{"id":10020696,"date":"2025-04-03T21:02:29","date_gmt":"2025-04-03T13:02:29","guid":{"rendered":"https:\/\/itmax.cn\/?p=10020696"},"modified":"2025-04-03T21:02:29","modified_gmt":"2025-04-03T13:02:29","slug":"%e6%b4%bb%e5%8a%a8%e4%b8%ad%e5%8f%b0%e7%b3%bb%e7%bb%9f%e6%85%a2-sql-%e6%b2%bb%e7%90%86%e5%ae%9e%e8%b7%b5","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10020696","title":{"rendered":"\u6d3b\u52a8\u4e2d\u53f0\u7cfb\u7edf\u6162 SQL \u6cbb\u7406\u5b9e\u8df5"},"content":{"rendered":"<blockquote><p>\u4f5c\u8005\uff1avivo \u4e92\u8054\u7f51\u670d\u52a1\u5668\u56e2\u961f- Zhang Mengtao<\/p><\/blockquote>\n<p>\u6d3b\u52a8\u4e2d\u53f0\u7cfb\u7edf\u4f5c\u4e3a\u4e2d\u53f0\u9879\u76ee\u975e\u5e38\u6ce8\u91cd\u7cfb\u7edf\u6027\u80fd\u548c\u7528\u6237\u4f53\u9a8c\uff0c\u6570\u636e\u5e93\u7cfb\u7edf\u6027\u80fd\u95ee\u9898\u4f1a\u5bf9\u5e94\u7528\u7a0b\u5e8f\u7684\u6027\u80fd\u548c\u7528\u6237\u4f53\u9a8c\u4ea7\u751f\u8d1f\u9762\u5f71\u54cd\u3002\u6162\u67e5\u8be2\u53ef\u80fd\u5bfc\u81f4\u5e94\u7528\u7a0b\u5e8f\u54cd\u5e94\u53d8\u6162\u3001\u8bf7\u6c42\u5806\u79ef\u3001\u7cfb\u7edf\u8d1f\u8f7d\u589e\u52a0\u7b49\u95ee\u9898\uff0c\u751a\u81f3\u5f15\u53d1\u7cfb\u7edf\u5d29\u6e83\u6216\u4e0d\u53ef\u7528\u7684\u60c5\u51b5\uff0c\u56e0\u6b64\uff0c\u9700\u8981\u5728\u6570\u636e\u5e93\u7cfb\u7edf\u4e2d\u9488\u5bf9\u6267\u884c\u7f13\u6162\u7684SQL\u67e5\u8be2\u8fdb\u884c\u4f18\u5316\u548c\u6539\u8fdb\u3002\u672c\u6587\u4e3b\u8981\u4ecb\u7ecd\u6d3b\u52a8\u4e2d\u53f0\u7cfb\u7edf\u9488\u5bf9\u6162SQL\u95ee\u9898\u7684\u5b9e\u8df5\u6cbb\u7406\u6848\u4f8b\u3002<\/p>\n<h2>\u4e00\u3001\u6162 SQL \u7684\u542b\u4e49<\/h2>\n<h3>1.1 \u6162 SQL \u7684\u542b\u4e49<\/h3>\n<p>\u6162SQL\u662f\u6307\u6267\u884c\u65f6\u95f4\u8f83\u957f\u7684SQL\u67e5\u8be2\u6216\u64cd\u4f5c\u3002\u771f\u5b9e\u7684\u6162 SQL \u901a\u5e38\u4f1a\u4f34\u968f\u7740\u5927\u91cf\u7684\u884c\u626b\u63cf\u3001\u4e34\u65f6\u6587\u4ef6\u6392\u5e8f\u6216\u8005\u9891\u7e41\u7684\u78c1\u76d8 flush \uff0c\u76f4\u63a5\u5f71\u54cd\u5c31\u662f\u78c1\u76d8 IO \u5347\u9ad8\uff0c\u8ba9\u6b63\u5e38\u7684 SQL \u53d8\u6210\u4e86\u6162 SQL \uff0c\u5927\u9762\u79ef\u6267\u884c\u8d85\u65f6\u3002<\/p>\n<p>\u5927\u5bb6\u4e0d\u8981\u88ab\u6162\u67e5\u8be2\u8fd9\u4e2a\u540d\u5b57\u8bef\u5bfc\uff0c\u4ee5\u4e3a\u6162\u67e5\u8be2\u65e5\u5fd7\u53ea\u4f1a\u8bb0\u5f55 