{"id":794,"date":"2025-01-09T00:34:14","date_gmt":"2025-01-08T16:34:14","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=794"},"modified":"2025-01-09T00:34:14","modified_gmt":"2025-01-08T16:34:14","slug":"sql%e9%81%87%e5%88%b0%e6%97%a0%e6%b3%95%e5%88%a0%e9%99%a4%e5%af%b9%e8%b1%a1%ef%bc%8c%e5%9b%a0%e4%b8%ba%e8%af%a5%e5%af%b9%e8%b1%a1%e6%ad%a3%e7%94%b1%e4%b8%80%e4%b8%aa-foreign-key-%e7%ba%a6","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/01\/09\/sql%e9%81%87%e5%88%b0%e6%97%a0%e6%b3%95%e5%88%a0%e9%99%a4%e5%af%b9%e8%b1%a1%ef%bc%8c%e5%9b%a0%e4%b8%ba%e8%af%a5%e5%af%b9%e8%b1%a1%e6%ad%a3%e7%94%b1%e4%b8%80%e4%b8%aa-foreign-key-%e7%ba%a6\/","title":{"rendered":"SQL\u9047\u5230\u201c\u65e0\u6cd5\u5220\u9664\u5bf9\u8c61*\uff0c\u56e0\u4e3a\u8be5\u5bf9\u8c61\u6b63\u7531\u4e00\u4e2a FOREIGN KEY \u7ea6\u675f\u5f15\u7528\u201d\u9519\u8bef\u65f6\u600e\u4e48\u529e\uff1f"},"content":{"rendered":"\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u5728 SQL \u4e2d\uff0c\u5f53\u4f60\u9047\u5230 <strong>\u201c\u65e0\u6cd5\u5220\u9664\u5bf9\u8c61<\/strong><em>\uff0c\u56e0\u4e3a\u8be5\u5bf9\u8c61\u6b63\u7531\u4e00\u4e2a FOREIGN KEY \u7ea6\u675f\u5f15\u7528\u201d<\/em>* \u7684\u9519\u8bef\u65f6\uff0c\u901a\u5e38\u662f\u56e0\u4e3a\u8be5\u8868\uff08\u6216\u5bf9\u8c61\uff09\u6b63\u5728\u88ab\u5176\u4ed6\u8868\u901a\u8fc7\u5916\u952e\uff08<code>FOREIGN KEY<\/code>\uff09\u5f15\u7528\u3002\u8fd9\u610f\u5473\u7740\u5728\u5c1d\u8bd5\u5220\u9664\u7684\u8868\u6216\u5bf9\u8c61\u4e0a\uff0c\u6709\u4e00\u4e2a\u6216\u591a\u4e2a\u5916\u952e\u7ea6\u675f\u4f9d\u8d56\u4e8e\u5b83\uff0c\u4ece\u800c\u963b\u6b62\u4e86\u5220\u9664\u64cd\u4f5c\u3002<\/p>\n<\/blockquote>\n\n\n\n<h3 class=\"wp-block-heading\">\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u7684\u65b9\u6cd5\u5982\u4e0b\uff1a<\/h3>\n\n\n\n<h3 class=\"wp-block-heading\">1. <strong>\u5220\u9664\u6216\u4fee\u6539\u5916\u952e\u7ea6\u675f<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f60\u9700\u8981\u5148\u5220\u9664\u6216\u7981\u7528\u5f15\u7528\u8be5\u5bf9\u8c61\u7684\u5916\u952e\u7ea6\u675f\uff0c\u7136\u540e\u518d\u6267\u884c\u5220\u9664\u64cd\u4f5c\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">#### \u6b65\u9aa4\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u67e5\u770b\u5916\u952e\u7ea6\u675f<\/strong>\n<ul class=\"wp-block-list\">\n<li>\u4f7f\u7528\u4ee5\u4e0b SQL \u547d\u4ee4\u67e5\u770b\u8868\u4e2d\u6240\u6709\u7684\u5916\u952e\u7ea6\u675f\uff1a <code>SHOW CREATE TABLE `\u8868\u540d`;<\/code> \u8fd9\u5c06\u663e\u793a\u8868\u7684\u521b\u5efa\u8bed\u53e5\uff0c\u5176\u4e2d\u5305\u542b\u5916\u952e\u7ea6\u675f\u7684\u4fe1\u606f\uff0c\u5e2e\u52a9\u4f60\u627e\u5230\u54ea\u4e9b\u8868\u6216\u5217\u5f15\u7528\u4e86\u5f53\u524d\u8868\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u5220\u9664\u5916\u952e\u7ea6\u675f<\/strong>\n<ul class=\"wp-block-list\">\n<li>\u627e\u5230\u5916\u952e\u7ea6\u675f\u7684\u540d\u79f0\u540e\uff0c\u53ef\u4ee5\u4f7f\u7528 <code>ALTER TABLE<\/code> \u547d\u4ee4\u5220\u9664\u5916\u952e\u7ea6\u675f\u3002\u4f8b\u5982\uff0c\u5047\u8bbe\u5916\u952e\u7ea6\u675f\u7684\u540d\u79f0\u662f <code>fk_example<\/code>\uff0c\u4f60\u53ef\u4ee5\u6267\u884c\u4ee5\u4e0b\u547d\u4ee4\uff1a <code>ALTER TABLE `\u5f15\u7528\u8868\u540d` DROP FOREIGN KEY `fk_example`;<\/code><\/li>\n\n\n\n<li>\u6ce8\u610f\uff1a<code>\u5f15\u7528\u8868\u540d<\/code> \u662f\u5916\u952e\u7ea6\u675f\u6240\u5728\u7684\u8868\u540d\uff0c<code>fk_example<\/code> \u662f\u5916\u952e\u7ea6\u675f\u7684\u540d\u79f0\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u5220\u9664\u6216\u4fee\u6539\u6570\u636e<\/strong>\n<ul class=\"wp-block-list\">\n<li>\u5220\u9664\u5916\u952e\u7ea6\u675f\u540e\uff0c\u60a8\u53ef\u4ee5\u7ee7\u7eed\u5220\u9664\u539f\u5bf9\u8c61\u3002\u5982\u679c\u4f60\u4e0d\u60f3\u5220\u9664\u5916\u952e\u7ea6\u675f\uff0c\u53ef\u4ee5\u9009\u62e9\u5220\u9664\u6216\u4fee\u6539\u5916\u952e\u8868\u4e2d\u4e0e\u4e4b\u76f8\u5173\u8054\u7684\u6570\u636e\u3002 <code>DELETE FROM `\u5f15\u7528\u8868\u540d` WHERE `\u5916\u952e\u5b57\u6bb5` = '\u76f8\u5e94\u503c';<\/code><\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">2. <strong>\u4fee\u6539\u5916\u952e\u7ea6\u675f\u884c\u4e3a\uff08\u8bbe\u7f6e\u7ea7\u8054\u5220\u9664\uff09<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u4f60\u4e0d\u5e0c\u671b\u6bcf\u6b21\u5220\u9664\u8868\u65f6\u624b\u52a8\u5220\u9664\u5916\u952e\u7ea6\u675f\uff0c\u53ef\u4ee5\u8003\u8651\u4fee\u6539\u5916\u952e\u7ea6\u675f\uff0c\u4ee5\u4fbf\u5728\u5220\u9664\u4e3b\u8868\u8bb0\u5f55\u65f6\u81ea\u52a8\u5220\u9664\u6216\u66f4\u65b0\u76f8\u5173\u8868\u4e2d\u7684\u8bb0\u5f55\u3002\u8fd9\u53ef\u4ee5\u901a\u8fc7\u8bbe\u7f6e\u5916\u952e\u7ea6\u675f\u7684 <strong>ON DELETE CASCADE<\/strong> \u6216 <strong>ON UPDATE CASCADE<\/strong> \u5b9e\u73b0\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">#### \u6b65\u9aa4\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4f7f\u7528 <code>ALTER TABLE<\/code> \u6765\u4fee\u6539\u5916\u952e\u7ea6\u675f\u3002\u4f8b\u5982\uff0c\u5047\u8bbe\u4f60\u8981\u4e3a\u5916\u952e\u7ea6\u675f\u6dfb\u52a0\u7ea7\u8054\u5220\u9664\u884c\u4e3a\uff1a <code>ALTER TABLE `\u5f15\u7528\u8868\u540d` DROP FOREIGN KEY `\u5916\u952e\u7ea6\u675f\u540d\u79f0`, ADD CONSTRAINT `\u5916\u952e\u7ea6\u675f\u540d\u79f0` FOREIGN KEY (`\u5916\u952e\u5b57\u6bb5`) REFERENCES `\u4e3b\u8868\u540d`(`\u4e3b\u8868\u5b57\u6bb5`) ON DELETE CASCADE;<\/code><\/li>\n\n\n\n<li>\u8fd9\u6837\uff0c\u5f53\u5220\u9664\u4e3b\u8868\u8bb0\u5f55\u65f6\uff0c\u76f8\u5173\u7684\u5916\u952e\u8868\u4e2d\u7684\u8bb0\u5f55\u5c06\u88ab\u81ea\u52a8\u5220\u9664\uff0c\u907f\u514d\u4e86\u5916\u952e\u7ea6\u675f\u7684\u51b2\u7a81\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">3. <strong>\u4e34\u65f6\u7981\u7528\u5916\u952e\u7ea6\u675f<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u67d0\u4e9b\u6570\u636e\u5e93\u7cfb\u7edf\u4e2d\uff0c\u4f60\u53ef\u4ee5\u4e34\u65f6\u7981\u7528\u5916\u952e\u7ea6\u675f\uff0c\u7136\u540e\u5220\u9664\u6570\u636e\u3002\u8fd9\u4e2a\u65b9\u6cd5\u9002\u7528\u4e8e\u67d0\u4e9b\u9700\u8981\u5feb\u901f\u5220\u9664\u8868\u6216\u6570\u636e\u7684\u60c5\u51b5\uff0c\u4f46\u901a\u5e38\u4e0d\u63a8\u8350\u5728\u751f\u4ea7\u73af\u5883\u4e2d\u4f7f\u7528\uff0c\u9664\u975e\u4f60\u975e\u5e38\u786e\u5b9a\u64cd\u4f5c\u7684\u5b89\u5168\u6027\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">#### \u5728 MySQL \u4e2d\u7981\u7528\u5916\u952e\u68c0\u67e5\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>   SET foreign_key_checks = 