304f\u306a\u308b\u306e\u304b\uff1f \u5178\u578b\u7684\u306a\u539f\u56e0<\/h3>\n<p>SQL\u304c\u9045\u304f\u306a\u308b\u539f\u56e0\u306f\u69d8\u3005\u3067\u3059\u304c\u3001\u7279\u306b\u983b\u51fa\u3059\u308b\u30d1\u30bf\u30fc\u30f3\u306f\u4ee5\u4e0b\u306e\u901a\u308a\u3067\u3059\u3002\u3053\u308c\u3089\u306f\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u30b9\u30da\u30b7\u30e3\u30ea\u30b9\u30c8\u8a66\u9a13\u306e\u5348\u5f8c\u554f\u984c\u3067\u3082\u983b\u7e41\u306b\u554f\u308f\u308c\u308b\u8ad6\u70b9\u3067\u3059\u3002<\/p>\n<table>\n<thead>\n<tr>\n<th>\u539f\u56e0<\/th>\n<th>\u89e3\u8aac<\/th>\n<th>\u5b9f\u52d9\u3067\u306e\u4f8b\u3048<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>\u30d5\u30eb\u30c6\u30fc\u30d6\u30eb\u30b9\u30ad\u30e3\u30f3<\/strong><\/td>\n<td>\u76ee\u7684\u306e\u30c7\u30fc\u30bf\u3092\u63a2\u3059\u305f\u3081\u306b\u3001\u30c6\u30fc\u30d6\u30eb\u306e\u5168\u30ec\u30b3\u30fc\u30c9\u3092\u6700\u521d\u304b\u3089\u6700\u5f8c\u307e\u3067\u30b9\u30ad\u30e3\u30f3\u3057\u3066\u3057\u307e\u3046\u3053\u3068\u3002\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u304c\u9069\u5207\u306b\u5229\u7528\u3055\u308c\u3066\u3044\u306a\u3044\u5834\u5408\u306b\u767a\u751f\u3057\u307e\u3059\u3002<\/td>\n<td>\u767e\u79d1\u4e8b\u5178\u3067\u8abf\u3079\u7269\u3092\u3059\u308b\u306e\u306b\u3001\u76ee\u6b21\u3084\u7d22\u5f15\u3092\u4f7f\u308f\u305a1\u30da\u30fc\u30b8\u76ee\u304b\u3089\u9806\u306b\u63a2\u3059\u3088\u3046\u306a\u72b6\u614b\u3002<\/td>\n<\/tr>\n<tr>\n<td><strong>\u4e0d\u9069\u5207\u306aJOIN<\/strong><\/td>\n<td>\u5de8\u5927\u306a\u30c6\u30fc\u30d6\u30eb\u540c\u58eb\u3092\u975e\u52b9\u7387\u306a\u6761\u4ef6\u3067\u7d50\u5408\u3057\u305f\u308a\u3001\u5fc5\u8981\u4ee5\u4e0a\u306b\u591a\u304f\u306e\u30c6\u30fc\u30d6\u30eb\u3092\u7d50\u5408\u3057\u305f\u308a\u3059\u308b\u3053\u3068\u3067\u3001\u51e6\u7406\u30b3\u30b9\u30c8\u304c\u7206\u767a\u7684\u306b\u5897\u52a0\u3057\u307e\u3059\u3002<\/td>\n<td>\u8907\u6570\u306e\u540d\u7c3f\u3092\u7a81\u5408\u3059\u308b\u969b\u3001\u5171\u901a\u306eID\u3092\u4f7f\u308f\u305a\u306b\u5168\u54e1\u306e\u30d7\u30ed\u30d5\u30a3\u30fc\u30eb\u3092\u4e00\u3064\u3072\u3068\u3064\u898b\u6bd4\u3079\u3066\u3044\u308b\u3088\u3046\u306a\u72b6\u614b\u3002<\/td>\n<\/tr>\n<tr>\n<td><strong>WHERE\u53e5\u306e\u975e\u52b9\u7387\u306a\u6761\u4ef6<\/strong><\/td>\n<td><code>WHERE a + 1 = 10<\/code> \u306e\u3088\u3046\u306b\u3001\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u304c\u8a2d\u5b9a\u3055\u308c\u305f\u5217\uff08\u3053\u3053\u3067\u306f <code>a<\/code>\uff09\u306b\u76f4\u63a5\u8a08\u7b97\u3084\u95a2\u6570\u3092\u9069\u7528\u3059\u308b\u3068\u3001\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u304c\u5229\u7528\u3067\u304d\u306a\u304f\u306a\u308a\u307e\u3059\u3002<\/td>\n<td>\u7d22\u5f15\u306b\u300c\u7530\u4e2d\u300d\u3067\u8f09\u3063\u3066\u3044\u308b\u4eba\u3092\u63a2\u3059\u306e\u306b\u3001\u308f\u3056\u308f\u3056\u5168\u54e1\u306b\u300c\u82d7\u5b57\u306f\u4f55\u3067\u3059\u304b\uff1f\u300d\u3068\u805e\u3044\u3066\u56de\u308b\u3088\u3046\u306a\u3082\u306e\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>\u30dc\u30c8\u30eb\u30