{"id":95946,"date":"2024-10-20T05:19:17","date_gmt":"2024-10-19T21:19:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/95946\/"},"modified":"2024-10-20T05:19:17","modified_gmt":"2024-10-19T21:19:17","slug":"oracle%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%adconstraint%e7%b4%84%e6%9d%9f%e7%9a%84%e5%9b%9b%e5%b0%8d%e5%b1%ac%e6%80%a7","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/95946\/","title":{"rendered":"Oracle\u6578\u64da\u5eab\u4e2dConstraint\u7d04\u675f\u7684\u56db\u5c0d\u5c6c\u6027"},"content":{"rendered":"

Oracle\u6578\u64da\u5eab\u4e2dConstraint\u7d04\u675f\u7684\u56db\u5c0d\u5c6c\u6027<\/h1>\n

\u5728Oracle\u6578\u64da\u5eab\u4e2d\uff0cConstraint\uff08\u7d04\u675f\uff09\u662f\u7528\u4f86\u9650\u5236\u6578\u64da\u8868\u4e2d\u6578\u64da\u7684\u6709\u6548\u6027\u548c\u5b8c\u6574\u6027\u7684\u91cd\u8981\u5de5\u5177\u3002\u7d04\u675f\u53ef\u4ee5\u78ba\u4fdd\u6578\u64da\u7684\u6e96\u78ba\u6027\uff0c\u9632\u6b62\u4e0d\u5408\u898f\u7684\u6578\u64da\u9032\u5165\u6578\u64da\u5eab\u3002\u672c\u6587\u5c07\u63a2\u8a0eOracle\u6578\u64da\u5eab\u4e2dConstraint\u7d04\u675f\u7684\u56db\u5c0d\u5c6c\u6027\uff0c\u5e6b\u52a9\u8b80\u8005\u66f4\u597d\u5730\u7406\u89e3\u5176\u529f\u80fd\u548c\u61c9\u7528\u3002<\/p>\n

1. \u552f\u4e00\u6027\u7d04\u675f\uff08UNIQUE\uff09<\/h2>\n

\u552f\u4e00\u6027\u7d04\u675f\u78ba\u4fdd\u6578\u64da\u8868\u4e2d\u7684\u67d0\u4e00\u5217\u6216\u591a\u5217\u7684\u503c\u662f\u552f\u4e00\u7684\uff0c\u9019\u610f\u5473\u8457\u4e0d\u5141\u8a31\u6709\u91cd\u8907\u7684\u6578\u64da\u3002\u9019\u5c0d\u65bc\u9700\u8981\u552f\u4e00\u6a19\u8b58\u7684\u6578\u64da\u975e\u5e38\u91cd\u8981\uff0c\u4f8b\u5982\u7528\u6236\u540d\u6216\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u3002<\/p>\n

