{"id":162813,"date":"2024-11-04T18:13:19","date_gmt":"2024-11-04T10:13:19","guid":{"rendered":"https:\/\/server.hk\/cnblog\/162813\/"},"modified":"2024-11-04T18:13:20","modified_gmt":"2024-11-04T10:13:20","slug":"%e6%95%99%e4%bd%a0%e5%bf%ab%e9%80%9f%e6%8e%8c%e6%8f%a1db2%e6%95%b8%e6%93%9a%e5%ba%ab%e5%89%b5%e5%bb%ba%e5%a4%96%e9%8d%b5%e6%99%82%e7%9a%84%e9%81%b8%e9%a0%85","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/162813\/","title":{"rendered":"\u6559\u4f60\u5feb\u901f\u638c\u63e1DB2\u6578\u64da\u5eab\u5275\u5efa\u5916\u9375\u6642\u7684\u9078\u9805"},"content":{"rendered":"<h1 id=\"%e6%95%99%e4%bd%a0%e5%bf%ab%e9%80%9f%e6%8e%8c%e6%8f%a1db2%e6%95%b8%e6%93%9a%e5%ba%ab%e5%89%b5%e5%bb%ba%e5%a4%96%e9%8d%b5%e6%99%82%e7%9a%84%e9%81%b8%e9%a0%85-EyOHiTkdyE\">\u6559\u4f60\u5feb\u901f\u638c\u63e1DB2\u6578\u64da\u5eab\u5275\u5efa\u5916\u9375\u6642\u7684\u9078\u9805<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u8a2d\u8a08\u4e2d\uff0c\u5916\u9375\u662f\u4e00\u500b\u91cd\u8981\u7684\u6982\u5ff5\uff0c\u5b83\u7528\u65bc\u5efa\u7acb\u8868\u4e4b\u9593\u7684\u95dc\u806f\u6027\u3002DB2\u4f5c\u70baIBM\u7684\u4e00\u6b3e\u95dc\u4fc2\u578b\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u63d0\u4f9b\u4e86\u591a\u7a2e\u9078\u9805\u4f86\u5275\u5efa\u5916\u9375\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e\u5728DB2\u4e2d\u5275\u5efa\u5916\u9375\u6642\u7684\u9078\u9805\uff0c\u5e6b\u52a9\u4f60\u5feb\u901f\u638c\u63e1\u9019\u4e00\u6280\u8853\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e5%a4%96%e9%8d%b5%ef%bc%9f-EyOHiTkdyE\">\u4ec0\u9ebc\u662f\u5916\u9375\uff1f<\/h2>\n<p>\u5916\u9375\u662f\u4e00\u500b\u8868\u4e2d\u7684\u5b57\u6bb5\uff0c\u5b83\u6307\u5411\u53e6\u4e00\u500b\u8868\u7684\u4e3b\u9375\u3002\u5916\u9375\u7684\u4e3b\u8981\u4f5c\u7528\u662f\u78ba\u4fdd\u6578\u64da\u7684\u5b8c\u6574\u6027\u548c\u4e00\u81f4\u6027\u3002\u7576\u4e00\u500b\u8868\u4e2d\u7684\u67d0\u500b\u5b57\u6bb5\u88ab\u8a2d\u7f6e\u70ba\u5916\u9375\u6642\uff0cDB2\u6703\u5f37\u5236\u57f7\u884c\u53c3\u7167\u5b8c\u6574\u6027\uff0c\u9019\u610f\u5473\u8457\u5916\u9375\u5b57\u6bb5\u7684\u503c\u5fc5\u9808\u5728\u88ab\u53c3\u7167\u7684\u8868\u4e2d\u5b58\u5728\u3002<\/p>\n<h2 id=\"%e5%89%b5%e5%bb%ba%e5%a4%96%e9%8d%b5%e7%9a%84%e5%9f%ba%e6%9c%ac%e8%aa%9e%e6%b3%95-EyOHiTkdyE\">\u5275\u5efa\u5916\u9375\u7684\u57fa\u672c\u8a9e\u6cd5<\/h2>\n<p>\u5728DB2\u4e2d\uff0c\u5275\u5efa\u5916\u9375\u7684\u57fa\u672c\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>ALTER TABLE \u8868\u540d\nADD CONSTRAINT \u5916\u9375\u540d\nFOREIGN KEY (\u5916\u9375\u5b57\u6bb5)\nREFERENCES \u53c3\u7167\u8868\u540d (\u4e3b\u9375\u5b57\u6bb5);\n<\/code><\/pre>\n<p>\u9019\u6bb5\u8a9e\u6cd5\u4e2d\uff0c<code>ALTER TABLE<\/code>\u7528\u65bc\u4fee\u6539\u8868\u7d50\u69cb\uff0c<code>ADD CONSTRAINT<\/code>\u7528\u65bc\u6dfb\u52a0\u7d04\u675f\u689d\u4ef6\uff0c<code>FOREIGN KEY<\/code>\u6307\u5b9a\u5916\u9375\u5b57\u6bb5\uff0c<code>REFERENCES<\/code>\u5247\u6307\u5b9a\u4e86\u53c3\u7167\u7684\u8868\u53ca\u5176\u4e3b\u9375\u5b57\u6bb5\u3002<\/p>\n<h2 id=\"%e5%89%b5%e5%bb%ba%e5%a4%96%e9%8d%b5%e6%99%82%e7%9a%84%e9%81%b8%e9%a0%85-EyOHiTkdyE\">\u5275\u5efa\u5916\u9375\u6642\u7684\u9078\u9805<\/h2>\n<p>\u5728\u5275\u5efa\u5916\u9375\u6642\uff0cDB2\u63d0\u4f9b\u4e86\u5e7e\u500b\u9078\u9805\u4f86\u63a7\u5236\u5916\u9375\u7684\u884c\u70ba\uff1a<\/p>\n<ul>\n<li><strong>ON DELETE CASCADE<\/strong>: \u7576\u53c3\u7167\u8868\u4e2d\u7684\u884c\u88ab\u522a\u9664\u6642\uff0c\u6240\u6709\u5f15\u7528\u8a72\u884c\u7684\u5916\u9375\u884c\u4e5f\u6703\u88ab\u81ea\u52d5\u522a\u9664\u3002<\/li>\n<li><strong>ON DELETE SET NULL<\/strong>: \u7576\u53c3\u7167\u8868\u4e2d\u7684\u884c\u88ab\u522a\u9664\u6642\uff0c\u6240\u6709\u5f15\u7528\u8a72\u884c\u7684\u5916\u9375\u884c\u7684\u5916\u9375\u5b57\u6bb5\u5c07\u88ab\u8a2d\u7f6e\u70baNULL\u3002<\/li>\n<li><strong>ON UPDATE CASCADE<\/strong>: \u7576\u53c3\u7167\u8868\u4e2d\u7684\u4e3b\u9375\u503c\u88ab\u66f4\u65b0\u6642\uff0c\u6240\u6709\u5f15\u7528\u8a72\u4e3b\u9375\u7684\u5916\u9375\u884c\u4e5f\u6703\u81ea\u52d5\u66f4\u65b0\u3002<\/li>\n<li><strong>ON UPDATE SET NULL<\/strong>: \u7576\u53c3\u7167\u8868\u4e2d\u7684\u4e3b\u9375\u503c\u88ab\u66f4\u65b0\u6642\uff0c\u6240\u6709\u5f15\u7528\u8a72\u4e3b\u9375\u7684\u5916\u9375\u884c\u7684\u5916\u9375\u5b57\u6bb5\u5c07\u88ab\u8a2d\u7f6e\u70baNULL\u3002<\/li>\n<\/ul>\n<h3 id=\"%e7%a4%ba%e4%be%8b-EyOHiTkdyE\">\u793a\u4f8b<\/h3>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u5275\u5efa\u5916\u9375\u7684\u793a\u4f8b\uff0c\u5047\u8a2d\u6211\u5011\u6709\u5169\u500b\u8868\uff1a<code>orders<\/code>\u548c<code>customers<\/code>\uff0c\u5176\u4e2d<code>orders<\/code>\u8868\u4e2d\u7684<code>customer_id<\/code>\u5b57\u6bb5\u662f\u5916\u9375\uff0c\u53c3\u7167<code>customers<\/code>\u8868\u4e2d\u7684<code>id<\/code>\u5b57\u6bb5\u3002<\/p>\n<pre><code>ALTER TABLE orders\nADD CONSTRAINT fk_customer\nFOREIGN KEY (customer_id)\nREFERENCES customers (id)\nON DELETE CASCADE\nON UPDATE