select \u8bed\u53e5\uff0c\u5176\u5b9e\u4e5f\u4f1a\u8bb0\u5f55\u6267\u884c\u65f6\u95f4\u8d85\u8fc7\u4e86long_query_time\u8bbe\u5b9a\u7684\u9608\u503c\u7684 insert\u3001update \u7b49 DML \u8bed\u53e5\u3002<\/p>\n<h3>1.2 \u6162 SQL \u7684\u5371\u5bb3<\/h3>\n<p><strong>\u4ece\u4e1a\u52a1\u7684\u89d2\u5ea6\u6765\u770b<\/strong>\uff1a\u6162 SQL \u4f1a\u5bfc\u81f4\u4ea7\u54c1\u7528\u6237\u4f53\u9a8c\u5dee\uff0c\u4f1a\u51cf\u4f4e\u7528\u6237\u5bf9\u4ea7\u54c1\u7684\u597d\u611f\u5ea6\u3002<\/p>\n<p><strong>\u4ece\u6570\u636e\u5e93\u7684\u89d2\u5ea6\u6765\u770b<\/strong>\uff1a\u6162 SQL \u4f1a\u5f71\u54cd\u6570\u636e\u5e93\u7684\u6027\u80fd\uff0c\u6bcf\u4e2a SQL \u6267\u884c\u90fd\u9700\u8981\u6d88\u8017\u4e00\u5b9a\u7684 I\/O \u8d44\u6e90\u3002\u5047\u8bbe\u603b\u8d44\u6e90\u662f100\uff0c\u6709\u4e00\u6761\u6162 SQL \u5360\u7528\u4e8630\u7684\u8d44\u6e90\u5171\u8ba11\u5206\u949f\u3002\u90a3\u4e48\u5728\u8fd91\u5206\u949f\u65f6\u95f4\u5185\uff0c\u5176\u4ed6 SQL \u80fd\u591f\u5206\u914d\u7684\u8d44\u6e90\u603b\u91cf\u5c31\u662f70\uff0c\u5982\u6b64\u5faa\u73af\uff0c\u5f53\u8d44\u6e90\u5206\u914d\u5b8c\u7684\u65f6\u5019\uff0c\u6240\u6709\u65b0\u7684 SQL \u6267\u884c\u5c06\u4f1a\u6392\u961f\u7b49\u5f85\u3002<\/p>\n<h2>\u4e8c\u3001\u6162SQL\u662f\u600e\u4e48\u4ea7\u751f\u7684\uff1f<\/h2>\n<p><strong>\u3010\u7f3a\u4e4f\u7d22\u5f15\u3011<\/strong>\uff1a\u5982\u679c\u5728\u67e5\u8be2\u4e2d\u6d89\u53ca\u5230\u7684\u5217\u6ca1\u6709\u9002\u5f53\u7684\u7d22\u5f15\uff0c\u6570\u636e\u5e93\u7cfb\u7edf\u53ef\u80fd\u9700\u8981\u6267\u884c\u5168\u8868\u626b\u63cf\u6765\u627e\u5230\u5339\u914d\u7684\u884c\uff0c\u4ece\u800c\u5bfc\u81f4\u67e5\u8be2\u53d8\u6162\u3002<\/p>\n<p><strong>\u3010\u67e5\u8be2\u6761\u4ef6\u4e0d\u5f53\u3011<\/strong>\uff1a\u67e5\u8be2\u6761\u4ef6\u8fc7\u4e8e\u590d\u6742\u3001\u4f7f\u7528\u4e86\u4e0d\u5fc5\u8981\u7684 JOIN \u64cd\u4f5c\u3001\u5b58\u5728\u5b50\u67e5\u8be2\u7b49\uff0c\u90fd\u53ef\u80fd\u5bfc\u81f4\u67e5\u8be2\u6027\u80fd\u4e0b\u964d\u3002<\/p>\n<p><strong>\u3010\u6570\u636e\u91cf\u8fc7\u5927\u3011<\/strong>\uff1a\u5f53\u6570\u636e\u8868\u4e2d\u7684\u6570\u636e\u91cf\u975e\u5e38\u5e9e\u5927\u65f6\uff0c\u5373\u4f7f\u6709\u7d22\u5f15\uff0c\u67e5\u8be2\