{"id":6916,"date":"2024-03-19T15:31:56","date_gmt":"2024-03-19T06:31:56","guid":{"rendered":"https:\/\/techmania.jp\/blog\/?p=6916"},"modified":"2024-07-19T20:30:19","modified_gmt":"2024-07-19T11:30:19","slug":"sql-foreign-key","status":"publish","type":"post","link":"https:\/\/techmania.jp\/blog\/sql-foreign-key\/","title":{"rendered":"\u3010SQL\u3011\u5916\u90e8\u30ad\u30fc\u3068\u306f\uff1f\u4e3b\u30ad\u30fc\u3068\u306e\u95a2\u4fc2\u3084\u66f8\u304d\u65b9\u3092\u89e3\u8aac"},"content":{"rendered":"

\u5916\u90e8\u30ad\u30fc\u3092\u8a2d\u5b9a\u3059\u308c\u3070\u30c6\u30fc\u30d6\u30eb\u9593\u306e\u30c7\u30fc\u30bf\u306e\u95a2\u9023\u6027\u3092\u8868\u73fe\u3067\u304d\u3001\u30c7\u30fc\u30bf\u3092\u66f4\u65b0\u30fb\u524a\u9664\u3059\u308b\u969b\u306b\u3082\u6574\u5408\u6027\u3092\u4fdd\u3064\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u672c\u8a18\u4e8b\u3067\u306f\u5916\u90e8\u30ad\u30fc\u306e\u6982\u8981\u304b\u3089\u4f5c\u6210\u65b9\u6cd5\u307e\u3067\u57fa\u790e\u304b\u3089\u89e3\u8aac\u3057\u307e\u3059\u3002<\/span><\/span><\/p>\n\n\n

\u5916\u90e8\u30ad\u30fc\u3068\u306f<\/h2>\n\n\n

SQL\u306e\u5916\u90e8\u30ad\u30fc\uff08Foreign Key\uff09\u3068\u306f\u3001\u30c7\u30fc\u30bf\u3092\u8ffd\u52a0\u30fb\u66f4\u65b0\u30fb\u524a\u9664\u3059\u308b\u969b\u3001\u30c6\u30fc\u30d6\u30eb\u9593\u3067\u5236\u7d04\u3092\u8a2d\u3051\u308b\u3053\u3068\u3067\u3001\u89aa\u30c6\u30fc\u30d6\u30eb\u306b\u5b58\u5728\u3057\u306a\u3044\u30c7\u30fc\u30bf\u3092\u5b50\u30c6\u30fc\u30d6\u30eb\u304c\u6301\u3064\u3053\u3068\u304c\u306a\u3044\u3088\u3046\u306b\u3059\u308b\u4ed5\u7d44\u307f\u3067\u3059\u3002\u5916\u90e8\u30ad\u30fc\u3092\u8a2d\u5b9a\u3059\u308b\u3053\u3068\u3067\u3001\u30c6\u30fc\u30d6\u30eb\u9593\u306e\u30c7\u30fc\u30bf\u306e\u95a2\u9023\u6027\u3092\u8868\u73fe\u3057\u3001\u30c7\u30fc\u30bf\u3092\u8ffd\u52a0\u30fb\u66f4\u65b0\u30fb\u524a\u9664\u3059\u308b\u969b\u306b\u6574\u5408\u6027\u3092\u4fdd\u3066\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n

\u5916\u90e8\u30ad\u30fc\u306e\u4ed5\u7d44\u307f<\/h3>\n\n\n

\u5916\u90e8\u30ad\u30fc\u3092\u8a2d\u5b9a\u3059\u308b\u3068\u30012\u3064\u306e\u30c6\u30fc\u30d6\u30eb\u9593\u3067\u3001\u30c7\u30fc\u30bf\u306e\u53c2\u7167\u5148\u3068\u53c2\u7167\u5143\u3067\u89aa\u5b50\u95a2\u4fc2\u304c\u6210\u308a\u7acb\u3061\u307e\u3059\u3002\u306a\u304a\u3001\u53c2\u7167\u5148\u3092\u89aa\u30c6\u30fc\u30d6\u30eb\uff08\u30de\u30b9\u30bf\u30fc\u30c6\u30fc\u30d6\u30eb\uff09\u3001\u53c2\u7167\u5143\u3092\u5b50\u30c6\u30fc\u30d6\u30eb\uff08\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u30c6\u30fc\u30d6\u30eb\uff09\u3068\u3044\u3044\u307e\u3059\u3002\u53c2\u7167\u5143\uff08\u5b50\u30c6\u30fc\u30d6\u30eb\/\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u30c6\u30fc\u30d6\u30eb\uff09\u306e\u30ab\u30e9\u30e0\u306b\u5916\u90e8\u30ad\u30fc\u5236\u7d04\u3092\u8a2d\u5b9a\u3059\u308b\u3068\u3001\u53c2\u7167\u5148\uff08\u89aa\u30c6\u30fc\u30d6\u30eb\/\u30de\u30b9\u30bf\u30fc\u30c6\u30fc\u30d6\u30eb\uff09\u306e\u6307\u5b9a\u3057\u305f\u30ab\u30e9\u30e0\u306b\u3042\u308b\u5024\u3057\u304b\u6307\u5b9a\u3067\u304d\u306a\u3044\u3088\u3046\u5236\u9650\u3055\u308c\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u3001\u89aa\u30c6\u30fc\u30d6\u30eb\u306b\u5b58\u5728\u3057\u306a\u3044\u5024\u3092\u5b50\u30c6\u30fc\u30d6\u30eb\u306e\u30ab\u30e9\u30e0\u306b\u8ffd\u52a0\u3057\u3088\u3046\u3068\u3057\u305f\u308a\u3001\u5b50\u30c6\u30fc\u30d6\u30eb\u3067\u767b\u9332\u306e\u3042\u308b\u5024\u3092\u89aa\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u524a\u9664\u3057\u3088\u3046\u3068\u3059\u308b\u3068\u30a8\u30e9\u30fc\u306b\u306a\u308a\u307e\u3059\u3002<\/span><\/span><\/p>\n

\u305f\u3068\u3048\u3070\u3001\u90e8\u7f72\u30c6\u30fc\u30d6\u30eb\u3068\u5f93\u696d\u54e1\u30c6\u30fc\u30d6\u30eb\u304c\u3042\u308b\u5834\u5408\u3001\u5f93\u696d\u54e1\u30c6\u30fc\u30d6\u30eb\u306e\u90e8\u7f72\u6b04\u306b\u306f\u90e8\u7f72\u30c6\u30fc\u30d6\u30eb\u306b\u767b\u9332\u3055\u308c\u3066\u3044\u306a\u3044\u90e8\u7f72ID\u3092\u767b\u9332\u3067\u304d\u306a\u3044\u3068\u3044\u3046\u3088\u3046\u306a\u611f\u3058\u3067\u3059\u3002\u5f8c\u307b\u3069\u8a73\u3057\u304f\u7d39\u4ecb\u3057\u307e\u3059\u3002<\/p>\n\n\n

