{"id":6597,"date":"2024-11-14T10:28:14","date_gmt":"2024-11-14T02:28:14","guid":{"rendered":"https:\/\/fwq.ai\/blog\/6597\/"},"modified":"2024-11-14T10:28:14","modified_gmt":"2024-11-14T02:28:14","slug":"mysql%e8%a7%a6%e5%8f%91%e5%99%a8%e7%9a%84%e4%bd%9c%e7%94%a8","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/6597\/","title":{"rendered":"mysql\u89e6\u53d1\u5668\u7684\u4f5c\u7528"},"content":{"rendered":"<blockquote><p>\n  \u89e6\u53d1\u5668\u662f\u4e00\u79cd\u6570\u636e\u5e93\u5bf9\u8c61\uff0c\u53ef\u5728\u8868\u4e0a\u7684\u7279\u5b9a\u4e8b\u4ef6\uff08\u63d2\u5165\u3001\u66f4\u65b0\u6216\u5220\u9664\uff09\u53d1\u751f\u65f6\u81ea\u52a8\u6267\u884c sql \u8bed\u53e5\u3002\u5176\u4f5c\u7528\u5305\u62ec\uff1a\u7ef4\u62a4\u6570\u636e\u5b8c\u6574\u6027\uff0c\u786e\u4fdd\u8868\u4e2d\u6570\u636e\u7b26\u5408\u7279\u5b9a\u89c4\u5219\u81ea\u52a8\u6267\u884c\u4efb\u52a1\uff0c\u5982\u53d1\u9001\u7535\u5b50\u90ae\u4ef6\u3001\u66f4\u65b0\u5176\u4ed6\u8868\u5b9e\u73b0\u590d\u6742\u7684\u4e1a\u52a1\u903b\u8f91\u63d0\u9ad8\u6027\u80fd\uff0c\u907f\u514d\u91cd\u590d\u6267\u884c\u76f8\u540c\u4efb\u52a1\n<\/p><\/blockquote>\n<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/202408\/06\/2024080618462896909.jpg\" class=\"aligncenter\" title=\"mysql\u89e6\u53d1\u5668\u7684\u4f5c\u7528\u63d2\u56fe\" alt=\"mysql\u89e6\u53d1\u5668\u7684\u4f5c\u7528\u63d2\u56fe\" \/><\/p>\n<p><strong>MySQL \u89e6\u53d1\u5668\u7684\u4f5c\u7528<\/strong><\/p>\n<p>MySQL \u89e6\u53d1\u5668\u662f\u4e00\u79cd\u6570\u636e\u5e93\u5bf9\u8c61\uff0c\u5b83\u5141\u8bb8\u5728\u8868\u4e0a\u7684\u7279\u5b9a\u4e8b\u4ef6\uff08\u4f8b\u5982 INSERT\u3001UPDATE \u6216 DELETE\uff09\u53d1\u751f\u65f6\u81ea\u52a8\u6267\u884c\u4e00\u7ec4 SQL \u8bed\u53e5\u3002<\/p>\n<p><strong>\u89e6\u53d1\u5668\u6709\u54ea\u4e9b\u4f5c\u7528\uff1f<\/strong><\/p>\n<p>\u89e6\u53d1\u5668\u6709\u4ee5\u4e0b\u4e3b\u8981\u4f5c\u7528\uff1a<\/p>\n<ul>\n<li> <strong>\u7ef4\u62a4\u6570\u636e\u5b8c\u6574\u6027\uff1a<\/strong>\u89e6\u53d1\u5668\u53ef\u4ee5\u786e\u4fdd\u8868\u4e2d\u7684\u6570\u636e\u59cb\u7ec8\u4fdd\u6301\u7279\u5b9a\u89c4\u5219\uff0c\u4f8b\u5982\u786e\u4fdd\u5217\u7684\u552f\u4e00\u6027\u6216\u503c\u57df\u9650\u5236\u3002<\/li>\n<li> <strong>\u81ea\u52a8\u6267\u884c\u4efb\u52a1\uff1a<\/strong>\u89e6\u53d1\u5668\u53ef\u4ee5\u5728\u6570\u636e\u4fee\u6539\u540e\u81ea\u52a8\u6267\u884c\u8bf8\u5982\u53d1\u9001\u7535\u5b50\u90ae\u4ef6\u3001\u66f4\u65b0\u5176\u4ed6\u8868\u6216\u8c03\u7528\u5b58\u50a8\u8fc7\u7a0b\u7b49\u4efb\u52a1\u3002<\/li>\n<li> <strong>\u5b9e\u73b0\u4e1a\u52a1\u903b\u8f91\uff1a<\/strong>\u89e6\u53d1\u5668\u53ef\u4ee5\u7528\u4e8e\u5b9e\u73b0\u590d\u6742\u7684\u4e1a\u52a1\u903b\u8f91\uff0c\u8fd9\u4e9b\u903b\u8f91\u53ef\u80fd\u96be\u4ee5\u6216\u4e0d\u53ef\u80fd\u901a\u8fc7\u7b80\u5355\u7684 SQL \u8bed\u53e5\u6765\u5b9e\u73b0\u3002<\/li>\n<li> <strong>\u63d0\u9ad8\u6027\u80fd\uff1a<\/strong>\u89e6\u53d1\u5668\u53ef\u4ee5\u901a\u8fc7\u907f\u514d\u5728\u6bcf\u4e2a\u6570\u636e\u4fee\u6539\u8bed\u53e5\u4e2d\u91cd\u590d\u6267\u884c\u76f8\u540c\u7684\u4efb\u52a1\u6765\u63d0\u9ad8\u6027\u80fd\u3002<\/li>\n<\/ul>\n<p><strong>\u89e6\u53d1\u5668\u7684\u7ed3\u6784<\/strong><\/p>\n<p>\u4e00\u4e2a\u89e6\u53d1\u5668\u7531\u4ee5\u4e0b\u90e8\u5206\u7ec4\u6210\uff1a<\/p>\n<ul>\n<li> <strong>\u89e6\u53d1\u7c7b\u578b\uff1a<\/strong>\u6307\u5b9a\u5728\u54ea\u4e2a\u4e8b\u4ef6\u4e0a\u89e6\u53d1\u89e6\u53d1\u5668\uff0c\u4f8b\u5982 INSERT\u3001UPDATE \u6216 DELETE\u3002<\/li>\n<li> <strong>\u89e6\u53d1\u65f6\u95f4\uff1a<\/strong>\u6307\u5b9a\u662f\u5728\u4e8b\u4ef6\u4e4b\u524d\uff08BEFORE\uff09\u8fd8\u662f\u4e4b\u540e\uff08AFTER\uff09\u89e6\u53d1\u89e6\u53d1\u5668\u3002<\/li>\n<li> <strong>\u89e6\u53d1\u4f53\uff1a<\/strong>\u5305\u542b\u8981\u6267\u884c\u7684 SQL \u8bed\u53e5\u7684\u89e6\u53d1\u5668\u4ee3\u7801\u5757\u3002<\/li>\n<\/ul>\n<p><strong>\u4f7f\u7528\u89e6\u53d1\u5668<\/strong><\/p>\n<p>\u8981\u521b\u5efa\u89e6\u53d1\u5668\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8bed\u6cd5\uff1a<\/p>\n<pre>CREATE TRIGGER trigger_name\nBEFORE\/AFTER [INSERT|UPDATE|DELETE] ON table_name\nFOR EACH ROW\nBEGIN\n  -- \u89e6\u53d1\u5668\u4ee3\u7801\nEND;<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p><strong>\u793a\u4f8b<\/strong><\/p>\n<p>\u4ee5\u4e0b\u89e6\u53d1\u5668\u786e\u4fdd\u8868 users \u4e2d\u7684 username \u5217\u59cb\u7ec8\u552f\u4e00\uff1a<\/p>\n<pre>CREATE TRIGGER unique_username BEFORE INSERT ON users\nFOR EACH ROW\nBEGIN\n  IF EXISTS (SELECT 1 FROM users WHERE username = NEW.username) THEN\n    SIGNAL SQLSTATE '23000' SET MESSAGE_TEXT = 'Username already exists';\n  END IF;\nEND;<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u4ee5\u4e0a\u5c31\u662f\u89e6\u53d1\u5668\u7684\u4f5c\u7528\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>\u89e6\u53d1\u5668\u662f\u4e00\u79cd\u6570\u636e\u5e93\u5bf9\u8c61\uff0c\u53ef\u5728\u8868\u4e0a\u7684\u7279\u5b9a\u4e8b\u4ef6\uff08\u63d2\u5165\u3001\u66f4\u65b0\u6216\u5220\u9664\uff09\u53d1\u751f\u65f6\u81ea\u52a8\u6267\u884c sql \u8bed\u53e5\u3002\u5176\u4f5c\u7528\u5305\u62ec\uff1a\u7ef4\u62a4\u6570\u636e\u5b8c\u6574\u6027\uff0c\u786e\u4fdd\u8868\u4e2d\u6570\u636e\u7b26\u5408\u7279\u5b9a\u89c4\u5219\u81ea\u52a8\u6267\u884c\u4efb\u52a1\uff0c\u5982\u53d1\u9001\u7535\u5b50\u90ae\u4ef6\u3001\u66f4\u65b0\u5176\u4ed6\u8868\u5b9e\u73b0\u590d\u6742\u7684\u4e1a\u52a1\u903b\u8f91\u63d0\u9ad8\u6027\u80fd\uff0c\u907f\u514d\u91cd\u590d\u6267\u884c\u76f8\u540c\u4efb\u52a1 MySQL \u89e6\u53d1\u5668\u7684\u4f5c\u7528 MySQL \u89e6\u53d1\u5668\u662f\u4e00\u79cd\u6570\u636e\u5e93\u5bf9\u8c61\uff0c\u5b83\u5141\u8bb8\u5728\u8868\u4e0a\u7684\u7279\u5b9a\u4e8b\u4ef6\uff08\u4f8b\u5982 