u4e5f\u53ef\u80fd\u53d8\u5f97\u7f13\u6162\u3002<\/p>\n<p><strong>\u3010\u9501\u7b49\u5f85\u3011<\/strong>\uff1a\u5982\u679c\u67e5\u8be2\u9700\u8981\u8bbf\u95ee\u88ab\u5176\u4ed6\u4e8b\u52a1\u9501\u5b9a\u7684\u8d44\u6e90\uff0c\u5c31\u4f1a\u5bfc\u81f4\u67e5\u8be2\u963b\u585e\uff0c\u6267\u884c\u65f6\u95f4\u53d8\u957f\u3002<\/p>\n<p><strong>\u3010\u786c\u4ef6\u8d44\u6e90\u4e0d\u8db3\u3011<\/strong>\uff1a\u6570\u636e\u5e93\u670d\u52a1\u5668\u7684\u786c\u4ef6\u8d44\u6e90\uff08\u5982 CPU\u3001\u5185\u5b58\u3001\u78c1\u76d8\uff09\u4e0d\u8db3\u4ee5\u652f\u6491\u67e5\u8be2\u7684\u6267\u884c\uff0c\u4e5f\u4f1a\u5bfc\u81f4\u67e5\u8be2\u53d8\u6162\u3002<\/p>\n<p><strong>\u3010\u4e0d\u5408\u9002\u7684\u6570\u636e\u5e93\u8bbe\u8ba1\u3011<\/strong>\uff1a\u6570\u636e\u5e93\u8868\u7684\u8bbe\u8ba1\u4e0d\u5408\u7406\uff0c\u5982\u8fc7\u5ea6\u8303\u5f0f\u5316\u3001\u5197\u4f59\u6570\u636e\u7b49\uff0c\u4f1a\u5bfc\u81f4\u67e5\u8be2\u6027\u80fd\u4e0b\u964d\u3002<\/p>\n<p><strong>\u3010\u7edf\u8ba1\u4fe1\u606f\u4e0d\u51c6\u786e\u3011<\/strong>\uff1a\u6570\u636e\u5e93\u7684\u7edf\u8ba1\u4fe1\u606f\u4e0d\u51c6\u786e\u4f1a\u5bfc\u81f4\u67e5\u8be2\u4f18\u5316\u5668\u505a\u51fa\u9519\u8bef\u7684\u6267\u884c\u8ba1\u5212\uff0c\u5f71\u54cd\u67e5\u8be2\u6027\u80fd\u3002<\/p>\n<h2>\u4e09\u3001\u6162 SQL \u6cbb\u7406\u5b9e\u8df5<\/h2>\n<h3>3.1 \u95ee\u9898\u5206\u6790\u548c\u89e3\u51b3\u65b9\u6848<\/h3>\n<p>\u901a\u8fc7\u76d1\u63a7\u5e73\u53f0\u53d1\u73b0\uff0c\u9879\u76ee\u7684\u6162 SQL \u6570\u91cf\u8f83\u591a\uff0c\u6bcf\u5929\u53ef\u80fd\u4f1a\u4ea7\u751f\u51e0\u5343\u751a\u81f3\u4e0a\u4e07\u7684\u6162 SQL\uff0c\u8fd9\u5bf9\u7cfb\u7edf\u6027\u80fd\u548c\u7528\u6237\u4f53\u9a8c\u90fd\u6709\u4e0d\u5c0f\u7684\u5f71\u54cd\uff0c\u56e0\u6b64\uff0c\u4f18\u5316\u6162 SQL \u95ee\u9898\u503c\u5f97\u88ab\u91cd\u89c6\u3002\u6211\u4eec\u4ece\u4ee5\u4e0b\u51e0\u4e2a\u65b9\u9762\u8fdb\u884c\u6392\u67e5\u548c\u5206\u6790\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046412875\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\"><\/p>\n<h4>1.