\u5916\u90e8\u30ad\u30fc\u306e\u5177\u4f53\u4f8b<\/h3>\n\n\n

\u300c\u5b50\u30c6\u30fc\u30d6\u30eb\u304c\u89aa\u30c6\u30fc\u30d6\u30eb\u306b\u5b58\u5728\u3057\u306a\u3044\u5024\u3092\u6301\u3064\u3053\u3068\u304c\u306a\u3044\u3088\u3046\u306b\u3059\u308b\u300d\u3092\u308f\u304b\u308a\u3084\u3059\u304f\u5177\u4f53\u4f8b\u3067\u8aac\u660e\u3057\u307e\u3059\u3002<\/p>\n

\u305f\u3068\u3048\u3070\u3001\u4e0b\u8a18\u306e\u3088\u3046\u306b\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u3068\u300c\u5f93\u696d\u54e1\u300d\u30c6\u30fc\u30d6\u30eb\u304c\u3042\u308b\u3068\u3057\u307e\u3059\u3002<\/p>\n

\u300c\u5f93\u696d\u54e1\u300d\u30c6\u30fc\u30d6\u30eb\u306e\u300c\u90e8\u7f72ID\u300d\u30ab\u30e9\u30e0\u306b\u5bfe\u3057\u3001\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u306e\u300cID\u300d\u30ab\u30e9\u30e0\u3092\u6307\u5b9a\u3057\u3066\u5916\u90e8\u30ad\u30fc\u3092\u8a2d\u5b9a\u3057\u307e\u3059\u3002<\/p>\n\n\n\n\n\n

\u3059\u308b\u3068\u3001\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u306b\u5b58\u5728\u3057\u306a\u3044\u300c\u90e8\u7f72ID\u300d\u3092\u300c\u5f93\u696d\u54e1\u300d\u30c6\u30fc\u30d6\u30eb\u306b\u767b\u9332\u3067\u304d\u306a\u3044\u3088\u3046\u306b\u306a\u308a\u3001\u3053\u306e2\u3064\u306e\u30ab\u30e9\u30e0\u3067\u6574\u5408\u6027\u304c\u4fdd\u305f\u308c\u307e\u3059\u3002<\/p>\n

\u3064\u307e\u308a\u3001\u300c\u5f93\u696d\u54e1\u300d\u30c6\u30fc\u30d6\u30eb\u306e\u300c\u90e8\u7f72ID\u300d\u30ab\u30e9\u30e0\u306b\u306f\u3001\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u306e\u300cID\u300d\u30ab\u30e9\u30e0\u306e\u300c1\uff5e6\u300d\u306e\u5024\u3057\u304b\u767b\u9332\u3067\u304d\u306a\u3044\u3068\u3044\u3046\u3053\u3068\u3067\u3059\u306d\uff01<\/p>\n\n\n

\u5916\u90e8\u30ad\u30fc\u3068\u4e3b\u30ad\u30fc\u306e\u95a2\u4fc2\u6027<\/h3>\n\n\n

\u4e3b\u30ad\u30fc\uff08\u30d7\u30e9\u30a4\u30de\u30ea\u30fc\u30ad\u30fc\uff09<\/a>\u3068\u306f\u3001\u30ec\u30b3\u30fc\u30c9\u306e\u3046\u3061\u3001\u30ec\u30b3\u30fc\u30c9\u3092\u4e00\u610f\u306b\u8b58\u5225\u3059\u308b\u5f79\u5272\u306e\u3042\u308b\u30ab\u30e9\u30e0\u3067\u3059\u3002\u6570\u5024\u578b\u306e\u30ab\u30e9\u30e0\u3092\u9078\u3076\u306e\u304c\u4e00\u822c\u7684\u3067\u3059\u304c\u3001\u6587\u5b57\u5217\u3084\u65e5\u4ed8\u306a\u3069\u3067\u3082\u554f\u984c\u3042\u308a\u307e\u305b\u3093\u3002\u5148\u307b\u3069\u306e\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u3067\u3044\u3046\u3068\u300cID\u300d\u30ab\u30e9\u30e0\u3001\u300c\u5f93\u696d\u54e1\u300d\u30c6\u30fc\u30d6\u30eb\u3067\u3044\u3046\u3068\u300c\u5f93\u696d\u54e1ID\u300d\u30ab\u30e9\u30e0\u304c\u4e3b\u30ad\u30fc\u306b\u9069\u3057\u3066\u3044\u307e\u3059\u3002\u540c\u59d3\u540c\u540d\u306e\u793e\u54e1\u3084\u540c\u3058\u90e8\u7f72\u306e\u5f93\u696d\u54e1\u304c\u3044\u3066\u3082\u5f93\u696d\u54e1ID\u3067\u5f93\u696d\u54e1\u3092\u8b58\u5225\u30fb\u7ba1\u7406\u3067\u304d\u307e\u3059\u3002<\/span>
<\/span><\/p>\n

\u305d\u3057\u3066\u3001\u3053\u306e\u4e3b\u30ad\u30fc\u3092\u53c2\u7167\u3059\u308b\u306e\u304c\u5916\u90e8\u30ad\u30fc\u3067\u3059\u3002\u5916\u90e8\u30ad\u30fc\u306f\u3001\u30c6\u30fc\u30d6\u30eb\u4f5c\u6210\u6642\u306b\u53c2\u7167\u5143\u306e\u5b50\u30c6\u30fc\u30d6\u30eb\u306b\u3064\u3051\u307e\u3059\u3002\u307e\u305f\u3001\u53c2\u7167\u5148\uff08\u89aa\u30c6\u30fc\u30d6\u30eb\uff09\u306e\u30ab\u30e9\u30e0\u306f\u3001\u305d\u306e\u30c6\u30fc\u30d6\u30eb\u306e\u4e3b\u30ad\u30fc\u3067\u3042\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u308c\u306f\u4e3b\u30ad\u30fc\u304c\u4e00\u610f\u3067\u3042\u308a\u3001\u304b\u3064NULL\u5024\uff08\u5024\u304c\u5b58\u5728\u3057\u306a\u3044\u72b6\u614b\uff09\u3067\u306f\u3044\u3051\u306a\u3044\u3068\u3044\u3046\u30eb\u30fc\u30eb\u304c\u3042\u308b\u304b\u3089\u3067\u3059\u3002\u53c2\u7167\u5148\u306e\u30ab\u30e9\u30e0\u306b\u91cd\u8907\u3057\u305f\u30c7\u30fc\u30bf\u304c\u3042\u308b\u3068\u3069\u306e\u30c7\u30fc\u30bf\u3068\u7d50\u3073\u3064\u3051\u308b\u304b\u8b58\u5225\u3067\u304d\u307e\u305b\u3093\u3057\u3001NULL\u5024\u3067\u3082\u53c2\u7167\u3067\u304d\u307e\u305b\u3093\u3002<\/p>\n