CASCADE;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u793a\u4f8b\u4e2d\uff0c\u7576<code>customers<\/code>\u8868\u4e2d\u7684\u67d0\u500b\u5ba2\u6236\u88ab\u522a\u9664\u6642\uff0c\u6240\u6709\u8207\u8a72\u5ba2\u6236\u76f8\u95dc\u7684\u8a02\u55ae\u4e5f\u6703\u88ab\u81ea\u52d5\u522a\u9664\u3002\u540c\u6a23\uff0c\u5982\u679c\u5ba2\u6236\u7684ID\u88ab\u66f4\u65b0\uff0c\u6240\u6709\u76f8\u95dc\u7684\u8a02\u55ae\u4e2d\u7684<code>customer_id<\/code>\u4e5f\u6703\u96a8\u4e4b\u66f4\u65b0\u3002<\/p>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-EyOHiTkdyE\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u5728\u5275\u5efa\u5916\u9375\u6642\uff0c\u6709\u5e7e\u500b\u6ce8\u610f\u4e8b\u9805\u9700\u8981\u8003\u616e\uff1a<\/p>\n<ul>\n<li>\u5916\u9375\u5b57\u6bb5\u7684\u6578\u64da\u985e\u578b\u5fc5\u9808\u8207\u53c3\u7167\u8868\u7684\u4e3b\u9375\u5b57\u6bb5\u76f8\u540c\u3002<\/li>\n<li>\u5728\u5275\u5efa\u5916\u9375\u4e4b\u524d\uff0c\u78ba\u4fdd\u53c3\u7167\u7684\u8868\u5df2\u7d93\u5b58\u5728\u3002<\/li>\n<li>\u8003\u616e\u5230\u6027\u80fd\u554f\u984c\uff0c\u61c9\u8b39\u614e\u4f7f\u7528<code>ON DELETE CASCADE<\/code>\u548c<code>ON UPDATE CASCADE<\/code>\uff0c\u7279\u5225\u662f\u5728\u5927\u578b\u6578\u64da\u96c6\u4e0a\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-EyOHiTkdyE\">\u7e3d\u7d50<\/h2>\n<p>\u638c\u63e1DB2\u4e2d\u5275\u5efa\u5916\u9375\u7684\u9078\u9805\u5c0d\u65bc\u6578\u64da\u5eab\u8a2d\u8a08\u81f3\u95dc\u91cd\u8981\u3002\u901a\u904e\u5408\u7406\u4f7f\u7528\u5916\u9375\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u7dad\u8b77\u6578\u64da\u7684\u5b8c\u6574\u6027\u548c\u4e00\u81f4\u6027\u3002\u5e0c\u671b\u672c\u6587\u80fd\u5e6b\u52a9\u4f60\u66f4\u597d\u5730\u7406\u89e3DB2\u6578\u64da\u5eab\u4e2d\u7684\u5916\u9375\u5275\u5efa\u904e\u7a0b\u3002\u5982\u679c\u4f60\u9700\u8981\u66f4\u591a\u7684\u6280\u8853\u652f\u6301\u6216\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u4e86\u89e3\u66f4\u591a\u4fe1\u606f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5feb\u901f\u638c\u63e1DB2\u6578\u64da\u5eab\u5275\u5efa\u5916\u9375\u7684\u9078\u9805\uff0c\u63d0\u5347\u6578\u64da\u5b8c\u6574\u6027\u8207\u95dc\u806f\u6027\uff0c\u7c21\u5316\u6578\u64da\u7ba1\u7406\u6d41\u7a0b\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-162813","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/162813","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=162813"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/162813\/revisions"}],"predecessor-version":[{"id":162814,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/162813\/revisions\/162814"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=162813"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=162813"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=162813"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}