\u6570\u636e\u91cf<\/h4>\n<p>\u6211\u4eec\u90fd\u77e5\u9053\uff0c\u540c\u6837\u7684 SQL \u8bed\u53e5\uff0c\u5bf9\u4e8e\u4e0d\u540c\u6570\u636e\u91cf\u7684\u5e93\u8868\uff0c\u67e5\u8be2\u6548\u7387\u4e5f\u4e0d\u4e00\u6837\uff0c\u5f53\u6570\u636e\u91cf\u8fbe\u5230\u5343\u4e07\u7ea7\u751a\u81f3\u4e0a\u4ebf\uff0c\u666e\u901a\u7684\u67e5\u8be2\u8bed\u53e5\u6267\u884c\u65f6\u95f4\u53ef\u80fd\u4e5f\u4f1a\u8d85\u8fc7\u4e00\u79d2\uff0c\u8fdb\u800c\u51fa\u73b0\u6162 SQL \u95ee\u9898\u3002<\/p>\n<p>\u7ecf\u8fc7\u6392\u67e5\uff0c\u53d1\u73b0\u4e0d\u5c11\u5e93\u8868\u7684\u6570\u636e\u91cf\u5df2\u7ecf\u8fbe\u5230\u5343\u4e07\uff0c\u4e2a\u522b\u5206\u8868\u7684\u6570\u636e\u91cf\u5df2\u7ecf\u8fbe\u5230\u4e00\u4ebf\u591a\uff0c\u51e0\u5e74\u524d\u7684\u5386\u53f2\u6570\u636e\u4ecd\u7136\u4fdd\u7559\uff0c\u9700\u8981\u8fdb\u884c\u4eba\u5de5\u6e05\u7406\u3002<\/p>\n<p>\u9488\u5bf9\u6570\u636e\u91cf\u5bf9 SQL \u6267\u884c\u5e26\u6765\u7684\u5f71\u54cd\uff0c\u6211\u4eec\u53ef\u4ee5\u4ece\u4e09\u4e2a\u65b9\u9762\u89e3\u51b3\uff1a<\/p>\n<h5>\uff081\uff09\u6e05\u7406\u6570\u636e<\/h5>\n<p>\u6700\u76f4\u63a5\u7684\u65b9\u5f0f\u5c31\u662f\u5c06\u65e0\u6548\u6570\u636e\u6e05\u7406\uff0c\u5f88\u591a\u51e0\u5e74\u524d\u7684\u6570\u636e\uff0c\u51e0\u4e4e\u6ca1\u6709\u5b58\u50a8\u7684\u4ef7\u503c\uff0c\u53ef\u4ee5\u76f4\u63a5\u63d0\u4ea4\u5220\u9664\u8bed\u53e5\u8fdb\u884c\u6e05\u7406\u6389\uff0c\u5f53\u7136\uff0c\u6211\u4eec\u5728\u5220\u9664\u65f6\u8981\u6ce8\u610f\u7ebf\u4e0a\u5f71\u54cd\uff0c\u907f\u514d\u4e00\u6b21\u6027\u5220\u9664\u592a\u591a\u6570\u636e\uff0c\u5bb9\u6613\u9020\u6210\u7ebf\u4e0a\u6570\u636e\u5e93\u6548\u7387\u53d7\u5230\u5f71\u54cd\uff0c\u5bf9\u4e8e\u5355\u4e2a\u5206\u8868\u53ef\u4ee5\u91c7\u7528\u5206\u6279\u5220\u9664\uff0c\u6bcf\u4e00\u6279\u53ea\u5220\u9664\u4e00\u4e2a\u65f6\u95f4\u6bb5\uff1b\u5bf9\u4e8e\u591a\u4e2a\u5206\u8868\u53ef\u4ee5\u6309\u7167\u5206\u8868\u53bb\u5220\u9664\uff0c\u5c3d\u91cf\u51cf\u5c0f\u5bf9\u7ebf\u4e0a\u73af\u5883\u7684\u5f71\u54cd\u3002<\/p>\n<p>\u4ee5\u6d3b\u52a8\u4e2d\u53f0\u7cfb\u7edf\u7684\u7b54\u9898\u6d3b\u52a8\u4e3a\u4f8b\uff0c\u968f\u7740\u7b54\u9898\u6d3b\u52a8\u51e0\u5e74\u7684\u8fd0\u884c\uff0c\u6570\u636e\u5e93\u5df2\u7ecf\u6709\u5927\u91cf\u7684\u7528\u6237\u6570\u636e\uff0c\u76ee\u524d\u7ebf\u4e0a\u6570\u636e\u91cf\u5f88\u591a\u5230\u4e86\u5343\u4e07\u7ea7\uff0c\u4e2a\u522b\u5230\u4e86\u4e0a\u4ebf\u7684\u6570\u636e\u91cf\uff0c\u8fd9\u5bf9\u7ebf\u4e0a\u8bbf\u95ee\u5f71\u54cd\u5f88\u5927\u3002<\/p>\n<p>