\u3064\u307e\u308a\u3001\u4e0a\u8a18\u306e\u5834\u5408\u306f\u3001\u300c\u5f93\u696d\u54e1\u300d\u30c6\u30fc\u30d6\u30eb\u3067\u306f\u300c\u5f93\u696d\u54e1ID\u300d\u30ab\u30e9\u30e0\u304c\u4e3b\u30ad\u30fc\u3001\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u3067\u306f\u300cID\u300d\u30ab\u30e9\u30e0\u304c\u4e3b\u30ad\u30fc\u3001\u305d\u3057\u3066\u3001\u305d\u306e\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u3067\u306f\u300cID\u300d\u30ab\u30e9\u30e0\u3092\u53c2\u7167\u3059\u308b\u300c\u5f93\u696d\u54e1\u300d\u30c6\u30fc\u30d6\u30eb\u306e\u300c\u90e8\u7f72\u300d\u30ab\u30e9\u30e0\u304c\u5916\u90e8\u30ad\u30fc\u3068\u3044\u3046\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u306d\uff01<\/p>\n\n\n

\u5916\u90e8\u30ad\u30fc\u306e\u5236\u7d04<\/h2>\n\n\n

\u5916\u90e8\u30ad\u30fc\u3092\u8a2d\u5b9a\u3057\u305f\u5834\u5408\u3001\u4e0d\u6574\u5408\u3092\u9632\u3050\u305f\u3081\u306b\u4e0b\u8a18\u306e\u5236\u7d04\uff08\u53c2\u7167\u6574\u5408\u6027\u5236\u7d04\uff09\u304c\u5165\u308a\u307e\u3059\u3002<\/p>\n

\n

1. \u89aa\u30c6\u30fc\u30d6\u30eb\u306b\u5b58\u5728\u3057\u306a\u3044\u5024\u3092\u5b50\u30c6\u30fc\u30d6\u30eb\u306b\u767b\u9332\u3067\u304d\u306a\u3044<\/strong>
2. \u5b50\u30c6\u30fc\u30d6\u30eb\u306b\u767b\u9332\u3055\u308c\u3066\u3044\u308b\u5024\u3092\u89aa\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u524a\u9664\u3067\u304d\u306a\u3044
<\/strong><\/p>\n<\/div>\n

\u3053\u306e\u5236\u7d04\u306f\u53c2\u7167\u5143\u3068\u53c2\u7167\u5148\u3068\u3067\u6574\u5408\u6027\u304c\u53d6\u308c\u308b\u3088\u3046\u3001\u53c2\u7167\u5148\u306b\u5024\u304c\u5b58\u5728\u3059\u308b\u3053\u3068\u3092\u4fdd\u8a3c\u3059\u308b\u3082\u306e\u3067\u3059\u3002<\/p>\n

\u305d\u308c\u305e\u308c\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n

\u30b5\u30f3\u30d7\u30eb\u30c6\u30fc\u30d6\u30eb<\/h4>\n\n\n

\u8aac\u660e\u306b\u306f\u6b21\u306e\u30b5\u30f3\u30d7\u30eb\u30c6\u30fc\u30d6\u30eb\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002<\/p>\n

\u300c\u90e8\u7f72\uff08department\uff09\u300d\u30c6\u30fc\u30d6\u30eb<\/strong><\/p>\n\n\n

ID\uff08id\uff09<\/strong><\/td>\u90e8\u7f72\u540d\uff08dept_name\uff09<\/strong><\/td><\/tr>
1<\/td>\u7dcf\u52d9\u90e8<\/td><\/tr>
2<\/td>\u4eba\u4e8b\u90e8<\/td><\/tr>
3<\/td>\u7d4c\u7406\u90e8<\/td><\/tr>
4<\/td>\u55b6\u696d\u90e8<\/td><\/tr>
5<\/td>\u30de\u30fc\u30b1\u30c6\u30a3\u30f3\u30b0\u90e8<\/td><\/tr>
6<\/td>\u60c5\u5831\u30b7\u30b9\u30c6\u30e0\u90e8<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n

\u300c\u5f93\u696d\u54e1\uff08employee\uff09\u300d\u30c6\u30fc\u30d6\u30eb<\/strong><\/p>\n\n\n

\u5f93\u696d\u54e1ID\uff08employee_id\uff09<\/strong><\/td>\u6c0f\u540d\uff08name\uff09<\/strong><\/td>\u90e8\u7f72ID\uff08dept_id\uff09<\/strong><\/td><\/tr>
0001<\/td>\u963f\u90e8<\/td>5<\/td><\/tr>
0002<\/td>\u83ca\u6c60<\/td>1<\/td><\/tr>
0003<\/td>\u9234\u6728<\/td>6<\/td><\/tr>
0004<\/td>\u7530\u4e2d<\/td>4<\/td><\/tr>
0005<\/td>\u91ce\u6751<\/td>2<\/td><\/tr>
0006<\/td>\u9577\u8c37\u5ddd<\/td>1<\/td><\/tr>
0007<\/td>\u5897\u7530<\/td>3<\/td><\/tr>
0008<\/td>\u5c71\u7530<\/td>5<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n

\u3053\u306e\u6642\u3001\u53c2\u7167\u3055\u308c\u308b\u5074\u306e\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u304c\u89aa\u3001\u53c2\u7167\u3059\u308b\u5074\u306e\u300c\u5f93\u696d\u54e1\u300d\u30c6\u30fc\u30d6\u30eb\u304c\u5b50\u306b\u306a\u308a\u307e\u3059\u3002\u305f\u3068\u3048\u3070\u3001\u963f\u90e8\u3055\u3093\u306e\u90e8\u7f72\u3092\u77e5\u308a\u305f\u3044\u5834\u5408\u3001\u90e8\u7f72ID\u304c\u300c5\u300d\u306a\u306e\u3067\u3001\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u306e\u300cID\u300d\u9805\u76ee\u3092\u53c2\u7167\u3059\u308b\u3068\u300c\u30de\u30fc\u30b1\u30c6\u30a3\u30f3\u30b0\u90e8\u300d\u3067\u3042\u308b\u3053\u3068\u304c\u5206\u304b\u308a\u307e\u3059\u3002<\/p>\n\n\n

\u89aa\u30c6\u30fc\u30d6\u30eb\u306b\u5b58\u5728\u3057\u306a\u3044\u5024\u3092\u5b50\u30c6\u30fc\u30d6\u30eb\u306b\u767b\u9332\u3067\u304d\u306a\u3044<\/h3>\n\n\n

\u5b58\u5728\u3057\u306a\u3044\u5024\u3092\u5916\u90e8\u30ad\u30fc\u306b\u8a2d\u5b9a\u3067\u304d\u307e\u305b\u3093\u3002\u5b50\u30c6\u30fc\u30d6\u30eb\u306b\u89aa\u30c6\u30fc\u30d6\u30eb\u306b\u7121\u3044\u30c7\u30fc\u30bf\u3092\u8ffd\u52a0\u3059\u308b\u3068\u3001\u89aa\u5b50\u306e\u6574\u5408\u6027\u304c\u5d29\u308c\u3066\u3057\u307e\u3044\u307e\u3059\u3002\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u306b\u4e0b\u8a18\u306e\u3088\u3046\u306a\u30c7\u30fc\u30bf\u3092\u767b\u9332\u3059\u308b\u3068\u3057\u307e\u3059\u3002<\/p>\n\n\n

