{"id":5874,"date":"2024-11-14T14:09:06","date_gmt":"2024-11-14T06:09:06","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5874\/"},"modified":"2024-11-14T14:09:06","modified_gmt":"2024-11-14T06:09:06","slug":"sql%e5%a4%96%e9%94%ae%e7%ba%a6%e6%9d%9f%e6%80%8e%e4%b9%88%e5%88%9b%e5%bb%ba","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5874\/","title":{"rendered":"sql\u5916\u952e\u7ea6\u675f\u600e\u4e48\u521b\u5efa"},"content":{"rendered":"<blockquote><p>\n  \u5982\u4f55\u521b\u5efa sql \u5916\u952e\u7ea6\u675f\uff1f\u6b65\u9aa4\uff1a\u4f7f\u7528 foreign key \u5b50\u53e5\u5b9a\u4e49\u5916\u952e\u7ea6\u675f\u3002\u6307\u5b9a\u5b50\u8868\u4e2d\u7684\u5f15\u7528\u5217\u548c\u7236\u8868\u4e2d\u7684\u88ab\u5f15\u7528\u5217\u3002\u53ef\u9009\uff1a\u6dfb\u52a0\u7ea6\u675f\u9009\u9879\uff0c\u4f8b\u5982\u7ea7\u8054\u64cd\u4f5c\u6216\u5ef6\u8fdf\u68c0\u67e5\u3002\u5916\u952e\u7ea6\u675f\u5fc5\u987b\u5f15\u7528\u7236\u8868\u7684\u4e3b\u952e\u6216\u552f\u4e00\u952e\u3002\n<\/p><\/blockquote>\n<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/202406\/03\/2024060321245686049.jpg\" class=\"aligncenter\" title=\"sql\u5916\u952e\u7ea6\u675f\u600e\u4e48\u521b\u5efa\u63d2\u56fe\" alt=\"sql\u5916\u952e\u7ea6\u675f\u600e\u4e48\u521b\u5efa\u63d2\u56fe\" \/><\/p>\n<p><strong>\u5982\u4f55\u521b\u5efa SQL \u5916\u952e\u7ea6\u675f<\/strong><\/p>\n<p>\u5916\u952e\u7ea6\u675f\u5728 SQL \u4e2d\u7528\u4e8e\u786e\u4fdd\u6570\u636e\u5b8c\u6574\u6027\uff0c\u901a\u8fc7\u5efa\u7acb\u4e24\u4e2a\u8868\u4e4b\u95f4\u7684\u5173\u7cfb\uff0c\u5f3a\u5236\u8981\u6c42\u5b50\u8868\u4e2d\u7684\u503c\u5f15\u7528\u7236\u8868\u4e2d\u7684\u76f8\u5e94\u503c\u3002\u521b\u5efa\u5916\u952e\u7ea6\u675f\u7684\u6b65\u9aa4\u5982\u4e0b\uff1a<\/p>\n<p><strong>1. \u5b9a\u4e49\u5916\u952e\u7ea6\u675f<\/strong><\/p>\n<p>\u4f7f\u7528 FOREIGN KEY \u5b50\u53e5\u5b9a\u4e49\u5916\u952e\u7ea6\u675f\u3002\u8be5\u5b50\u53e5\u5305\u542b\u4ee5\u4e0b\u5185\u5bb9\uff1a<\/p>\n<ul>\n<li> <strong>\u5b50\u8868\u4e2d\u7684\u5f15\u7528\u5217\uff1a<\/strong>\u5f15\u7528\u7236\u8868\u4e2d\u5217\u7684\u5b50\u8868\u4e2d\u7684\u5217\u3002<\/li>\n<li> <strong>REFERENCES \u5b50\u53e5\uff1a<\/strong>\u6307\u5b9a\u5f15\u7528\u7236\u8868\u3002<\/li>\n<li> <strong>\u7236\u8868\u4e2d\u7684\u88ab\u5f15\u7528\u5217\uff1a<\/strong>\u7236\u8868\u4e2d\u7684\u5217\uff0c\u5176\u503c\u7531\u5b50\u8868\u4e2d\u7684\u5f15\u7528\u5217\u5f15\u7528\u3002<\/li>\n<\/ul>\n<p>\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre>ALTER