\u6240\u4ee5\u6211\u4eec\u8fdb\u884c\u624b\u52a8\u6e05\u7406\u6570\u636e\uff0c\u76ee\u524d\u7ebf\u4e0a\u4e00\u517110\u5f20\u5206\u8868\uff0c\u8003\u8651\u5230\u5bf9\u7ebf\u4e0a\u7528\u6237\u4e1a\u52a1\u7684\u5f71\u54cd\uff0c\u6211\u4eec\u901a\u8fc7\u4e24\u65b9\u9762<strong>\u51cf\u5c0f\u5f71\u54cd<\/strong>\uff1a<\/p>\n<p><strong>\u4e00\u662f<\/strong>\u5206\u4e94\u6b21\u8fdb\u884c\u6e05\u7406\uff0c\u6bcf\u6b21\u53ea\u6e05\u74062\/~3\u5f20\u5206\u8868\uff1b<\/p>\n<p><strong>\u4e8c\u662f<\/strong>\u5c06\u5220\u9664\u8bed\u53e5\u8f6c\u5316\u4e3a\u6839\u636e\u4e3b\u952e\u5220\u9664\uff0c\u5927\u5927\u63d0\u5347 SQL \u8bed\u53e5\u6267\u884c\u7684\u6548\u7387\u3002<\/p>\n<p>\u6700\u7ec8\u6e05\u7406\u6389\u5927\u91cf\u7684\u6d3b\u52a8\u6570\u636e\uff0c\u6211\u4eec\u91c7\u7528\u7684\u5220\u9664\u7b56\u7565\u662f\u5c06\u4e00\u5e74\u4ee5\u524d\u7684\u5386\u53f2\u6570\u636e\u8fdb\u884c\u5220\u9664\uff0c\u8fd9\u90e8\u5206\u6570\u636e\u5df2\u7ecf\u4e0d\u4f1a\u7528\u5230\uff0c\u8fd9\u4e2a\u65f6\u95f4\u8303\u56f4\u6e05\u7406\u6389\u4e86\u5927\u91cf\u7684\u65e0\u6548\u6570\u636e\u3002<\/p>\n<h5>\uff082\uff09\u5206\u5e93\u5206\u8868<\/h5>\n<p>\u624b\u52a8\u6e05\u7406\u6570\u636e\u867d\u7136\u80fd\u89e3\u51b3\u95ee\u9898\uff0c\u4f46\u662f\u6cbb\u6807\u4e0d\u6cbb\u672c\uff0c\u800c\u4e14\u5bf9\u4e8e\u4e00\u4e9b\u7279\u6b8a\u7684\u6d3b\u52a8\uff0c\u53ef\u80fd\u7559\u4e0b\u7684\u6570\u636e\u91cf\u4ecd\u7136\u5f88\u5927\uff0c\u8fd9\u4e2a\u65f6\u5019\u5982\u679c\u5e93\u8868\u7684\u6570\u636e\u91cf\u4ecd\u7136\u8f83\u5927\uff0c\u4e14\u4e0d\u80fd\u8fdb\u884c\u5220\u9664\uff0c\u5c31\u8981\u8003\u8651\u5206\u5e93\u5206\u8868\u662f\u5426\u8db3\u591f\uff0c\u53ef\u80fd\u4e4b\u524d\u51fa\u4e8e\u4e1a\u52a1\u8003\u8651\u6ca1\u6709\u8fdb\u884c\u5206\u8868\u6216\u8005\u5206\u8868\u6570\u91cf\u8f83\u5c11\uff0c\u8fd9\u4e2a\u65f6\u5019\u5c31\u8981\u8003\u8651\u8fdb\u884c\u66f4\u591a\u7684\u5206\u8868\uff0c\u4ee5\u63d0\u5347\u6570\u636e\u5e93\u8bbf\u95ee\u7684\u6548\u7387\u3002\u8fd9\u91cc\u5982\u679c\u53ef\u4ee5\u7684\u8bdd\u6700\u597d\u8bbe\u7f6e\u5206\u8868\u7b56\u7565\uff0c\u5efa\u7acb\u914d\u7f6e\u9879\uff0c\u7075\u6d3b\u6269\u5145\u5206\u8868\uff0c\u907f\u514d\u76f4\u63a5\u53d1\u7248\u3002<\/p>\n<p>\u6d3b\u52a8\u4e2d\u53f0\u7cfb\u7edf\u4f1a\u6709\u4e00\u