\u5f93\u696d\u54e1ID\uff08employee_id\uff09<\/strong><\/td>\u6c0f\u540d\uff08name\uff09<\/strong><\/td>\u90e8\u7f72ID\uff08dept_id\uff09<\/strong><\/td><\/tr>
0009<\/td>\u6e21\u8fba<\/td>7<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n

\u3010\u5b9f\u884c\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n

INSERT INTO employee VALUES(0009<\/strong>,'\u6e21\u8fba',7)<\/strong>;<\/code><\/pre>\n\n\n
\u3057\u304b\u3057\u3001\u89aa\u30c6\u30fc\u30d6\u30eb\u3067\u3042\u308b\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u306b\u306f\u53c2\u7167\u3059\u308b\u30c7\u30fc\u30bf\u304c\u306a\u3044\u306e\u3067\u3001\u300cparent key not found\u300d\u3068\u8a18\u8f09\u3055\u308c\u305f\u30a8\u30e9\u30fc\u304c\u51fa\u307e\u3059\u3002<\/p>\n\n\n
ID\uff08id\uff09<\/strong><\/td>\u90e8\u7f72\u540d\uff08dept_name\uff09<\/strong><\/td><\/tr>
1<\/td>\u7dcf\u52d9\u90e8<\/td><\/tr>
2<\/td>\u4eba\u4e8b\u90e8<\/td><\/tr>
3<\/td>\u7d4c\u7406\u90e8<\/td><\/tr>
4<\/td>\u55b6\u696d\u90e8<\/td><\/tr>
5<\/td>\u30de\u30fc\u30b1\u30c6\u30a3\u30f3\u30b0\u90e8<\/td><\/tr>
6<\/td>\u60c5\u5831\u30b7\u30b9\u30c6\u30e0\u90e8<\/td><\/tr>
7<\/td>NULL<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
<\/p>\n\n\n\n\n\n\n
\u3010\u5b9f\u884c\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n
DELETE FROM department WHERE id=1<\/strong>;<\/code><\/pre>\n\n\n\n
\u5b50\u30c6\u30fc\u30d6\u30eb\u306b\u767b\u9332\u3055\u308c\u3066\u3044\u308b\u5024\u3092\u89aa\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u524a\u9664\u3067\u304d\u306a\u3044<\/h3>\n\n\n
\u5b50\u30c6\u30fc\u30d6\u30eb\u306b\u5916\u90e8\u30ad\u30fc\u3068\u3057\u3066\u767b\u9332\u3055\u308c\u3066\u3044\u308b\u5024\u3092\u89aa\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u524a\u9664\u30fb\u66f4\u65b0\u3057\u3088\u3046\u3068\u3059\u308b\u3068\u300cchild record found\u300d\u3068\u8a18\u8f09\u3055\u308c\u305f\u30a8\u30e9\u30fc\u304c\u51fa\u307e\u3059\u3002<\/p>\n
\u89aa\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u30c7\u30fc\u30bf\u3092\u524a\u9664\u3059\u308b\u306b\u306f\u307e\u305a\u5b50\u30c6\u30fc\u30d6\u30eb\u306e\u5bfe\u8c61\u306e\u30c7\u30fc\u30bf\u3092\u524a\u9664\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n\n\n\n
\u5916\u90e8\u30ad\u30fc\u306e\u8a2d\u5b9a\u65b9\u6cd5<\/h2>\n\n\n
\u30b3\u30fc\u30c9\u3092\u7528\u3044\u3066\u5b9f\u969b\u306b\u30c6\u30fc\u30d6\u30eb\u306b\u5916\u90e8\u30ad\u30fc\u3092\u8a2d\u5b9a\u3059\u308b\u65b9\u6cd5\u3092\u89e3\u8aac\u3057\u307e\u3059\u3002
\u5916\u90e8\u30ad\u30fc\u306f\u300c\u30c6\u30fc\u30d6\u30eb\u4f5c\u6210\u6642\u306b\u8a2d\u5b9a\u3059\u308b\u65b9\u6cd5\u300d\u3068\u300c\u65e2\u6210\u30c6\u30fc\u30d6\u30eb\u306b\u5f8c\u304b\u3089\u8ffd\u52a0\u3059\u308b\u65b9\u6cd5\u300d\u306e2\u901a\u308a\u304c\u3042\u308a\u307e\u3059\u3002\u5168\u9805\u3068\u540c\u3058\u30b5\u30f3\u30d7\u30eb\u30c6\u30fc\u30d6\u30eb\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002<\/span>
<\/span><\/p>\n\n\n
\u30c6\u30fc\u30d6\u30eb\u4f5c\u6210\u6642\u306b\u8a2d\u5b9a\u3059\u308b\u65b9\u6cd5<\/h4>\n\n\n
\u65b0\u898f\u30c6\u30fc\u30d6\u30eb\u306e\u4f5c\u6210\u6642\u306b\u4e0b\u8a18\u306e\u30af\u30a8\u30ea\u3092\u8ffd\u52a0\u3059\u308b\u3053\u3068\u3067\u3001\u5916\u90e8\u30ad\u30fc\u3092\u8a2d\u5b9a\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n
FOREIGN KEY(\u53c2\u7167\u5143\u306e\u30ab\u30e9\u30e0\u540d) REFERENCES \u53c2\u7167\u5148\u306e\u30c6\u30fc\u30d6\u30eb\u540d(\u53c2\u7167\u5148\u306e\u30ab\u30e9\u30e0\u540d));<\/strong><\/code><\/pre>\n\n\n
\u3010\u4f7f\u7528\u30a4\u30e1\u30fc\u30b8\uff11\u3011<\/strong><\/p>\n\n\n
CREATE TABLE \u30c6\u30fc\u30d6\u30eb\u540d( \n \u30ab\u30e9\u30e0\u540d \u30c7\u30fc\u30bf\u578b FOREIGN KEY,\n \u30ab\u30e9\u30e0\u540d \u30c7\u30fc\u30bf\u578b,\n \u30ab\u30e9\u30e0\u540d \u30c7\u30fc\u30bf\u578b,\n \u2026\u2026\n);<\/strong><\/code><\/pre>\n\n\n
\u3010\u4f7f\u7528\u30a4\u30e1\u30fc\u30b8\uff12\u3011<\/strong><\/p>\n\n\n
CREATE TABLE \u30c6\u30fc\u30d6\u30eb\u540d( \n \u30ab\u30e9\u30e0\u540d \u30c7\u30fc\u30bf\u578b \u5c5e\u6027,\n \u30ab\u30e9\u30e0\u540d \u30c7\u30fc\u30bf\u578b \u5c5e\u6027,\n \u30ab\u30e9\u30e0\u540d \u30c7\u30fc\u30bf\u578b \u5c5e\u6027,\n \u2026\u2026\n FOREIGN KEY(\u30ab\u30e9\u30e0\u540d)\n);<\/strong><\/code><\/pre>\n\n\n\n
\u5916\u90e8\u30ad\u30fc\u3092\u5f8c\u304b\u3089\u8ffd\u52a0\u3059\u308b\u65b9\u6cd5<\/h4>\n\n\n