TABLE \u5b50\u8868\nADD FOREIGN KEY (\u5f15\u7528\u5217)\nREFERENCES \u7236\u8868 (\u88ab\u5f15\u7528\u5217)<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p><strong>2. \u4f8b\u5b50<\/strong><\/p>\n<p>\u4f8b\u5982\uff0c\u8981\u4e3a \u8ba2\u5355 \u8868\u4e2d\u7684 \u5ba2\u6237 ID \u5217\u521b\u5efa\u5916\u952e\u7ea6\u675f\uff0c\u4f7f\u5176\u5f15\u7528 \u5ba2\u6237 \u8868\u4e2d\u7684 \u5ba2\u6237 ID \u5217\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8bed\u53e5\uff1a<\/p>\n<pre>ALTER TABLE \u8ba2\u5355\nADD FOREIGN KEY (\u5ba2\u6237 ID)\nREFERENCES \u5ba2\u6237 (\u5ba2\u6237 ID)<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p><strong>3. \u7ea6\u675f\u9009\u9879\uff08\u53ef\u9009\uff09<\/strong><\/p>\n<p>\u5916\u952e\u7ea6\u675f\u53ef\u4ee5\u5305\u542b\u4ee5\u4e0b\u53ef\u9009\u9009\u9879\uff1a<\/p>\n<ul>\n<li> <strong>ON DELETE \u548c ON UPDATE \u52a8\u4f5c\uff1a<\/strong>\u6307\u5b9a\u5f53\u7236\u8868\u4e2d\u7684\u6570\u636e\u53d1\u751f\u66f4\u6539\u65f6\u5bf9\u5b50\u8868\u8bb0\u5f55\u6267\u884c\u7684\u64cd\u4f5c\uff08\u4f8b\u5982 CASCADE\u3001SET NULL \u6216 SET DEFAULT\uff09\u3002<\/li>\n<li> <strong>DEFERRABLE \u548c NOT DEFERRABLE\uff1a<\/strong>\u6307\u5b9a\u662f\u5426\u5141\u8bb8\u5728 DML \u64cd\u4f5c\u4e2d\u5ef6\u8fdf\u68c0\u67e5\u5916\u952e\u7ea6\u675f\u3002<\/li>\n<li> <strong>MATCH \u7c7b\u578b\uff1a<\/strong>\u6307\u5b9a\u5916\u952e\u5f15\u7528\u5217\u548c\u88ab\u5f15\u7528\u5217\u4e4b\u95f4\u7684\u5339\u914d\u7c7b\u578b\uff08\u4f8b\u5982 FULL\u3001PARTIAL \u6216 SIMPLE\uff09\u3002<\/li>\n<\/ul>\n<p><strong>4. \u6ce8\u610f\u70b9<\/strong><\/p>\n<ul>\n<li>\u5916\u952e\u7ea6\u675f\u5fc5\u987b\u5f15\u7528\u7236\u8868\u4e2d\u7684\u4e3b\u952e\u6216\u552f\u4e00\u952e\u3002<\/li>\n<li>\u5982\u679c\u7236\u8868\u4e2d\u7684\u6570\u636e\u53d1\u751f\u66f4\u6539\uff0c\u53ef\u80fd\u4f1a\u89e6\u53d1\u5b50\u8868\u4e2d\u7684\u7ea7\u8054\u64cd\u4f5c\u3002<\/li>\n<li>\u5916\u952e\u7ea6\u675f\u53ef\u4ee5\u5f71\u54cd\u63d2\u5165\u3001\u66f4\u65b0\u548c\u5220\u9664\u64cd\u4f5c\u7684\u6027\u80fd\u3002<\/li>\n<\/ul>\n<p>\u4ee5\u4e0a\u5c31\u662fsql\u5916\u952e\u7ea6\u675f\u600e\u4e48\u521b\u5efa\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u7f51\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5982\u4f55\u521b\u5efa sql \u5916\u952e\u7ea6\u675f\uff1f\u6b65\u9aa4\uff1a\u4f7f\u7528 