5f20\u5355\u72ec\u7684\u8def\u7531\u8868\uff0c\u8bb0\u5f55\u5206\u8868\u8def\u7531\uff0c\u4fbf\u4e8e\u5feb\u901f\u67e5\u8be2\u5206\u8868\u3002<\/p>\n<p>\u540c\u65f6\u53ef\u4ee5\u628a\u8def\u7531\u76f8\u5173\u914d\u7f6e\u76f4\u63a5\u5efa\u7acb\u5728\u914d\u7f6e\u4e2d\u5fc3\uff0c\u65e0\u987b\u53d1\u7248\u5c31\u53ef\u4ee5\u5feb\u901f\u6269\u5206\u8868\u3002\u53ef\u4ee5\u6839\u636e\u6570\u636e\u91cf\u5927\u5c0f\u521b\u5efa10\u300120\u300150\u3001100\u5f20\u5206\u8868\u3002<\/p>\n<h5>\uff083\uff09\u5927\u6570\u636e\u91cf\u67e5\u8be2\u79fb\u6b65ES\u6570\u636e\u5e93<\/h5>\n<p>\u5f53\u7136\uff0c\u5bf9\u4e8e\u4e00\u4e9b\u54cd\u5e94\u8981\u6c42\u6bd4\u8f83\u9ad8\u7684\u4e1a\u52a1\u9700\u6c42\uff0cMySQL \u6570\u636e\u5e93\u7684\u6027\u80fd\u53ef\u80fd\u65e0\u6cd5\u8fbe\u5230\u8981\u6c42\uff0c\u8fd9\u4e2a\u65f6\u5019\u53ef\u4ee5\u8003\u8651\u5c06\u6570\u636e\u5b58\u50a8\u5728 ElasticSearch \u6570\u636e\u5e93\u6216\u8005\u7f13\u5b58\u5f53\u4e2d\u3002<\/p>\n<h4>2.SQL \u8bed\u53e5<\/h4>\n<p>\u6570\u636e\u5e93\u7684\u6570\u636e\u91cf\u662f\u91cd\u8981\u7684\u5f71\u54cd\u56e0\u7d20\uff0c\u4f46\u662f SQL \u8bed\u53e5\u672c\u8eab\u66f4\u4f1a\u5f71\u54cd\u6267\u884c\u7684\u6548\u7387\uff0c\u89c4\u8303\u7684 SQL \u8bed\u53e5\u662f\u907f\u514d\u6162 SQL \u7684\u524d\u63d0\u3002\u6839\u636e\u4e0b\u56fe\u53ef\u4ee5\u770b\u51fa\uff0cSQL \u7684\u6267\u884c\u987a\u5e8f\u4e3a\uff1a<\/p>\n<ul>\n<li>\u9996\u5148\u6267\u884c from\u3001join \u6765\u786e\u5b9a\u8868\u4e4b\u95f4\u7684\u8fde\u63a5\u5173\u7cfb\uff0c\u5f97\u5230\u521d\u6b65\u7684\u6570\u636e\u3002<\/li>\n<li>\u7136\u540e\u5229\u7528 where \u5173\u952e\u5b57\u540e\u9762\u7684\u6761\u4ef6\u5bf9\u7b26\u5408\u6761\u4ef6\u7684\u8bed\u53e5\u8fdb\u884c\u7b5b\u9009\u3002<\/li>\n<li>from \/&amp; join\/&amp;where\uff1a\u7528\u4e8e\u786e\u5b9a\u8981\u67e5\u8be2\u7684\u8868\u7684\u8303\u56f4\uff0c\u6d89\u53ca\u5230\u54ea\u4e9b\u8868\u3002<\/li>\n<\/ul>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046412876\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u90a3\u4e48\u6839\u636e\u8fd9\u4e2a\u6267\u884c\u987a\u5e8f\uff0c\u6211\u4eec\u6765\u770b\u4e0b SQL \u6267\u884c\u8fc7\u7a0b\u4e2d\u5e38\u89c1\u7684\u95ee\u9898\u6709\u54ea\u4e9b?