\u307e\u305f\u3001\u65e2\u5b58\u306e\u30c6\u30fc\u30d6\u30eb\u306b\u4e3b\u30ad\u30fc\u3092\u8a2d\u5b9a\u3059\u308b\u5834\u5408\u306f\u3001\u300cALTER TABLE\u300d\u6587\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002<\/p>\n
\u3010\u4f7f\u7528\u30a4\u30e1\u30fc\u30b8\u3011<\/strong><\/p>\n\n\n
ALTER TABLE \u30c6\u30fc\u30d6\u30eb\u540d ADD FOREIGN KEY (\u30ab\u30e9\u30e0\u540d); <\/strong><\/code><\/pre>\n\n\n\n
\u30c6\u30fc\u30d6\u30eb\u4f5c\u6210<\/h3>\n\n\n
\u30c6\u30fc\u30d6\u30eb\u4f5c\u6210\u6642\u306b\u8a2d\u5b9a\u3059\u308b\u65b9\u6cd5\u3092\u7d39\u4ecb\u3057\u307e\u3059\u3002<\/p>\n
\u307e\u305a\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u4e0a\u306b\u300c\u5f93\u696d\u54e1\u300d\u30c6\u30fc\u30d6\u30eb\u3068\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u3092\u4f5c\u6210\u3057\u307e\u3059\u3002<\/p>\n\n\n
\u89aa\u30c6\u30fc\u30d6\u30eb\u306e\u4f5c\u6210<\/h4>\n\n\n
\u3010\u5b9f\u884c\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n
CREATE TABLE department( \n id INTEGER NOT NULL PRIMARY KEY,\n dept_name VARCHAR,\n)\nENGINE=InnoDB  DEFAULT CHARSET=utf8;<\/strong><\/code><\/pre>\n\n\n\n
\u89aa\u30c6\u30fc\u30d6\u30eb\u3078\u306e\u30c7\u30fc\u30bf\u8ffd\u52a0<\/h4>\n\n\n
\u3010\u5b9f\u884c\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n
INSERT INTO department VALUES('1','\u7dcf\u52d9\u90e8');\nINSERT INTO department VALUES('2','\u4eba\u4e8b\u90e8');\nINSERT INTO department VALUES('3','\u7d4c\u7406\u90e8');\nINSERT INTO department VALUES('4','\u55b6\u696d\u90e8');\nINSERT INTO department VALUES('5','\u30de\u30fc\u30b1\u30c6\u30a3\u30f3\u30b0\u90e8');\nINSERT INTO department VALUES('6','\u60c5\u5831\u30b7\u30b9\u30c6\u30e0\u90e8\n');<\/strong><\/code><\/pre>\n\n\n\n
\u5b50\u30c6\u30fc\u30d6\u30eb\u306e\u4f5c\u6210<\/h4>\n\n\n
\u3010\u5b9f\u884c\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n
CREATE TABLE employee( \n employee_id INTEGER NOT NULL PRIMARY KEY,\n name VARCHAR,\n dept_id INTEGER,\nFOREIGN KEY(dept_id) REFERENCES department(id)\n);\nENGINE=InnoDB  DEFAULT CHARSET=utf8;<\/strong><\/code><\/pre>\n\n\n\n
\u5b50\u30c6\u30fc\u30d6\u30eb\u3078\u306e\u30c7\u30fc\u30bf\u8ffd\u52a0<\/h4>\n\n\n\n
INSERT INTO employee VALUES('0001','\u963f\u90e8','5');\nINSERT INTO employee VALUES('0002','\u83ca\u6c60','1');\nINSERT INTO employee VALUES('0003','\u9234\u6728','6');\nINSERT INTO employee VALUES('0004','\u7530\u4e2d','4');\nINSERT INTO employee VALUES('0001','\u91ce\u6751','2');\nINSERT INTO employee VALUES('0002','\u9577\u8c37\u5ddd','1');\nINSERT INTO employee VALUES('0003','\u5897\u7530','3');\nINSERT INTO employee VALUES('0004','\u6e21\u8fba','5');<\/strong><\/code><\/pre>\n\n\n
\u4ee5\u4e0a\u3067\u3001\u300c\u5f93\u696d\u54e1\u300d\u30c6\u30fc\u30d6\u30eb\u306e\u300c\u90e8\u7f72ID\u300d\u30ab\u30e9\u30e0\u306b\u5916\u90e8\u30ad\u30fc\u3092\u8a2d\u5b9a\u3067\u304d\u307e\u3057\u305f\u3002<\/p>\n\n\n
\u5916\u90e8\u30ad\u30fc\u306e\u6574\u5408\u6027\u3092\u78ba\u8a8d\u3059\u308b<\/h2>\n\n\n
\u3053\u3053\u304b\u3089\u306f\u30b3\u30fc\u30c9\u3092\u7528\u3044\u3066\u5b9f\u969b\u306b\u5916\u90e8\u30ad\u30fc\u304c\u6574\u5408\u6027\u3092\u4fdd\u8a3c\u3057\u3066\u3044\u308b\u304b\u78ba\u8a8d\u3057\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/span><\/p>\n\n\n
\u89aa\u30c6\u30fc\u30d6\u30eb\u306b\u5b58\u5728\u3057\u306a\u3044\u5024\u3092\u5b50\u30c6\u30fc\u30d6\u30eb\u306b\u767b\u9332\u3067\u304d\u306a\u3044<\/h4>\n\n\n
\u90e8\u7f72ID\u304c\u300c7\u300d\u3067\u5f93\u696d\u54e1\u3092\u767b\u9332\u3057\u3066\u307f\u307e\u3059\u3002\u4e0b\u8a18\u306e\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u78ba\u8a8d\u3067\u304d\u307e\u3059\u3002<\/p>\n
\u3010\u5b9f\u884c\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n
INSERT INTO employee VALUES('0009','\u6e21\u8fba','7');<\/strong><\/code><\/pre>\n\n\n
\u3010\u5b9f\u884c\u7d50\u679c\u3011<\/strong><\/p>\n\n\n
ERROR\u2026\u2026parent key not found<\/strong>\u2026\u2026<\/code><\/pre>\n\n\n
\u3053\u306e\u3088\u3046\u306b\u89aa\u30c6\u30fc\u30d6\u30eb\u306b\u5b58\u5728\u3057\u306a\u3044\u5024\u3092\u5b50\u30c6\u30fc\u30d6\u30eb\u306b\u767b\u9332\u3057\u3088\u3046\u3068\u3059\u308b\u3068\u30a8\u30e9\u30fc\u304c\u51fa\u307e\u3059\u3002\u306a\u304a\u3001\u66f4\u65b0\u3067\u3082\u540c\u69d8\u306b\u30a8\u30e9\u30fc\u304c\u8d77\u3053\u308a\u307e\u3059\u3002<\/p>\n\n\n
\u5b50\u30c6\u30fc\u30d6\u30eb\u306b\u767b\u9332\u3055\u308c\u3066\u3044\u308b\u5024\u3092\u89aa\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u524a\u9664\u3067\u304d\u306a\u3044<\/h4>\n\n\n