CREATE TABLE users (\n    user_id NUMBER PRIMARY KEY,\n    username VARCHAR2(50) UNIQUE,\n    email VARCHAR2(100) UNIQUE\n);<\/code><\/pre>\n
\u5728\u4e0a\u8ff0\u793a\u4f8b\u4e2d\uff0cusername\u548cemail\u5217\u90fd\u8a2d\u7f6e\u4e86\u552f\u4e00\u6027\u7d04\u675f\uff0c\u9019\u6a23\u53ef\u4ee5\u9632\u6b62\u5169\u500b\u7528\u6236\u64c1\u6709\u76f8\u540c\u7684\u7528\u6236\u540d\u6216\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u3002<\/p>\n
2. \u4e3b\u9375\u7d04\u675f\uff08PRIMARY KEY\uff09<\/h2>\n
\u4e3b\u9375\u7d04\u675f\u662f\u4e00\u7a2e\u7279\u6b8a\u7684\u552f\u4e00\u6027\u7d04\u675f\uff0c\u5b83\u4e0d\u50c5\u8981\u6c42\u5217\u4e2d\u7684\u503c\u552f\u4e00\uff0c\u9084\u4e0d\u5141\u8a31\u6709\u7a7a\u503c\uff08NULL\uff09\u3002\u4e3b\u9375\u901a\u5e38\u7528\u65bc\u552f\u4e00\u6a19\u8b58\u6578\u64da\u8868\u4e2d\u7684\u6bcf\u4e00\u884c\u3002<\/p>\n
CREATE TABLE products (\n    product_id NUMBER PRIMARY KEY,\n    product_name VARCHAR2(100) NOT NULL\n);<\/code><\/pre>\n
\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0cproduct_id\u5217\u88ab\u8a2d\u7f6e\u70ba\u4e3b\u9375\uff0c\u9019\u610f\u5473\u8457\u6bcf\u500b\u7522\u54c1\u90fd\u5fc5\u9808\u6709\u4e00\u500b\u552f\u4e00\u7684ID\uff0c\u4e26\u4e14\u9019\u500bID\u4e0d\u80fd\u70baNULL\u3002<\/p>\n
3. \u5916\u9375\u7d04\u675f\uff08FOREIGN KEY\uff09<\/h2>\n
\u5916\u9375\u7d04\u675f\u7528\u65bc\u5efa\u7acb\u5169\u500b\u8868\u4e4b\u9593\u7684\u95dc\u806f\u3002\u5b83\u78ba\u4fdd\u4e00\u500b\u8868\u4e2d\u7684\u67d0\u4e00\u5217\u7684\u503c\u5fc5\u9808\u5728\u53e6\u4e00\u500b\u8868\u7684\u4e3b\u9375\u5217\u4e2d\u5b58\u5728\u3002\u9019\u6709\u52a9\u65bc\u7dad\u8b77\u6578\u64da\u7684\u53c3\u7167\u5b8c\u6574\u6027\u3002<\/p>\n
CREATE TABLE orders (\n    order_id NUMBER PRIMARY KEY,\n    user_id NUMBER,\n    FOREIGN KEY (user_id) REFERENCES users(user_id)\n);<\/code><\/pre>\n
\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0corders\u8868\u4e2d\u7684user_id\u5217\u662f\u5916\u9375\uff0c\u6307\u5411users\u8868\u4e2d\u7684user_id\u5217\u3002\u9019\u610f\u5473\u8457\u6bcf\u500b\u8a02\u55ae\u90fd\u5fc5\u9808\u8207\u4e00\u500b\u6709\u6548\u7684\u7528\u6236\u76f8\u95dc\u806f\u3002<\/p>\n
4. \u6aa2\u67e5\u7d04\u675f\uff08CHECK\uff09<\/h2>\n
\u6aa2\u67e5\u7d04\u675f\u7528\u65bc\u9650\u5236\u5217\u4e2d\u7684\u503c\uff0c\u78ba\u4fdd\u5b83\u5011\u7b26\u5408\u7279\u5b9a\u7684\u689d\u4ef6\u3002\u9019\u53ef\u4ee5\u7528\u4f86\u5f37\u5236\u57f7\u884c\u696d\u52d9\u898f\u5247\uff0c\u4f8b\u5982\u5e74\u9f61\u5fc5\u9808\u5927\u65bc18\u6b72\u3002<\/p>\n
CREATE TABLE employees (\n    employee_id NUMBER PRIMARY KEY,\n    age NUMBER CHECK (age > 18)\n);<\/code><\/pre>\n
\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0cage\u5217\u8a2d\u7f6e\u4e86\u6aa2\u67e5\u7d04\u675f\uff0c\u78ba\u4fdd\u6240\u6709\u54e1\u5de5\u7684\u5e74\u9f61\u90fd\u5fc5\u9808\u5927\u65bc18\u6b72\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
Oracle\u6578\u64da\u5eab\u4e2d\u7684Constraint\u7d04\u675f\u662f\u78ba\u4fdd\u6578\u64da\u5b8c\u6574\u6027\u548c\u6e96\u78ba\u6027\u7684\u95dc\u9375\u5de5\u5177\u3002\u901a\u904e\u4f7f\u7528\u552f\u4e00\u6027\u7d04\u675f\u3001\u4e3b\u9375\u7d04\u675f\u3001\u5916\u9375\u7d04\u675f\u548c\u6aa2\u67e5\u7d04\u675f\uff0c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u53ef\u4ee5\u6709\u6548\u5730\u7ba1\u7406\u6578\u64da\uff0c\u9632\u6b62\u4e0d\u5408\u898f\u7684\u6578\u64da\u9032\u5165\u7cfb\u7d71\u3002\u4e86\u89e3\u9019\u4e9b\u7d04\u675f\u7684\u5c6c\u6027\u548c\u61c9\u7528\uff0c\u5c0d\u65bc\u8a2d\u8a08\u548c\u7dad\u8b77\u9ad8\u6548\u7684\u6578\u64da\u5eab\u7cfb\u7d71\u81f3\u95dc\u91cd\u8981\u3002<\/p>\n
\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f\u6578\u64da\u5eab\u7ba1\u7406\u9084\u662f\u5176\u4ed6\u61c9\u7528\uff0c\u6211\u5011\u7684 \u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u4e86\u89e3Oracle\u6578\u64da\u5eab\u4e2dConstraint\u7d04\u675f\u7684\u56db\u5c0d\u5c6c\u6027\uff0c\u5305\u62ec\u4e3b\u9375\u3001\u5916\u9375\u3001\u552f\u4e00\u6027\u548c\u6aa2\u67e5\u7d04\u675f\uff0c\u78ba\u4fdd\u6578\u64da\u5b8c\u6574\u6027\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-95946","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95946","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=95946"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95946\/revisions"}],"predecessor-version":[{"id":95947,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95946\/revisions\/95947"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=95946"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=95946"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=95946"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}