foreign key \u5b50\u53e5\u5b9a\u4e49\u5916\u952e\u7ea6\u675f\u3002\u6307\u5b9a\u5b50\u8868\u4e2d\u7684\u5f15\u7528\u5217\u548c\u7236\u8868\u4e2d\u7684\u88ab\u5f15\u7528\u5217\u3002\u53ef\u9009\uff1a\u6dfb\u52a0\u7ea6\u675f\u9009\u9879\uff0c\u4f8b\u5982\u7ea7\u8054\u64cd\u4f5c\u6216\u5ef6\u8fdf\u68c0\u67e5\u3002\u5916\u952e\u7ea6\u675f\u5fc5\u987b\u5f15\u7528\u7236\u8868\u7684\u4e3b\u952e\u6216\u552f\u4e00\u952e\u3002 \u5982\u4f55\u521b\u5efa SQL \u5916\u952e\u7ea6\u675f \u5916\u952e\u7ea6\u675f\u5728 SQL \u4e2d\u7528\u4e8e\u786e\u4fdd\u6570\u636e\u5b8c\u6574\u6027\uff0c\u901a\u8fc7\u5efa\u7acb\u4e24\u4e2a\u8868\u4e4b\u95f4\u7684\u5173\u7cfb\uff0c\u5f3a\u5236\u8981\u6c42\u5b50\u8868\u4e2d\u7684\u503c\u5f15\u7528\u7236\u8868\u4e2d\u7684\u76f8\u5e94\u503c\u3002\u521b\u5efa\u5916\u952e\u7ea6\u675f\u7684\u6b65\u9aa4\u5982\u4e0b\uff1a 1. \u5b9a\u4e49\u5916\u952e\u7ea6\u675f \u4f7f\u7528 FOREIGN KEY \u5b50\u53e5\u5b9a\u4e49\u5916\u952e\u7ea6\u675f\u3002\u8be5\u5b50\u53e5\u5305\u542b\u4ee5\u4e0b\u5185\u5bb9\uff1a \u5b50\u8868\u4e2d\u7684\u5f15\u7528\u5217\uff1a\u5f15\u7528\u7236\u8868\u4e2d\u5217\u7684\u5b50\u8868\u4e2d\u7684\u5217\u3002 REFERENCES \u5b50\u53e5\uff1a\u6307\u5b9a\u5f15\u7528\u7236\u8868\u3002 \u7236\u8868\u4e2d\u7684\u88ab\u5f15\u7528\u5217\uff1a\u7236\u8868\u4e2d\u7684\u5217\uff0c\u5176\u503c\u7531\u5b50\u8868\u4e2d\u7684\u5f15\u7528\u5217\u5f15\u7528\u3002 \u8bed\u6cd5\u5982\u4e0b\uff1a ALTER TABLE \u5b50\u8868 ADD FOREIGN KEY (\u5f15\u7528\u5217) REFERENCES \u7236\u8868 (\u88ab\u5f15\u7528\u5217) \u767b\u5f55\u540e\u590d\u5236 2. \u4f8b\u5b50 \u4f8b\u5982\uff0c\u8981\u4e3a \u8ba2\u5355 \u8868\u4e2d\u7684 \u5ba2\u6237 ID \u5217\u521b\u5efa\u5916\u952e\u7ea6\u675f\uff0c\u4f7f\u5176\u5f15\u7528 \u5ba2\u6237 \u8868\u4e2d\u7684 \u5ba2\u6237 ID \u5217\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8bed\u53e5\uff1a ALTER TABLE \u8ba2\u5355 ADD FOREIGN KEY (\u5ba2\u6237 ID) [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-5874","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5874","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=5874"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5874\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5874"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5874"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5874"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}