\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u306e\u300cID\u300d\u30ab\u30e9\u30e0\u306e\u300c3\u300d\u3092\u524a\u9664\u3057\u3066\u307f\u307e\u3059\u3002<\/p>\n
\u3010\u5b9f\u884c\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n
DELETE FROM department WHERE id=3;<\/strong><\/code><\/pre>\n\n\n
\u3010\u5b9f\u884c\u7d50\u679c\u3011<\/strong><\/p>\n\n\n
ERROR\u2026\u2026child record found<\/strong>\u2026\u2026<\/code><\/pre>\n\n\n
\u5916\u90e8\u30ad\u30fc\u3092\u8a2d\u5b9a\u3059\u308b\u3068\u3001\u53c2\u7167\u5148\u306e\u89aa\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u306b\u5bfe\u3057\u3066\u3082\u3001\u5bfe\u8c61\u3068\u306a\u308b\u5024\u304c\u5b50\u30c6\u30fc\u30d6\u30eb\u3067\u53c2\u7167\u3055\u308c\u3066\u3044\u308b\u5834\u5408\u3001\u524a\u9664\u30fb\u66f4\u65b0\u3067\u304d\u306a\u3044\u5236\u7d04\u304c\u8a2d\u3051\u3089\u308c\u3066\u3044\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u89aa\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u3092\u524a\u9664\u3057\u3088\u3046\u3068\u3059\u308b\u3068\u30a8\u30e9\u30fc\u306b\u306a\u3063\u3066\u524a\u9664\u3067\u304d\u307e\u305b\u3093\u3002<\/span><\/span><\/p>\n
\u5b50\u30c6\u30fc\u30d6\u30eb\u306b\u300c3\u300d\u304c\u3042\u308b\u306e\u3067\u524a\u9664\u30fb\u66f4\u65b0<\/span><\/span>\u3057\u3088\u3046\u3068\u3059\u308b\u3068\u30a8\u30e9\u30fc\u306b\u306a\u308a\u524a\u9664\u3067\u304d\u307e\u305b\u3093\u3067\u3057\u305f\u3002\u524a\u9664\u3059\u308b\u5834\u5408\u306f\u3001\u307e\u305a\u5b50\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u3092\u524a\u9664\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n
\u3053\u306e\u3088\u3046\u306b\u5916\u90e8\u30ad\u30fc\u3092\u3064\u3051\u308b\u3053\u3068\u3067\u89aa\u5b50\u9593\u306e\u6574\u5408\u6027\u304c\u4fdd\u8a3c\u3055\u308c\u307e\u3059\u3002<\/span><\/p>\n\n\n
\u89aa\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u3092\u524a\u9664\uff0f\u5909\u66f4\u3059\u308b\u65b9\u6cd5<\/h3>\n\n\n
\u30c7\u30fc\u30bf\u524a\u9664\uff1a\u5b50\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u3092\u524a\u9664\uff1e\u89aa\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u3092\u524a\u9664<\/p>\n
\u30c7\u30fc\u30bf\u5909\u66f4\uff1a\u89aa\u30c6\u30fc\u30d6\u30eb\u306b\u5909\u66f4\u5bfe\u8c61\u306e\u30c7\u30fc\u30bf\u3092\u8ffd\u52a0\uff1e\u5b50\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u3092\u5909\u66f4\uff1e\u89aa\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u3092\u524a\u9664<\/p>\n
\u5916\u90e8\u30ad\u30fc\u304c\u3064\u3044\u3066\u3044\u3066\u3082\u89aa\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u3092\u524a\u9664\u30fb\u5909\u66f4\u3057\u305f\u3044\u3068\u3044\u3063\u305f\u30b1\u30fc\u30b9\u306f\u51fa\u3066\u304d\u307e\u3059\u3002\u4e0a\u8a18\u306e\u624b\u9806\u3092\u8e0f\u3081\u3070\u3001\u30c7\u30fc\u30bf\u306e\u6574\u5408\u6027\u3092\u4fdd\u3061\u3064\u3064\u89aa\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u3092\u524a\u9664\u3057\u305f\u308a\u5909\u66f4\u3092\u52a0\u3048\u305f\u308a\u3067\u304d\u307e\u3059\u304c\u3001\u624b\u9593\u304c\u304b\u304b\u3063\u3066\u3057\u307e\u3044\u307e\u3059\u3002\u3053\u3046\u3044\u3063\u305f\u5834\u5408\u3001\u5916\u90e8\u30ad\u30fc\u3092\u8a2d\u5b9a\u3059\u308b\u969b\u306b\u300cON UPDATE CASCADE\u300d\u53e5\u3084\u300cON DELETE CASCADE\u300d\u53e5\u3092\u4ed8\u3051\u308b\u3053\u3068\u3067\u89aa\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u5909\u66f4\u6642\u3068\u524a\u9664\u6642\u306b\u8ffd\u968f\u3057\u3066\u3001<\/span>\u540c\u3058\u5024\u3092\u6301\u3064\u5b50\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u3082\u81ea\u52d5\u7684\u306b\u5909\u66f4\uff0f\u524a\u9664\u3055\u308c\u307e\u3059\u3002<\/span><\/span><\/p>\n
\u3010\u5b9f\u884c\u30a4\u30e1\u30fc\u30b8\u3011<\/strong><\/p>\n\n\n
\u2026\u2026<\/strong>\nFOREIGN KEY(\u53c2\u7167\u5143\u306e\u30ab\u30e9\u30e0\u540d) REFERENCES \u53c2\u7167\u5148\u306e\u30c6\u30fc\u30d6\u30eb\u540d(\u53c2\u7167\u5148\u306e\u30ab\u30e9\u30e0\u540d)\nON UPDATE CASCADE ON DELETE CASCADE\n);<\/strong><\/code><\/pre>\n\n\n
\u3053\u3053\u3067\u3082\u5148\u8ff0\u306e\u30b5\u30f3\u30d7\u30eb\u30c6\u30fc\u30d6\u30eb\u3092\u7528\u3044\u307e\u3059\u3002<\/p>\n
\u300c\u90e8\u7f72\uff08department\uff09\u300d\u30c6\u30fc\u30d6\u30eb<\/strong><\/p>\n\n\n
ID\uff08id\uff09<\/strong><\/td>\u90e8\u7f72\u540d\uff08dept_name\uff09<\/strong><\/td><\/tr>
1<\/td>\u7dcf\u52d9\u90e8<\/td><\/tr>
2<\/td>\u4eba\u4e8b\u90e8<\/td><\/tr>
3<\/td>\u7d4c\u7406\u90e8<\/td><\/tr>