INSERT\u3001UPDATE \u6216 DELETE\uff09\u53d1\u751f\u65f6\u81ea\u52a8\u6267\u884c\u4e00\u7ec4 SQL \u8bed\u53e5\u3002 \u89e6\u53d1\u5668\u6709\u54ea\u4e9b\u4f5c\u7528\uff1f \u89e6\u53d1\u5668\u6709\u4ee5\u4e0b\u4e3b\u8981\u4f5c\u7528\uff1a \u7ef4\u62a4\u6570\u636e\u5b8c\u6574\u6027\uff1a\u89e6\u53d1\u5668\u53ef\u4ee5\u786e\u4fdd\u8868\u4e2d\u7684\u6570\u636e\u59cb\u7ec8\u4fdd\u6301\u7279\u5b9a\u89c4\u5219\uff0c\u4f8b\u5982\u786e\u4fdd\u5217\u7684\u552f\u4e00\u6027\u6216\u503c\u57df\u9650\u5236\u3002 \u81ea\u52a8\u6267\u884c\u4efb\u52a1\uff1a\u89e6\u53d1\u5668\u53ef\u4ee5\u5728\u6570\u636e\u4fee\u6539\u540e\u81ea\u52a8\u6267\u884c\u8bf8\u5982\u53d1\u9001\u7535\u5b50\u90ae\u4ef6\u3001\u66f4\u65b0\u5176\u4ed6\u8868\u6216\u8c03\u7528\u5b58\u50a8\u8fc7\u7a0b\u7b49\u4efb\u52a1\u3002 \u5b9e\u73b0\u4e1a\u52a1\u903b\u8f91\uff1a\u89e6\u53d1\u5668\u53ef\u4ee5\u7528\u4e8e\u5b9e\u73b0\u590d\u6742\u7684\u4e1a\u52a1\u903b\u8f91\uff0c\u8fd9\u4e9b\u903b\u8f91\u53ef\u80fd\u96be\u4ee5\u6216\u4e0d\u53ef\u80fd\u901a\u8fc7\u7b80\u5355\u7684 SQL \u8bed\u53e5\u6765\u5b9e\u73b0\u3002 \u63d0\u9ad8\u6027\u80fd\uff1a\u89e6\u53d1\u5668\u53ef\u4ee5\u901a\u8fc7\u907f\u514d\u5728\u6bcf\u4e2a\u6570\u636e\u4fee\u6539\u8bed\u53e5\u4e2d\u91cd\u590d\u6267\u884c\u76f8\u540c\u7684\u4efb\u52a1\u6765\u63d0\u9ad8\u6027\u80fd\u3002 \u89e6\u53d1\u5668\u7684\u7ed3\u6784 \u4e00\u4e2a\u89e6\u53d1\u5668\u7531\u4ee5\u4e0b\u90e8\u5206\u7ec4\u6210\uff1a \u89e6\u53d1\u7c7b\u578b\uff1a\u6307\u5b9a\u5728\u54ea\u4e2a\u4e8b\u4ef6\u4e0a\u89e6\u53d1\u89e6\u53d1\u5668\uff0c\u4f8b\u5982 INSERT\u3001UPDATE \u6216 DELETE\u3002 \u89e6\u53d1\u65f6\u95f4\uff1a\u6307\u5b9a\u662f\u5728\u4e8b\u4ef6\u4e4b\u524d\uff08BEFORE\uff09\u8fd8\u662f\u4e4b\u540e\uff08AFTER\uff09\u89e6\u53d1\u89e6\u53d1\u5668\u3002 \u89e6\u53d1\u4f53\uff1a\u5305\u542b\u8981\u6267\u884c\u7684 SQL \u8bed\u53e5\u7684\u89e6\u53d1\u5668\u4ee3\u7801\u5757\u3002 \u4f7f\u7528\u89e6\u53d1\u5668 \u8981\u521b\u5efa\u89e6\u53d1\u5668\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8bed\u6cd5\uff1a CREATE TRIGGER trigger_name BEFORE\/AFTER [INSERT|UPDATE|DELETE] ON table_name FOR EACH ROW BEGIN &#8212; \u89e6\u53d1\u5668\u4ee3\u7801 END; \u767b\u5f55\u540e\u590d\u5236 \u793a\u4f8b \u4ee5\u4e0b\u89e6\u53d1\u5668\u786e\u4fdd\u8868 users \u4e2d\u7684 username \u5217\u59cb\u7ec8\u552f\u4e00\uff1a CREATE TRIGGER [&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-6597","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/6597","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=6597"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/6597\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=6597"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=6597"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=6597"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}