<\/p>\n<h5>\uff081\uff09\u67e5\u8be2\u5b57\u6bb5<\/h5>\n<p>\u6211\u4eec\u5728\u9879\u76ee\u4e2d\u67e5\u8be2\u6700\u5e38\u7528\u7684\u662f\u8fd4\u56de\u6574\u4e2a DO \u5c42\u5bf9\u8c61\uff0c\u4f46\u5176\u5b9e\u5f88\u591a\u65f6\u5019\u6211\u4eec\u53ea\u9700\u8981\u5176\u4e2d\u51e0\u4e2a\u5b57\u6bb5\u751a\u81f3\u4e00\u4e2a\u5b57\u6bb5\uff0c\u8fd9\u4e2a\u65f6\u5019\u67e5\u8be2\u6574\u4e2a\u5bf9\u8c61\u662f\u5f88\u4e0d\u5212\u7b97\u7684\uff0c\u6bd4\u5982\u4e0b\u9762\u8fd9\u4e2a\u4f8b\u5b50\uff0c\u8be5\u8bed\u53e5\u5728\u6570\u636e\u5e93\u7ba1\u7406\u5668\u4e2d\u7684\u6267\u884c\u7ed3\u679c\u5982\u4e0b\uff0c\u6267\u884c\u65f6\u95f4\u4e3a9269ms\u3002<\/p>\n<pre><code>select * from a where id = 0;\n<\/code><\/pre>\n<p>\u7136\u800c\u6211\u4eec\u53ea\u662f\u60f3\u67e5\u8be2\u6307\u5b9a\u6d3b\u52a8\u4e0b\u7684\u5355\u4e2a\u5b57\u6bb5\uff0c\u8fd9\u4e2a\u65f6\u5019\u53ef\u4ee5\u4e0d\u9700\u8981\u8fd4\u56de\u5176\u4ed6\u5b57\u6bb5\uff0c\u53ea\u8fd4\u56de\u9700\u8981\u7684\u5b57\u6bb5\uff0c\u4f18\u5316\u540e\u793a\u4f8b\u5982\u4e0b\uff0c\u6267\u884c\u65f6\u95f4\u4e3a4104ms\uff0c\u660e\u663e\u6267\u884c\u65f6\u95f4\u53d8\u77ed\u4e86\u3002<\/p>\n<pre><code>select result from a where id = 0;\n<\/code><\/pre>\n<h5>\uff082\uff09\u7d22\u5f15\u95ee\u9898<\/h5>\n<p>\u7d22\u5f15\u5728\u6570\u636e\u5e93\u67e5\u8be2\u4e2d\u662f\u4e00\u4e2a\u5f88\u91cd\u8981\u7684\u5f71\u54cd\u56e0\u7d20\uff0c\u8d70\u4e0d\u5230\u7d22\u5f15\u548c\u8d70\u5230\u7d22\u5f15\u662f\u6709\u5f88\u5927\u7684\u533a\u522b\u7684\u3002\u4f46\u662f\u7d22\u5f15\u6709\u5f0a\u4e5f\u6709\u5229\uff1a<\/p>\n<p><strong>\u4f18\u70b9<\/strong><\/p>\n<ul>\n<li>\u63d0\u9ad8\u67e5\u8be2\u8bed\u53e5\u7684\u6267\u884c\u6548\u7387\uff0c\u51cf\u5c11 IO \u64cd\u4f5c\u7684\u6b21\u6570<\/li>\n<li>\u521b\u5efa\u552f\u4e00\u6027\u7d22\u5f15\uff0c\u53ef\u4ee5\u4fdd\u8bc1\u6570\u636e\u5e93\u8868\u4e2d\u6bcf\u4e00\u884c\u6570\u636e\u7684\u552f\u4e00\u6027<\/li>\n<li>\u52a0\u4e86\u7d22\u5f15\u7684\u5217\u4f1a\u8fdb\u884c\u6392\u5e8f\uff0c\u5728\u4f7f\u7528\u5206\u7ec4\u548c\u6392\u5e8f\u5b50\u53e5\u8fdb\u884c\u67e5\u8be2\u65f6\uff0c\u53ef\u4ee5\u663e\u8457\u51cf\u5c11\u67e5\u8be2\u4e2d\u5206\u7ec4\u548c\u6392\u5e8f\u7684\u65f6\u95f4<\/li>\n<\/ul>\n<p><strong>\u7f3a\u70b9<\/strong><\/p>\n<ul>\n<li>\u7d22\u5f15\u9700\u8981\u5360\u7269\u7406\u7a7a\u95f4<\/li>\n<li>\u521