cd\u30c3\u30af\u3092\u898b\u3064\u3051\u308b\u7f85\u91dd\u76e4\u300c\u5b9f\u884c\u8a08\u753b\u300d<\/h3>\n<p>\u300c\u5b9f\u884c\u8a08\u753b\u300d\u3068\u306f\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u304cSQL\u3092\u53d7\u3051\u53d6\u3063\u305f\u969b\u306b\u3001\u300c\u3069\u306e\u3088\u3046\u306a\u624b\u9806\u3067\u30c7\u30fc\u30bf\u306b\u30a2\u30af\u30bb\u30b9\u3057\u3001\u7d50\u679c\u3092\u8fd4\u3059\u304b\u300d\u3068\u3044\u3046\u5185\u90e8\u7684\u306a\u51e6\u7406\u8a08\u753b\u306e\u3053\u3068\u3067\u3059\u3002SQL\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0\u306f\u3001\u307e\u305a\u3053\u306e\u5b9f\u884c\u8a08\u753b\u3092\u8aad\u307f\u89e3\u304d\u3001\u3069\u3053\u306b\u7121\u99c4\u304c\u3042\u308b\u306e\u304b\uff08\u30dc\u30c8\u30eb\u30cd\u30c3\u30af\uff09\u3092\u7279\u5b9a\u3059\u308b\u3053\u3068\u304b\u3089\u59cb\u307e\u308a\u307e\u3059\u3002<\/p>\n<p>\u4f8b\u3048\u3070\u3001<code>EXPLAIN<\/code> \u3068\u3044\u3046\u30b3\u30de\u30f3\u30c9\u3092\u4f7f\u3046\u3053\u3068\u3067\u3001\u3053\u306e\u5b9f\u884c\u8a08\u753b\u3092\u78ba\u8a8d\u3067\u304d\u307e\u3059\u3002<\/p>\n<p><strong>\u3010\u30b3\u30fc\u30c9\u4f8b: \u30e6\u30fc\u30b6\u30fc\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u7279\u5b9a\u306eemail\u3092\u6301\u3064\u30e6\u30fc\u30b6\u30fc\u3092\u691c\u7d22\u3011<\/strong><\/p>\n<pre><code>EXPLAIN SELECT user_id, user_name\nFROM users\nWHERE email = 'test.user@example.com';<\/code><\/pre>\n<p>\u3053\u306e\u7d50\u679c\u3092\u898b\u3066\u3001\u300c<code>type: ALL<\/code>\uff08\u30d5\u30eb\u30c6\u30fc\u30d6\u30eb\u30b9\u30ad\u30e3\u30f3\uff09\u306b\u306a\u3063\u3066\u3044\u306a\u3044\u304b\u300d\u300c<code>key<\/code>\uff08\u4f7f\u7528\u3059\u308b\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\uff09\u304c\u610f\u56f3\u3057\u305f\u3082\u306e\u306b\u306a\u3063\u3066\u3044\u308b\u304b\u300d\u306a\u3069\u3092\u78ba\u8a8d\u3057\u3001\u554f\u984c\u70b9\u3092\u7279\u5b9a\u3057\u307e\u3059\u3002\u5b9f\u884c\u8a08\u753b\u306f\u3001\u307e\u308b\u3067\u30ab\u30fc\u30ca\u30d3\u304c\u6700\u9069\u306a\u30eb\u30fc\u30c8\u3092\u63d0\u793a\u3057\u3066\u304f\u308c\u308b\u3088\u3046\u306b\u3001SQL\u306e\u51e6\u7406\u7d4c\u8def\u3092\u53ef\u8996\u5316\u3057\u3066\u304f\u308c\u308b\u5f37\u529b\u306a\u30c4\u30fc\u30eb\u306a\u306e\u3067\u3059\u3002<\/p>\n<h3>\u57fa\u672c\u306b\u3057\u3066\u6700\u5f37\u306e\u6b66\u5668\u300c\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u300d<\/h3>\n<p>\u5b9f\u884c\u8a08\u753b\u3092\u5206\u6790\u3057\u3066\u30d5\u30eb\u30c6\u30fc\u30d6\u30eb\u30b9\u30ad\u30e3\u30f3\u306a\u3069\u306e\u554f\u984c\u304c\u898b\u3064\u304b\u3063\u305f\u5834\u5408\u3001\u6700\u3082\u57fa\u672c\u7684\u306a\u89e3\u6c7a\u7b56\u304c\u300c\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u300d\u306e\u4f5c\u6210\u3067\u3059\u3002\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306f\u3001\u7279\u5b9a\u306e\u5217\u306e\u5024\u3092\u30ad\u30fc\u3068\u3057\u3066\u3001\u5bfe\u5fdc\u3059\u308b\u30ec\u30b3\u30fc\u30c9\u306e\u4f4d\u7f6e\u60c5\u5831\u3092\u4fdd\u6301\u3059\u308b\u4ed5\u7d44\u307f\u3067\u3001\u672c\u306e\u5dfb\u672b\u306b\u3042\u308b\u300c\u7d22\u5f15\u300d\u306b\u4f8b\u3048\u3089\u308c\u307e\u3059\u3002<\/p>\n<div