0;<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u7981\u7528\u5916\u952e\u68c0\u67e5\u540e\uff0c\u53ef\u4ee5\u5220\u9664\u8868\u6216\u6570\u636e\uff0c\u7136\u540e\u518d\u91cd\u65b0\u542f\u7528\u5916\u952e\u68c0\u67e5\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>   SET foreign_key_checks = 1;<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6ce8\u610f<\/strong>\uff1a\u8fd9\u79cd\u65b9\u6cd5\u4f1a\u7ed5\u8fc7\u5916\u952e\u7ea6\u675f\uff0c\u53ef\u80fd\u4f1a\u5bfc\u81f4\u6570\u636e\u7684\u4e0d\u4e00\u81f4\uff0c\u56e0\u6b64\u4f7f\u7528\u65f6\u9700\u8981\u975e\u5e38\u5c0f\u5fc3\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">4. <strong>\u68c0\u67e5\u89e6\u53d1\u5668<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u53ef\u80fd\u4f1a\u6709\u89e6\u53d1\u5668\uff08Trigger\uff09\u4f9d\u8d56\u4e8e\u5916\u952e\u7ea6\u675f\uff0c\u8fd9\u4e5f\u53ef\u80fd\u5bfc\u81f4\u5220\u9664\u5931\u8d25\u3002\u4f60\u53ef\u4ee5\u68c0\u67e5\u662f\u5426\u6709\u89e6\u53d1\u5668\u5f71\u54cd\u5220\u9664\u64cd\u4f5c\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u67e5\u770b\u8868\u7684\u89e6\u53d1\u5668\uff1a <code>SHOW TRIGGERS LIKE '\u8868\u540d';<\/code> \u5982\u679c\u6709\u89e6\u53d1\u5668\u5f71\u54cd\u5220\u9664\u64cd\u4f5c\uff0c\u53ef\u4ee5\u9009\u62e9\u7981\u7528\u89e6\u53d1\u5668\u6216\u4fee\u6539\u89e6\u53d1\u5668\u7684\u903b\u8f91\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u603b\u7ed3<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u9047\u5230 <strong>\u201c\u65e0\u6cd5\u5220\u9664\u5bf9\u8c61\uff0c\u56e0\u4e3a\u8be5\u5bf9\u8c61\u6b63\u7531\u4e00\u4e2a FOREIGN KEY \u7ea6\u675f\u5f15\u7528\u201d<\/strong> \u9519\u8bef\u65f6\uff0c\u901a\u5e38\u662f\u56e0\u4e3a\u8be5\u5bf9\u8c61\u88ab\u5176\u4ed6\u8868\u7684\u5916\u952e\u7ea6\u675f\u6240\u4f9d\u8d56\u3002\u89e3\u51b3\u65b9\u6848\u5305\u62ec\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u5220\u9664\u6216\u4fee\u6539\u5916\u952e\u7ea6\u675f\u3002<\/li>\n\n\n\n<li>\u8bbe\u7f6e\u5916\u952e\u7ea6\u675f\u7684\u7ea7\u8054\u5220\u9664\uff08<code>ON DELETE CASCADE<\/code>\uff09\u3002<\/li>\n\n\n\n<li>\u4e34\u65f6\u7981\u7528\u5916\u952e\u68c0\u67e5\uff08\u4f46\u8981\u8c28\u614e\u4f7f\u7528\uff09\u3002<\/li>\n\n\n\n<li>\u68c0\u67e5\u662f\u5426\u6709\u89e6\u53d1\u5668\u5f71\u54cd\u64cd\u4f5c\u3002<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u6839\u636e\u5177\u4f53\u60c5\u51b5\u9009\u62e9\u5408\u9002\u7684\u89e3\u51b3\u65b9\u6cd5\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 SQL \u4e2d\uff0c\u5f53\u4f60\u9047\u5230 \u201c\u65e0\u6cd5\u5220\u9664\u5bf9\u8c61\uff0c\u56e0\u4e3a\u8be5\u5bf9\u8c61\u6b63\u7531\u4e00\u4e2a FOREIGN KEY \u7ea6\u675f\u5f15\u7528\u201d* \u7684\u9519\u8bef\u65f6\uff0c [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[36],"tags":[],"class_list":["post-794","post","type-post","status-publish","format-standard","hentry","category-sql"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/794","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=794"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/794\/revisions"}],"predecessor-version":[{"id":795,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/794\/revisions\/795"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=794"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=794"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=794"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}