{"id":199700,"date":"2025-05-06T09:18:10","date_gmt":"2025-05-06T01:18:10","guid":{"rendered":"https:\/\/server.hk\/cnblog\/199700\/"},"modified":"2025-05-06T09:18:10","modified_gmt":"2025-05-06T01:18:10","slug":"%e4%b8%80%e4%b8%aasql%e8%a7%a6%e5%8f%91%e5%99%a8%e7%9a%84%e7%a4%ba%e4%be%8b","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/199700\/","title":{"rendered":"\u4e00\u4e2asql\u89e6\u53d1\u5668\u7684\u793a\u4f8b"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u4e00\u4e2asql\u89e6\u53d1\u5668\u7684\u793a\u4f8b<\/h1>\n<p>\u4e3b\u673a\u5b9d\u8d1d\u4eca\u5929\u5c06\u7ed9\u5927\u5bb6\u5e26\u6765\uff0c\u611f\u5174\u8da3\u7684\u670b\u53cb\u8bf7\u7ee7\u7eed\u770b\u4e0b\u53bb\u5427\uff01\u4ee5\u4e0b\u5185\u5bb9\u5c06\u4f1a\u6d89\u53ca\u5230\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u5982\u679c\u4f60\u662f\u6b63\u5728\u5b66\u4e60\u6216\u8005\u5df2\u7ecf\u662f\u5927\u4f6c\u7ea7\u522b\u4e86\uff0c\u90fd\u975e\u5e38\u6b22\u8fce\u4e5f\u5e0c\u671b\u5927\u5bb6\u90fd\u80fd\u7ed9\u6211\u5efa\u8bae\u8bc4\u8bba\u54c8~\u5e0c\u671b\u80fd\u5e2e\u52a9\u5230\u5927\u5bb6\uff01<\/p>\n<p>SQL\u89e6\u53d1\u5668\u662f\u4e00\u79cd\u6570\u636e\u5e93\u5bf9\u8c61\uff0c\u5b83\u80fd\u591f\u5728\u8868\u4e0a\u7684\u7279\u5b9a\u64cd\u4f5c\uff08\u4f8b\u5982\u63d2\u5165\u3001\u66f4\u65b0\u6216\u5220\u9664\uff09\u53d1\u751f\u65f6\u81ea\u52a8\u6267\u884c\u4e00\u7cfb\u5217\u7684\u52a8\u4f5c\u3002\u89e6\u53d1\u5668\u53ef\u4ee5\u5e2e\u52a9\u6211\u4eec\u5728\u7279\u5b9a\u4e8b\u4ef6\u53d1\u751f\u65f6\u81ea\u52a8\u6267\u884c\u4e00\u4e9b\u64cd\u4f5c\uff0c\u6bd4\u5982\u8bb0\u5f55\u4fee\u6539\u65e5\u5fd7\u3001\u6570\u636e\u540c\u6b65\u6216\u8005\u786e\u4fdd\u6570\u636e\u7684\u4e00\u81f4\u6027\u3002\u5728\u8fd9\u7bc7\u6587\u7ae0\u4e2d\uff0c\u6211\u5c06\u7ed9\u51fa\u51e0\u4e2aSQL\u89e6\u53d1\u5668\u7684\u5b9e\u4f8b\uff0c\u5e76\u63d0\u4f9b\u5177\u4f53\u7684\u4ee3\u7801\u793a\u4f8b\u3002<\/p>\n<p>\u793a\u4f8b\u4e00\uff1a\u5728\u8868\u7684\u6bcf\u6b21\u63d2\u5165\u8bb0\u5f55\u65f6\u81ea\u52a8\u66f4\u65b0\u8ba1\u6570\u5668\u5b57\u6bb5\u7684\u503c<br \/>\u5047\u8bbe\u6211\u4eec\u6709\u4e00\u4e2a\u8868&#8221;orders&#8221;\uff0c\u5176\u4e2d\u5305\u542b\u4e86\u8ba2\u5355\u4fe1\u606f\uff0c\u800c\u6211\u4eec\u5e0c\u671b\u6bcf\u5f53\u6709\u65b0\u7684\u8ba2\u5355\u63d2\u5165\u65f6\uff0c\u81ea\u52a8\u5c06\u8ba2\u5355\u7684\u8ba1\u6570\u5668\u5b57\u6bb5&#8221;order_count&#8221;\u52a01\u3002<\/p>\n<p>\u89e6\u53d1\u5668\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n<pre>CREATE TRIGGER update_order_count\nAFTER INSERT ON orders\nFOR EACH ROW\nBEGIN\n  UPDATE order_count\n  SET count = count + 1;\nEND;<\/pre>\n<p>\u793a\u4f8b\u4e8c\uff1a\u5728\u8868\u7684\u6bcf\u6b21\u66f4\u65b0\u8bb0\u5f55\u65f6\u81ea\u52a8\u8bb0\u5f55\u4fee\u6539\u65e5\u5fd7<br \/>\u5047\u8bbe\u6211\u4eec\u6709\u4e00\u4e2a\u8868&#8221;products&#8221;\uff0c\u5176\u4e2d\u5305\u542b\u4e86\u4ea7\u54c1\u7684\u4fe1\u606f\uff0c\u800c\u6211\u4eec\u5e0c\u671b\u6bcf\u5f53\u6709\u4ea7\u54c1\u4fe1\u606f\u88ab\u66f4\u65b0\u65f6\uff0c\u81ea\u52a8\u5728\u65e5\u5fd7\u8868&#8221;log&#8221;\u4e2d\u8bb0\u5f55\u4fee\u6539\u7684\u8be6\u7ec6\u4fe1\u606f\u3002<\/p>\n<p>\u89e6\u53d1\u5668\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n<pre>CREATE TRIGGER log_product_updates\nAFTER UPDATE ON products\nFOR EACH ROW\nBEGIN\n  INSERT INTO log (product_id, update_time, old_price, new_price)\n  VALUES (OLD.id, NOW(), OLD.price, NEW.price);\nEND;<\/pre>\n<p>\u793a\u4f8b\u4e09\uff1a\u5728\u8868\u7684\u6bcf\u6b21\u5220\u9664\u8bb0\u5f55\u65f6\u81ea\u52a8\u89e6\u53d1\u7ea7\u8054\u5220\u9664<br \/>\u5047\u8bbe\u6211\u4eec\u6709\u4e24\u4e2a\u8868&#8221;customers&#8221;\u548c&#8221;orders&#8221;\uff0c\u5176\u4e2d&#8221;customers&#8221;\u8868\u5305\u542b\u4e86\u5ba2\u6237\u7684\u4fe1\u606f\uff0c\u800c&#8221;orders&#8221;\u8868\u5305\u542b\u4e86\u8ba2\u5355\u7684\u4fe1\u606f\u3002\u6211\u4eec\u5e0c\u671b\u6bcf\u5f53\u5220\u9664&#8221;customers&#8221;\u8868\u4e2d\u7684\u67d0\u4e2a\u5ba2\u6237\u8bb0\u5f55\u65f6\uff0c\u81ea\u52a8\u5c06\u4e0e\u4e4b\u76f8\u5173\u7684\u8ba2\u5355\u8bb0\u5f55\u4e00\u540c\u5220\u9664\u3002<\/p>\n<p>\u89e6\u53d1\u5668\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n<pre>CREATE TRIGGER cascade_delete_orders\nAFTER DELETE ON customers\nFOR EACH ROW\nBEGIN\n  DELETE FROM orders WHERE customer_id = OLD.id;\nEND;<\/pre>\n<p>\u4ee5\u4e0a\u662f\u4e09\u4e2aSQL\u89e6\u53d1\u5668\u7684\u5b9e\u4f8b\uff0c\u6bcf\u4e2a\u5b9e\u4f8b\u90fd\u6f14\u793a\u4e86\u4e0d\u540c\u7684\u89e6\u53d1\u5668\u5e94\u7528\u573a\u666f\u548c\u529f\u80fd\u3002\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u6839\u636e\u5177\u4f53\u9700\u6c42\u6765\u8bbe\u8ba1\u89e6\u53d1\u5668\uff0c\u4ee5\u5b9e\u73b0\u81ea\u52a8\u5316\u7684\u64cd\u4f5c\u548c\u4e1a\u52a1\u903b\u8f91\u3002<\/p>\n<p>\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u89e6\u53d1\u5668\u7684\u4ee3\u7801\u5e94\u8be5\u7ecf\u8fc7\u4ed4\u7ec6\u7684\u6d4b\u8bd5\u548c\u9a8c\u8bc1\uff0c\u786e\u4fdd\u5176\u80fd\u591f\u6b63\u786e\u5730\u6267\u884c\u548c\u4ea7\u751f\u671f\u671b\u7684\u7ed3\u679c\u3002\u540c\u65f6\uff0c\u5728\u4f7f\u7528\u89e6\u53d1\u5668\u65f6\uff0c\u4e5f\u8981\u6ce8\u610f\u89e6\u53d1\u5668\u7684\u6027\u80fd\u5f71\u54cd\uff0c\u4ee5\u53ca\u53ef\u80fd\u5f15\u53d1\u7684\u6570\u636e\u4e00\u81f4\u6027\u548c\u6b7b\u9501\u7b49\u95ee\u9898\u3002<\/p>\n<p>\u4eca\u5929\u5173\u4e8e\u300a\u4e00\u4e2asql\u89e6\u53d1\u5668\u7684\u793a\u4f8b\u300b\u7684\u5185\u5bb9\u4ecb\u7ecd\u5c31\u5230\u6b64\u7ed3\u675f\uff0c\u5982\u679c\u6709\u4ec0\u4e48\u7591\u95ee\u6216\u8005\u5efa\u8bae\uff0c\u53ef\u4ee5\u5728\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\u4e0b\u591a\u591a\u56de\u590d\u4ea4\u6d41\uff1b\u6587\u4e2d\u82e5\u6709\u4e0d\u6b63\u4e4b\u5904\uff0c\u4e5f\u5e0c\u671b\u56de\u590d\u7559\u8a00\u4ee5\u544a\u77e5\uff01<\/p>\n<dl>\n<dt>\n 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