class=\"mermaid-diagram\">\n<p><strong>[\u56f3\u89e3: \u30d5\u30eb\u30c6\u30fc\u30d6\u30eb\u30b9\u30ad\u30e3\u30f3\u3068\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u30b9\u30ad\u30e3\u30f3\u306e\u6982\u5ff5\u6bd4\u8f03]<\/strong><\/p>\n<pre><code>graph TD\n subgraph \u30d5\u30eb\u30c6\u30fc\u30d6\u30eb\u30b9\u30ad\u30e3\u30f3\uff08\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306a\u3057\uff09\n A[\u691c\u7d22\u958b\u59cb] --> B{\u30c7\u30fc\u30bf\u30d6\u30ed\u30c3\u30af1};\n B --> C{\u30c7\u30fc\u30bf\u30d6\u30ed\u30c3\u30af2};\n C --> D{...};\n D --> E{\u30c7\u30fc\u30bf\u30d6\u30ed\u30c3\u30afN};\n E --> F[\u76ee\u7684\u306e\u30c7\u30fc\u30bf\u767a\u898b or \u898b\u3064\u304b\u3089\u306a\u3044];\n end\n\n subgraph \u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u30b9\u30ad\u30e3\u30f3\n G[\u691c\u7d22\u958b\u59cb] --> H{\u30a4\u30f3\u30c7\u30c3\u30af\u30b9};\n H -- \u76ee\u7684\u306e\u30c7\u30fc\u30bf\u306e\u4f4d\u7f6e\u60c5\u5831\u3092\u7279\u5b9a --> I{\u5bfe\u8c61\u30c7\u30fc\u30bf\u30d6\u30ed\u30c3\u30af};\n I --> J[\u76ee\u7684\u306e\u30c7\u30fc\u30bf\u767a\u898b];\n end<\/code><\/pre>\n<\/div>\n<p>\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306f <code>WHERE<\/code> \u53e5\u3067\u306e\u7d5e\u308a\u8fbc\u307f\u3084 <code>JOIN<\/code> \u306e\u7d50\u5408\u6761\u4ef6\u3001<code>ORDER BY<\/code> \u3067\u306e\u30bd\u30fc\u30c8\u51e6\u7406\u3092\u5287\u7684\u306b\u9ad8\u901f\u5316\u3057\u307e\u3059\u3002\u305f\u3060\u3057\u3001\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3092\u7121\u95c7\u306b\u8ffd\u52a0\u3059\u308b\u3068\u3001\u30c7\u30fc\u30bf\u306e\u767b\u9332\u30fb\u66f4\u65b0\u30fb\u524a\u9664\uff08<code>INSERT<\/code>, <code>UPDATE<\/code>, <code>DELETE<\/code>\uff09\u6642\u306b\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u66f4\u65b0\u30b3\u30b9\u30c8\u304c\u767a\u751f\u3057\u3001\u9006\u306b\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u4f4e\u4e0b\u3059\u308b\u3053\u3068\u3082\u3042\u308a\u307e\u3059\u3002\u3069\u306e\u5217\u306b\u3001\u3069\u306e\u3088\u3046\u306a\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3092\u4f5c\u6210\u3059\u308b\u304b\u306e\u8a2d\u8a08\u304c\u975e\u5e38\u306b\u91cd\u8981\u3067\u3059\u3002<\/p>\n<h2>\u540c\u6642\u5b9f\u884c\u5236\u5fa1\u306e\u6838\u5fc3\uff01\u30ed\u30c3\u30af\u7af6\u5408\u3068\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u3092\u56de\u907f\u3059\u308bSQL\u6226\u7565<\/h2>\n<p>\u8907\u6570\u306e\u30e6\u30fc\u30b6\u30fc\u304c\u540c\u6642\u306b\u30b7\u30b9\u30c6\u30e0\u3092\u5229\u7528\u3059\u308b\u74b0\u5883\u3067\u306f\u3001\u300c\u8ab0\u304b\u304c\u30c7\u30fc\u30bf\u3092\u66f4\u65b0\u3057\u3066\u3044\u308b\u6700\u4e2d\u306b\u3001\u5225\u306e\u8ab0\u304b\u304c\u305d\u306e\u30c7\u30fc\u30bf\u3092\u8aad\u307f\u66f8\u304d\u3057\u3088\u3046\u3068\u3059\u308b\u300d\u3068\u3044\u3046\u72b6\u6cc1\u304c\u5e38\u306b\u767a\u751f\u3057\u307e\u3059\u3002\u3053\u306e\u3088\u3046\u306a\u540c\u6642\u5b9f\u884c\u3092\u9069\u5207\u306b\u5236\u5fa1\u3057\u306a\u3044\u3068\u3001\u30c7\u30fc\u30bf\