4<\/td>\u55b6\u696d\u90e8<\/td><\/tr>
5<\/td>\u30de\u30fc\u30b1\u30c6\u30a3\u30f3\u30b0\u90e8<\/td><\/tr>
6<\/td>\u60c5\u5831\u30b7\u30b9\u30c6\u30e0\u90e8<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n
\u300c\u5f93\u696d\u54e1\uff08employee\uff09\u300d\u30c6\u30fc\u30d6\u30eb<\/strong><\/p>\n\n\n
\u5f93\u696d\u54e1ID\uff08employee_id\uff09<\/strong><\/td>\u6c0f\u540d\uff08name\uff09<\/strong><\/td>\u90e8\u7f72ID\uff08dept_id\uff09<\/strong><\/td><\/tr>
0001<\/td>\u963f\u90e8<\/td>5<\/td><\/tr>
0002<\/td>\u83ca\u6c60<\/td>1<\/td><\/tr>
0003<\/td>\u9234\u6728<\/td>6<\/td><\/tr>
0004<\/td>\u7530\u4e2d<\/td>4<\/td><\/tr>
0005<\/td>\u91ce\u6751<\/td>2<\/td><\/tr>
0006<\/td>\u9577\u8c37\u5ddd<\/td>1<\/td><\/tr>
0007<\/td>\u5897\u7530<\/td>3<\/td><\/tr>
0008<\/td>\u5c71\u7530<\/td>5<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n
\u3010\u5b9f\u884c\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n
CREATE TABLE employee( \n employee_id INTEGER NOT NULL PRIMARY KEY,\n name VARCHAR,\n dept_id INTEGER,\nFOREIGN KEY(dept_id) REFERENCES department(id)\nON UPDATE CASCADE ON DELETE CASCADE\n);\nENGINE=InnoDB  DEFAULT CHARSET=utf8;<\/strong><\/code><\/pre>\n\n\n
\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u306e\u300c\u7d4c\u7406\u90e8\u300d\u3092\u300c3\u300d\u304b\u3089\u300c7\u300d\u306b\u5909\u66f4\u3057\u307e\u3059\u3002<\/p>\n\n\n
UPDATE department SET id='3' WHERE id='7';<\/code><\/pre>\n\n\n
\u3059\u308b\u3068\u3001\u4e0b\u8a18\u306e\u3088\u3046\u306b\u300c\u5f93\u696d\u54e1\u30c6\u30fc\u30d6\u30eb\u300d\u306e\u300c\u90e8\u7f72ID\u300d\u30ab\u30e9\u30e0\u304c\u300c3\u300d\u304b\u3089\u300c7\u300d\u306b\u5909\u66f4\u3055\u308c\u3066\u3044\u308b\u306e\u304c\u308f\u304b\u308a\u307e\u3059\u3002<\/p>\n\n\n
\u5f93\u696d\u54e1ID\uff08employee_id\uff09<\/strong><\/td>\u6c0f\u540d\uff08name\uff09<\/strong><\/td>\u90e8\u7f72ID\uff08dept_id\uff09<\/strong><\/td><\/tr>
0001<\/td>\u963f\u90e8<\/td>5<\/td><\/tr>
0002<\/td>\u83ca\u6c60<\/td>1<\/td><\/tr>
0003<\/td>\u9234\u6728<\/td>6<\/td><\/tr>
0004<\/td>\u7530\u4e2d<\/td>4<\/td><\/tr>
0005<\/td>\u91ce\u6751<\/td>2<\/td><\/tr>
0006<\/td>\u9577\u8c37\u5ddd<\/td>1<\/td><\/tr>
0007<\/td>\u5897\u7530<\/td>7<\/td><\/tr>
0008<\/td>\u5c71\u7530<\/td>5<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n
\u6b21\u306b\u3001\u5148\u7a0b\u5909\u66f4\u3057\u305f\u300c\u90e8\u7f72\u300d\u30c6\u30fc\u30d6\u30eb\u306e\u300cID\u300d\u30ab\u30e9\u30e0\u300c7\u300d\u306e\u30c7\u30fc\u30bf\u3092\u524a\u9664\u3057\u307e\u3059\u3002<\/p>\n\n\n
DELETE FROM department WHERE id='7';<\/code><\/pre>\n\n\n
\u300cON DELETE CASCADE\u300d\u304c\u8a2d\u5b9a\u3055\u308c\u3066\u3044\u308b\u306e\u3067\u3001\u89aa\u30c6\u30fc\u30d6\u30eb\u3067\u524a\u9664\u3057\u305f\u30c7\u30fc\u30bf\u3068\u540c\u3058\u5024\u3092\u6301\u3064\u5b50\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u3082\u524a\u9664\u3055\u308c\u307e\u3059\u3002<\/p>\n
\u5b50\u30c6\u30fc\u30d6\u30eb\u3092\u78ba\u8a8d\u3059\u308b\u3068\u4e0b\u8a18\u306e\u3088\u3046\u306b\u300c\u5f93\u696d\u54e1\u30c6\u30fc\u30d6\u30eb\u300d\u306e\u300c\u90e8\u7f72ID\u300d\u30ab\u30e9\u30e0\u304c\u300c7\u300d\u3060\u3063\u305f\u5897\u7530\u3055\u3093\u306e\u30c7\u30fc\u30bf\u304c\u6d88\u3048\u3066\u3044\u308b\u306e\u304c\u78ba\u8a8d\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n
\u5f93\u696d\u54e1ID\uff08employee_id\uff09<\/strong><\/td>\u6c0f\u540d\uff08name\uff09<\/strong><\/td>\u90e8\u7f72ID\uff08dept_id\uff09<\/strong><\/td><\/tr>
0001<\/td>\u963f\u90e8<\/td>5<\/td><\/tr>
0002<\/td>\u83ca\u6c60<\/td>1<\/td><\/tr>
0003<\/td>\u9234\u6728<\/td>6<\/td><\/tr>
0004<\/td>\u7530\u4e2d<\/td>4<\/td><\/tr>
0005<\/td>\u91ce\u6751<\/td>2<\/td><\/tr>
0007<\/td>\u5897\u7530<\/td>6<\/td><\/tr>
0008<\/td>\u5c71\u7530<\/td>5<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n
\u203b\u30b3\u30fc\u30c9\u306b\u304a\u3051\u308b\u300cEmpty set\u300d\u306f\u691c\u7d22\u7d50\u679c\u304c0\u4ef6\u3067\u3042\u308b\u3053\u3068\u3092\u793a\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n
\u5916\u90e8\u30ad\u30fc\u5236\u7d04\u306e\u7a2e\u985e<\/h3>\n\n\n\n
ON DELETE \uff5e\uff5e\u3000\u3000\u30ec\u30b3\u30fc\u30c9\u524a\u9664\u6642\u306e\u632f\u308b\u821e\u3044\nON UPDATE \uff5e\uff5e\u3000\u3000\u30ec\u30b3\u30fc\u30c9\u66f4\u65b0\u6642\u306e\u632f\u308b\u821e\u3044<\/strong><\/code><\/pre>\n\n\n