u304c\u77db\u76fe\u3057\u305f\u72b6\u614b\u306b\u9665\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u306e\u5236\u5fa1\u306e\u6838\u5fc3\u3068\u306a\u308b\u306e\u304c\u300c\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u300d\u3068\u300c\u30ed\u30c3\u30af\u300d\u306e\u6982\u5ff5\u3067\u3059\u3002<\/p>\n<h3>\u306a\u305c\u30ed\u30c3\u30af\u304c\u5fc5\u8981\u306a\u306e\u304b\uff1f\uff1a\u5171\u6709\u30ed\u30c3\u30af\u3068\u6392\u4ed6\u30ed\u30c3\u30af<\/h3>\n<p>\u30ed\u30c3\u30af\u3068\u306f\u3001\u7279\u5b9a\u306e\u30ea\u30bd\u30fc\u30b9\uff08\u30c6\u30fc\u30d6\u30eb\u3084\u884c\uff09\u306b\u4ed6\u306e\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u304c\u30a2\u30af\u30bb\u30b9\u3059\u308b\u306e\u3092\u5236\u9650\u3059\u308b\u4ed5\u7d44\u307f\u3067\u3059\u3002\u6700\u3082\u57fa\u672c\u7684\u306a\u30ed\u30c3\u30af\u306b\u300c\u5171\u6709\u30ed\u30c3\u30af\u300d\u3068\u300c\u6392\u4ed6\u30ed\u30c3\u30af\u300d\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<ul>\n<li><strong>\u5171\u6709\u30ed\u30c3\u30af (Shared Lock)<\/strong>\n<ul>\n<li>\u4e3b\u306b\u30c7\u30fc\u30bf\u306e<strong>\u8aad\u307f\u53d6\u308a\uff08<code>SELECT<\/code>\uff09<\/strong>\u6642\u306b\u7372\u5f97\u3057\u307e\u3059\u3002<\/li>\n<li>\u4ed6\u306e\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u3082\u5171\u6709\u30ed\u30c3\u30af\u3092\u7372\u5f97\u3057\u3066<strong>\u8aad\u307f\u53d6\u308b\u3053\u3068\u306f\u53ef\u80fd<\/strong>\u3067\u3059\u3002<\/li>\n<li>\u305f\u3060\u3057\u3001\u4ed6\u306e\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u304c\u6392\u4ed6\u30ed\u30c3\u30af\u3092\u7372\u5f97\u3057\u3066<strong>\u66f4\u65b0\u3059\u308b\u3053\u3068\u306f\u3067\u304d\u307e\u305b\u3093<\/strong>\u3002<\/li>\n<li><strong>\u4f8b\u3048\u308b\u306a\u3089<\/strong>: \u56f3\u66f8\u9928\u3067\u4ed6\u306e\u4eba\u3082\u95b2\u89a7\u3067\u304d\u308b\u3088\u3046\u306b\u300c\u9928\u5185\u95b2\u89a7\u4e2d\u300d\u306e\u672d\u3092\u7acb\u3066\u3066\u672c\u3092\u8aad\u3093\u3067\u3044\u308b\u72b6\u614b\u3002<\/li>\n<\/ul>\n<\/li>\n<li><strong>\u6392\u4ed6\u30ed\u30c3\u30af (Exclusive Lock)<\/strong>\n<ul>\n<li>\u4e3b\u306b\u30c7\u30fc\u30bf\u306e<strong>\u66f4\u65b0\uff08<code>INSERT<\/code>, <code>UPDATE<\/code>, <code>DELETE<\/code>\uff09<\/strong>\u6642\u306b\u7372\u5f97\u3057\u307e\u3059\u3002<\/li>\n<li>\u4ed6\u306e\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u306f\u3001\u5171\u6709\u30ed\u30c3\u30af\u3082\u6392\u4ed6\u30ed\u30c3\u30af\u3082\u7372\u5f97\u3067\u304d\u305a\u3001<strong>\u8aad\u307f\u53d6\u308a\u3082\u66f4\u65b0\u3082\u3067\u304d\u307e\u305b\u3093<\/strong>\u3002<\/li>\n<li><strong>\u4f8b\u3048\u308b\u306a\u3089<\/strong>: \u305d\u306e\u672c\u3092\u81ea\u5206\u3067\u4fee\u6b63\u3059\u308b\u305f\u3081\u306b\u300c\u7de8\u96c6\u4e2d\u300d\u306e\u672d\u3092\u7acb\u3066\u3066\u8cb8\u3057\u5207\u308a\u306b\u3057\u3066\u3044\u308b\u72b6\u614b\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>\u3053\u306e2\u3064\u306e\u30ed\u30c3\u30af\u306e\u95a2\u4fc2\u6027\u306f\u3001\u4ee5\u4e0b\u306e\u300c\u4e21\u7acb\u6027\u30de\u30c8\u30ea\u30af\u30b9\u300d\u3067\u6574\u7406\u3067\u304d\u307e\u3059\u3002<\/p>\n<table>\n<thead>\n<tr>\n<th>\u8981\u6c42\u3059\u308b\u30ed\u30c3\u30af<\/th>\n<th>\u65e2\u5b58\u306e\u30ed\u30c3\u30af\uff08\u5171\u6709\uff09<\/th>\n<th>\u65e2\u5b58\u306e\u30ed\u30c3\u30af\uff08\u6392\u4ed6\uff09<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>\u5171\u6709\u30ed\u30c3\u30af<\/strong><\/td>\n<td>\u25cb\uff08\u4e21\u7acb\u3059\u308b\uff09<\/td>\n<td>\u00d7\uff08\u7af6\u5408\u3059\u308b\uff09<\/td>\n<\/tr>\n<tr>\n<td><strong>\u6392\u4ed6\u30ed\u30c3\u30af<\/strong><\/td>\n<td>\u00d7\uff08\u7af6\u5408\u3059\u308b\uff09<\/td>\n<td>\u00d7\uff08\u7af6\u5408\u3059\u308b\uff09<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>\u6700\u60aa\u306e\u4e8b\u614b\u300c\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u300d\u3068\u305d\u306e\u56de\u907f\u7b56<\/h3>\n<p>\u30ed\u30c3\u30af\u306f\u30c7\u30fc\u30bf\u6574\u5408\u6027\u3092\u4fdd\u3064\u305f\u3081\u306b\u4e0d\u53ef\u6b20\u3067\u3059\u304c\u3001\u8907\u6570\u306e\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u304c\u4e92\u3044\u306b\u76f8\u624b\u306e\u30ed\u30c3\u30af\u89e3\u9664\u3092\u5f85\u3061\u3001\u6c38\u4e45\u306b\u51e6\u7406\u304c\u9032\u307e\u306a\u304f\u306a\u308b\u300c\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u300d\u3068\u3044\u3046\u6700\u60aa\u306e\u4e8b\u614b\u3092\u5f15\u304d\u8d77\u3053\u3059\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<div class=\"mermaid-diagram\">\n<p><strong>[\u56f3\u89e3: \u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u306e\u767a\u751f\u30e1\u30ab\u30cb\u30ba\u30e0]<\/strong><\/p>\n<pre><code>sequenceDiagram\n participant TX-A as \u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3A\n participant TX-B as \u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3B\n participant R-X as \u30ea\u30bd\u30fc\u30b9X\n participant R-Y as \u30ea\u30bd\u30fc\u30b9Y\n\n TX-A ->> R-X: lock(X)\n Note right of TX-A: \u6210\u529f\n TX-B ->> R-Y: lock(Y)\n Note right of TX-B: \u6210\u529f\n\n TX-A ->> R-Y: lock(Y)\n Note right of TX-A: B\u304cY\u3092\u30ed\u30c3\u30af\u4e2d\u306e\u305f\u3081\u5f85\u6a5f\n\n TX-B ->> R-X: lock(X)\n Note right of TX-B: A\u304cX\u3092\u30ed\u30c3\u30af\u4e2d\u306e\u305f\u3081\u5f85\u6a5f\n\n Note over TX-A, TX-B: \u4e92\u3044\u306b\u76f8\u624b\u306e\u30ed\u30c3\u30af\u89e3\u9664\u3092\u5f85\u3061\u3001\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u767a\u751f\uff01<\/code><\/pre>\n<\/div>\n<p><strong>\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u3092\u56de\u907f\u3059\u308b\u305f\u3081\u306e\u4e3b\u306a\u6226\u7565<\/strong><\/p>\n<ol>\n<li><strong>\u30ea\u30bd\u30fc\u30b9\u306e\u30ed\u30c3\u30af\u9806\u5e8f\u3092\u7d71\u4e00\u3059\u308b<\/strong>:<br \/>\n \u8907\u6570\u306e\u30c6\u30fc\u30d6\u30eb\u3092\u66f4\u65b0\u3059\u308b\u5834\u5408\u3001\u5fc5\u305a\u540c\u3058\u9806\u5e8f\uff08\u4f8b: \u5fc5\u305a<code>\u30c6\u30fc\u30d6\u30ebA<\/code> \u2192 <code>\u30c6\u30fc\u30d6\u30ebB<\/code>\uff09\u3067\u30ed\u30c3\u30af\u3092\u53d6\u5f97\u3059\u308b\u30eb\u30fc\u30eb\u3092\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u5168\u4f53\u3067\u5fb9\u5e95\u3057\u307e\u3059\u3002<\/li>\n<li><strong>\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u3092\u77ed\u304f\u3001\u30b7\u30f3\u30d7\u30eb\u306b\u4fdd\u3064<\/strong>:<br \/>\n \u30ed\u30c3\u30af\u3092\u4fdd\u6301\u3059\u308b\u6642\u9593\u304c\u9577\u304f\u306a\u308b\u307b\u3069\u3001\u4ed6\u306e\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u3068\u306e\u7af6\u5408\u3084\u30c7\u30c3\u30c9\u30ed\u30c3\u30af\u306e\u30ea\u30b9\u30af\u304c\u9ad8\u307e\u308a\u307e\u3059\u3002\u4e0d\u8981\u306a\u51e6\u7406\u306f\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u306e\u5916\u306b\u51fa\u3057\u307e\u3057\u3087\u3046\u3002<\/li>\n<li><strong>\u660e\u793a\u7684\u306a\u30ed\u30c3\u30af\u3068\u5206\u96e2\u30ec\u30d9\u30eb\u306e\u7406\u89e3<\/strong>:<br \/>\n \u5728\u5eab\u5f15\u304d\u5f53\u3066\u51e6\u7406\u306e\u3088\u3046\u306b\u7af6\u5408\u304c\u60f3\u5b9a\u3055\u308c\u308b\u5834\u9762\u3067\u306f\u3001<code>SELECT ... FOR UPDATE<\/code> \u3092\u7528\u3044\u3066\u4e8b\u524d\u306b\u884c\u3092\u30ed\u30c3\u30af\u3057\u3001\u66f4\u65b0\u306e\u885d\u7a81\u3092\u9632\u3050\u624b\u6cd5\u304c\u6709\u52b9\u3067\u3059\u3002\u307e\u305f\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u304c\u63d0\u4f9b\u3059\u308b\u300c\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u5206\u96e2\u30ec\u30d9\u30eb\u300d\u3092\u9069\u5207\u306b\u8a2d\u5b9a\u3059\u308b\u3053\u3068\u3082\u3001\u7af6\u5408\u3092\u30b3\u30f3\u30c8\u30ed\u30fc\u30eb\u3059\u308b\u4e0a\u3067\u91cd\u8981\u3067\u3059\u3002<\/li>\n<\/ol>\n<p><\/body><br \/>\n<\/html><\/p>\n<h2>\u30c7\u30fc\u30bf\u306e\u77db\u76fe\u3092\u9632\u3050\u756a\u4eba\uff01\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306e\u5236\u7d04\u3068\u6b63\u898f\u5316\u306e\u57fa\u790e<\/h2>\n<p>\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u304c\u6b63\u3057\u304f\u6a5f\u80fd\u3059\u308b\u305f\u3081\u306e\u5927\u524d\u63d0\u306f\u3001\u305d\u306e\u571f\u53f0\u3068\u306a\u308b\u30c7\u30fc\u30bf\u304c\u300c\u6b63\u3057\u304f\u3001\u77db\u76fe\u304c\u306a\u3044\u72b6\u614b\u300d\u3067\u3042\u308b\u3053\u3068\u3067\u3059\u3002\u4f8b\u3048\u3070\u3001\u5b58\u5728\u3057\u306a\u3044\u306f\u305a\u306e\u5546\u54c1ID\u3092\u6301\u3064\u6ce8\u6587\u30ec\u30b3\u30fc\u30c9\u3084\u3001\u5fc5\u9808\u3067\u3042\u308b\u306f\u305a\u306e\u30e6\u30fc\u30b6\u30fc\u540d\u304c\u7a7a\u306e\u9867\u5ba2\u30c7\u30fc\u30bf\u304c\u5b58\u5728\u3059\u308c\u3070\u3001\u30b7\u30b9\u30c6\u30e0\u306f\u6df1\u523b\u306a\u4e0d\u5177\u5408\u3092\u5f15\u304d\u8d77\u3053\u3057\u307e\u3059\u3002\u3053\u306e\u3088\u3046\u306a\u4e8b\u614b\u3092\u9632\u304e\u3001\u30c7\u30fc\u30bf\u306e\u54c1\u8cea\u3092\u4fdd\u8a3c\u3059\u308b\u4ed5\u7d44\u307f\u304c\u300c\u30c7\u30fc\u30bf\u6574\u5408\u6027\u300d\u306e\u78ba\u4fdd\u3067\u3059\u3002<\/p>\n<h3>\u30c7\u30fc\u30bf\u306e\u9580\u756a\u300c\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u5236\u7d04\u300d<\/h3>\n<p>\u30c7\u30fc\u30bf\u6574\u5408\u6027\u3092\u5b88\u308b\u305f\u3081\u306e\u6700\u3082\u76f4\u63a5\u7684\u3067\u5f37\u529b\u306a\u6a5f\u80fd\u304c\u300c\u5236\u7d04\uff08Constraint\uff09\u300d\u3067\u3059\u3002\u5236\u7d04\u306f\u3001\u30c6\u30fc\u30d