\u5916\u90e8\u30ad\u30fc\u6307\u5b9a\u3067\u304d\u308b\u5024\u306f\u6b21\u306e\u3068\u304a\u308a\u3067\u3059\u3002\u3069\u308c\u3092\u6307\u5b9a\u3059\u308b\u304b\u3067\u53c2\u7167\u5148\u306e\u524a\u9664\u3084\u5909\u66f4\u306b\u5bfe\u3059\u308b\u632f\u308b\u821e\u3044\u304c\u5909\u308f\u308a\u3001\u5909\u66f4\u3092\u7981\u3058\u305f\u308a\u5909\u66f4\u3092\u8ffd\u968f\u3055\u305b\u305f\u308a\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n
RESTRICT<\/h4>\n\n\n
\u5b50\u30c6\u30fc\u30d6\u30eb\u3067\u767b\u9332\u3055\u308c\u3066\u3044\u308b\u5024\u3092\u3001\u89aa\u30c6\u30fc\u30d6\u30eb\u3092\u524a\u9664\u307e\u305f\u306f\u66f4\u65b0\u3057\u3088\u3046\u3068\u3059\u308b\u3068\u30a8\u30e9\u30fc\u306b\u306a\u308a\u307e\u3059\u3002\u6307\u5b9a\u3092\u7701\u7565\u3057\u305f\u5834\u5408\u3001\u30c7\u30d5\u30a9\u30eb\u30c8\u5024\u3067\u3042\u308bRESTRICT\u304c\u8a2d\u5b9a\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n
NO ACTION<\/h4>\n\n\n
RISTRICT\u540c\u69d8\u306b\u89aa\u30c6\u30fc\u30d6\u30eb\u3092\u524a\u9664\u307e\u305f\u306f\u66f4\u65b0\u3059\u308b\u3068\u30a8\u30e9\u30fc\u306b\u306a\u308a\u307e\u3059\u304c\u3001\u305d\u306e\u30c1\u30a7\u30c3\u30af\u306f\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u306e\u6700\u5f8c\u306b\u884c\u308f\u308c\u307e\u3059\u3002<\/p>\n\n\n
CASCADE<\/h4>\n\n\n
\u89aa\u30c6\u30fc\u30d6\u30eb\u3092\u524a\u9664\u307e\u305f\u306f\u66f4\u65b0\u3059\u308b\u3068\u5b50\u30c6\u30fc\u30d6\u30eb\u5185\u306e\u540c\u3058\u5024\u3092\u6301\u3064\u30ab\u30e9\u30e0\u306e\u30c7\u30fc\u30bf\u306b\u5bfe\u3057\u3066\u3082\u524a\u9664\u307e\u305f\u306f\u66f4\u65b0\u3092\u884c\u3044\u307e\u3059\u3002<\/p>\n\n\n
SET NULL<\/h4>\n\n\n
\u89aa\u30c6\u30fc\u30d6\u30eb\u3092\u524a\u9664\u307e\u305f\u306f\u66f4\u65b0\u3059\u308b\u3068\u5b50\u30c6\u30fc\u30d6\u30eb\u5185\u306e\u540c\u3058\u5024\u3092\u6301\u3064\u30ab\u30e9\u30e0\u306e\u30c7\u30fc\u30bf\u304cNULL\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n
SET DEFAULT<\/h4>\n\n\n
\u73fe\u5728\u3053\u308c\u3092\u6307\u5b9a\u3059\u308b\u3068\u30c6\u30fc\u30d6\u30eb\u306e\u4f5c\u6210\u304c\u3067\u304d\u307e\u305b\u3093\u3002<\/p>\n\n\n
\u5916\u90e8\u30ad\u30fc\u3092\u524a\u9664\u3059\u308b\u65b9\u6cd5<\/h2>\n\n\n
\u5916\u90e8\u30ad\u30fc\u3092\u524a\u9664\u3059\u308b\u306b\u306f\u3001\u300cALTER TABLE \u30c6\u30fc\u30d6\u30eb\u540d DROP FOREIGN KEY \u5916\u90e8\u30ad\u30fc\u306eID\u300d\u3067\u524a\u9664\u3067\u304d\u307e\u3059\u3002\u5916\u90e8\u30ad\u30fc\u306eID\u306f\u3001\u5916\u90e8\u30ad\u30fc\u306e\u8a2d\u5b9a\u6642\u306b\u81ea\u52d5\u3067\u6c7a\u307e\u308b\u306e\u3067\u3001\u540d\u524d\u3092\u8abf\u3079\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n
\u300cSHOW CREATE TABLE\u300d\u6587\u3067\u78ba\u8a8d\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n
\u3010\u5b9f\u884c\u30a4\u30e1\u30fc\u30b8\u3011<\/strong><\/p>\n\n\n
SHOW CREATE TABLE \u30c6\u30fc\u30d6\u30eb\u540d;<\/strong><\/code><\/pre>\n\n\n
\u4e0a\u8a18\u30af\u30a8\u30ea\u3067\u5916\u90e8\u30ad\u30fc\u306eID\u3092\u78ba\u8a8d\u3057\u305f\u3089\u5916\u90e8\u30ad\u30fc\u306e\u524a\u9664\u3092\u5b9f\u884c\u3057\u307e\u3059\u3002<\/p>\n
\u3010\u5b9f\u884c\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n
ALTER TABLE employee DROP FOREIGN KEY \u5916\u90e8\u30ad\u30fc\u306eID;<\/code><\/pre>\n\n\n
\u5916\u90e8\u30ad\u30fc\u304c\u524a\u9664\u3067\u304d\u305f\u3053\u3068\u3092\u78ba\u8a8d\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n
\n
\u3042\u306a\u305f\u306e\u3054\u5e0c\u671b\u306b\u6cbf\u3063\u305f\u6848\u4ef6\u304c\u5fc5\u305a<\/span>\u898b\u3064\u304b\u308a\u307e\u3059
\u3010\u30d5\u30ea\u30fc\u30e9\u30f3\u30b9\u5411\u3051\u3011\u9ad8\u53ce\u5165<\/span>\u30fb<\/span>\u597d\u5f85\u9047<\/span>\u306e\u6848\u4ef6\u3092\u3054\u7d39\u4ecb<\/span><\/p><\/a>\n<\/div>\n\n
\"TECH<\/a>\n<\/div>\n\n
\n
\u226b\u307e\u305a\u306f\u7c21\u535860<\/span>\u79d2\u3067\u7121\u6599\u304a\u554f\u3044\u5408\u308f\u305b<\/span>\u304b\u3089\u226a<\/p><\/a>\n<\/div>\n\n\n\n
\u5916\u90e8\u30ad\u30fc\u306e\u5f79\u5272<\/h2>\n\n\n\n
\u30c7\u30fc\u30bf\u306e\u6574\u5408\u6027\u306e\u4fdd\u6301<\/h3>\n\n\n
\u5916\u90e8\u30ad\u30fc\u3092\u8a2d\u5b9a\u3059\u308b\u3053\u3068\u3067\u3001\u89aa\u30c6\u30fc\u30d6\u30eb\u306b\u306a\u3044\u5024\u3092\u5b50\u30c6\u30fc\u30d6\u30eb\u306b\u767b\u9332\u3067\u304d\u306a\u3044\u5236\u7d04\u304c\u304b\u304b\u308b\u306e\u3067\u89aa\u5b50\u9593\u306e\u30c7\u30fc\u30bf\u306e\u6574\u5408\u6027\u304c\u4fdd\u305f\u308c\u307e\u3059\u3002<\/p>\n\n\n
\u30c7\u30fc\u30bf\u306e\u7279\u5b9a<\/h3>\n\n\n
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