6\u30eb\u5b9a\u7fa9\u306e\u969b\u306b\u8a2d\u5b9a\u3059\u308b\u300c\u30eb\u30fc\u30eb\u300d\u3067\u3042\u308a\u3001\u3053\u306e\u30eb\u30fc\u30eb\u306b\u9055\u53cd\u3059\u308b\u30c7\u30fc\u30bf\u306e<code>INSERT<\/code>\u3084<code>UPDATE<\/code>\u3092\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u81ea\u8eab\u304c\u30d6\u30ed\u30c3\u30af\u3057\u3066\u304f\u308c\u307e\u3059\u3002\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u5074\u306e\u5b9f\u88c5\u30df\u30b9\u306b\u3088\u308b\u4e0d\u6b63\u306a\u30c7\u30fc\u30bf\u6df7\u5165\u3092\u9632\u3050\u305f\u3081\u306e\u6700\u5f8c\u306e\u7826\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n<table>\n<thead>\n<tr>\n<th>\u4e3b\u8981\u306a\u5236\u7d04<\/th>\n<th>\u5f79\u5272\u3068\u5177\u4f53\u4f8b<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>\u4e3b\u30ad\u30fc (PRIMARY KEY)<\/strong><\/td>\n<td>\u5404\u884c\u3092\u4e00\u610f\u306b\u8b58\u5225\u3059\u308b\u305f\u3081\u306e\u5236\u7d04\u3002<code>NULL<\/code>\u306f\u8a31\u53ef\u3055\u308c\u305a\u3001\u91cd\u8907\u3082\u8a31\u3055\u308c\u307e\u305b\u3093\u3002<br \/>\u4f8b\uff1a\u5f93\u696d\u54e1\u30c6\u30fc\u30d6\u30eb\u306e\u300c\u5f93\u696d\u54e1ID\u300d<\/td>\n<\/tr>\n<tr>\n<td><strong>\u5916\u90e8\u30ad\u30fc (FOREIGN KEY)<\/strong><\/td>\n<td>\u4ed6\u306e\u30c6\u30fc\u30d6\u30eb\u306e\u4e3b\u30ad\u30fc\u3092\u53c2\u7167\u3059\u308b\u5236\u7d04\u3002\u95a2\u9023\u5148\u306e\u30c6\u30fc\u30d6\u30eb\u306b\u5b58\u5728\u3057\u306a\u3044\u5024\u306e\u767b\u9332\u3092\u9632\u304e\u307e\u3059\u3002<br \/>\u4f8b\uff1a\u6ce8\u6587\u30c6\u30fc\u30d6\u30eb\u306e\u300c\u9867\u5ba2ID\u300d\u306f\u3001\u5fc5\u305a\u9867\u5ba2\u30c6\u30fc\u30d6\u30eb\u306b\u5b58\u5728\u3059\u308bID\u3067\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\u3002<\/td>\n<\/tr>\n<tr>\n<td><strong>\u4e00\u610f\u6027 (UNIQUE)<\/strong><\/td>\n<td>\u6307\u5b9a\u3057\u305f\u5217\u306e\u5024\u304c\u30c6\u30fc\u30d6\u30eb\u5185\u3067\u91cd\u8907\u3057\u306a\u3044\u3053\u3068\u3092\u4fdd\u8a3c\u3057\u307e\u3059\u3002<br \/>\u4f8b\uff1a\u30e6\u30fc\u30b6\u30fc\u30c6\u30fc\u30d6\u30eb\u306e\u300c\u30e1\u30fc\u30eb\u30a2\u30c9\u30ec\u30b9\u300d<\/td>\n<\/tr>\n<tr>\n<td><strong>\u975eNULL (NOT NULL)<\/strong><\/td>\n<td>\u6307\u5b9a\u3057\u305f\u5217\u306b<code>NULL<\/code>\u5024\u304c\u5165\u308b\u3053\u3068\u3092\u7981\u6b62\u3057\u307e\u3059\u3002<br \/>\u4f8b\uff1a\u4f1a\u54e1\u767b\u9332\u30d5\u30a9\u30fc\u30e0\u3067\u300c\u6c0f\u540d\u300d\u306e\u5165\u529b\u306f\u5fc5\u9808\u3002<\/td>\n<\/tr>\n<tr>\n<td><strong>\u691c\u67fb (CHECK)<\/strong><\/td>\n<td>\u6307\u5b9a\u3057\u305f\u5217\u306e\u5024\u304c\u3001\u7279\u5b9a\u306e\u6761\u4ef6\u3092\u6e80\u305f\u3059\u3053\u3068\u3092\u4fdd\u8a3c\u3057\u307e\u3059\u3002<br \/>\u4f8b\uff1a\u5546\u54c1\u30c6\u30fc\u30d6\u30eb\u306e\u300c\u4fa1\u683c\u300d\u306f\u5fc5\u305a0\u4ee5\u4e0a\u3067\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>\u3010\u30b3\u30fc\u30c9\u4f8b: \u5236\u7d04\u3092\u5229\u7528\u3057\u305f\u30c6\u30fc\u30d6\u30eb\u4f5c\u6210\u3011<\/strong><\/p>\n<pre><code>CREATE TABLE employees (\n employee_id INTEGER PRIMARY KEY,\n email VARCHAR(255) NOT NULL UNIQUE,\n name VARCHAR(100) NOT NULL,\n department_id INTEGER REFERENCES departments(department_id), -- \u5916\u90e8\u30ad\u30fc\n salary INTEGER CHECK (salary >= 0)\n);<\/code><\/pre>\n<h3>\u8a2d\u8a08\u306e\u571f\u53f0\u300c\u6b63\u898f\u5316\u300d<\/h3>\n<p>\u6b63\u898f\u5316\u3068\u306f\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u8a2d\u8a08\u6642\u306b\u30c7\u30fc\u30bf\u306e\u91cd\u8907\u3092\u306a\u304f\u3057\u3001\u6574\u5408\u6027\u3092\u4fdd\u3061\u3084\u3059\u3044\u3088\u3046\u306b\u30c6\u30fc\u30d6\u30eb\u3092\u5206\u5272\u30fb\u6574\u7406\u3057\u3066\u3044\u304f\u30d7\u30ed\u30bb\u30b9\u3067\u3059\u3002\u6b63\u898f\u5316\u3092\u884c\u3046\u3053\u3068\u3067\u3001\u300c\u66f4\u65b0\u6f0f\u308c\u300d\u306e\u3088\u3046\u306a\u4eba\u70ba\u7684\u30df\u30b9\uff08\u66f4\u65b0\u7570\u5e38\uff09\u3092\u9632\u304e\u3001\u30c7\u30fc\u30bf\u3092\u52b9\u7387\u7684\u306b\u7ba1\u7406\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p><strong>\u4f8b\u3048\u308b\u306a\u3089\u3001\u300c\u4f4f\u6240\u9332\u300d\u306e\u6574\u7406\u3067\u3059\u3002<\/strong> \u8907\u6570\u306e\u30ea\u30b9\u30c8\u306b\u53cb\u4eba\u306e\u53e4\u3044\u4f4f\u6240\u3068\u65b0\u3057\u3044\u4f4f\u6240\u304c\u6df7\u5728\u3057\u3066\u3044\u308b\u3068\u3001\u3069\u3061\u3089\u304c\u6b63\u3057\u3044\u304b\u5206\u304b\u3089\u306a\u304f\u306a\u308a\u307e\u3059\u3002\u3053\u308c\u3092\u300c\u4f4f\u6240\u9332\u300d\u3068\u3044\u3046\u30de\u30b9\u30bf\u30fc\u30c7\u30fc\u30bf\u3092\u4e00\u3064\u3060\u3051\u4f5c\u308a\u3001\u4ed6\u306e\u30ea\u30b9\u30c8\u304b\u3089\u306f\u305d\u306e\u30de\u30b9\u30bf\u30fc\u3092\u53c2\u7167\u3059\u308b\u5f62\u306b\u3059\u308c\u3070\u3001\u4f4f\u6240\u5909\u66f4\u306f\u30de\u30b9\u30bf\u30fc\u306e1\u30f6\u6240\u3092\u4fee\u6b63\u3059\u308b\u3060\u3051\u3067\u6e08\u307f\u307e\u3059\u3002<\/p>\n<div class=\"mermaid-diagram\">\n<p><strong>[\u56f3\u89e3: \u975e\u6b63\u898f\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u6b63\u898f\u5316\u3055\u308c\u305f\u30c6\u30fc\u30d6\u30eb\u3078\u306e\u5206\u5272]<\/strong><\/p>\n<pre><code>graph TD\n subgraph Before (\u975e\u6b63\u898f)\n T1[\"\u6ce8\u6587\u30c6\u30fc\u30d6\u30eb\\n(\u6ce8\u6587ID, \u6ce8\u6587\u65e5, \u9867\u5ba2ID, <b>\u9867\u5ba2\u540d<\/b>, <b>\u9867\u5ba2\u4f4f\u6240<\/b>, \u5546\u54c1ID, <b>\u5546\u54c1\u540d<\/b>, <b>\u5358\u4fa1<\/b>, \u6570\u91cf)\"]\n end\n\n subgraph After (\u6b63\u898f\u5316)\n T2[\u9867\u5ba2\u30c6\u30fc\u30d6\u30eb\\n(<u>\u9867\u5ba2ID<\/u>, \u9867\u5ba2\u540d, \u9867\u5ba2\u4f4f\u6240)]\n T3[\u5546\u54c1\u30c6\u30fc\u30d6\u30eb\\n(<u>\u5546\u54c1ID<\/u>, \u5546\u54c1\u540d, \u5358\u4fa1)]\n T4[\u6ce8\u6587\u30c6\u30fc\u30d6\u30eb\\n(<u>\u6ce8\u6587ID<\/u>, \u6ce8\u6587\u65e5, \u9867\u5ba2ID(FK), \u5546\u54c1ID(FK), \u6570\u91cf)]\n end\n\n T1 -- \u5206\u5272 --> T2;\n T1 -- \u5206\u5272 --> T3;\n T1 -- \u5206\u5272 --> T4;\n\n T4 -- \u53c2\u7167 --> T2;\n T4 -- \u53c2\u7167 --> T3;<\/code><\/pre>\n<\/div>\n<p>\u5b9f\u52d9\u3067\u306f\u591a\u304f\u306e\u5834\u5408\u3001<strong>\u7b2c3\u6b63\u898f\u5f62\uff083NF\uff09<\/strong> 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