b\u5efa\u7d22\u5f15\u548c\u7ef4\u62a4\u7d22\u5f15\u8981\u8017\u8d39\u65f6\u95f4\uff0c\u8fd9\u79cd\u65f6\u95f4\u968f\u7740\u6570\u636e\u91cf\u7684\u589e\u52a0\u800c\u589e\u52a0<\/li>\n<li>\u5f53\u5bf9\u8868\u4e2d\u7684\u6570\u636e\u8fdb\u884c\u589e\u5220\u6539\u67e5\u65f6\uff0c\u7d22\u5f15\u4e5f\u8981\u52a8\u6001\u7684\u7ef4\u62a4\uff0c\u8fd9\u6837\u5c31\u964d\u4f4e\u4e86\u6570\u636e\u7684\u66f4\u65b0\u6548\u7387<\/li>\n<li>\u6240\u4ee5\u5408\u7406\u7684\u8bbe\u7f6e\u7d22\u5f15\u5e76\u5229\u7528\u7d22\u5f15\u662f\u9ad8\u6548\u6267\u884cSQL\u7684\u91cd\u8981\u56e0\u7d20\u3002<\/li>\n<\/ul>\n<p>\u4ee5\u4e0b\u9762\u8fd9\u4e2a\u6848\u4f8b\u6765\u5206\u6790\uff1a<\/p>\n<pre><code>CREATE TABLE `table_test` (\n`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,\n`test` varchar(128) NOT NULL DEFAULT '' COMMENT '\u7d22\u5f15\u6d4b\u8bd5\u5b57\u6bb5',\n............\n`result` varchar(128) NOT NULL DEFAULT '' COMMENT '\u7ed3\u679c\u6d4b\u8bd5\u5b57\u6bb5',\nPRIMARY KEY (`id`),\nKEY `test` (`test`),\n) COMMENT='\u8bb0\u5f55\u8868';\n<\/code><\/pre>\n<p>\u8fd9\u662f\u6d3b\u52a8\u5e73\u53f0\u7cfb\u7edf\u7eaa\u5f55\u7684\u6570\u636e\u8868\uff0c\u5176\u4e2d\u3010result\u3011\u662f\u552f\u4e00\u7684\uff0c\u8fd9\u91cc\u53ef\u4ee5\u770b\u5230\u7d22\u5f15\u6ca1\u6709\u6d89\u53ca\u3010result\u3011\uff0c\u5982\u679c\u6211\u4eec\u6839\u636e\u8fd9\u4e2a\u5b57\u6bb5\u53bb\u67e5\u8be2\u552f\u4e00\u8bb0\u5f55\uff0c\u770b\u4e0b\u6267\u884c\u7ed3\u679c\u5982\u4f55\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046412877\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u8017\u65f64286ms\uff0c\u8fd9\u91cc\u6839\u636e\u5efa\u8868\u8bed\u53e5\u53ef\u4ee5\u770b\u5230\u6709\u7d22\u5f15\u3010KEY test (test)\u3011\uff0c\u5982\u679c\u6211\u4eec\u6839\u636e\u7d22\u5f15\u5b57\u6bb5\u6765\u67e5\u8be2\u8be5\u6761\u8bb0\u5f55\u7684\u8bdd\uff0c\u770b\u4e0b\u6267\u884c\u7ed3\u679c\u5982\u4f55\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046412878\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u53ef\u4ee5\u770b\u5230\u53ea\u9700\u898116ms\uff0c\u7d22\u5f15\u5bf9\u6570\u636e\u5e93\u6548\u7387\u7684\u63d0\u5347\u81f3\u5173\u91cd\u8981\u3002\u6211\u4eec\u53ef\u4ee5\u6839\u636e explain \u5173\u952e\u5b57\u6765\u89e3\u6790\u4e00\u4e0b SQL \u8bed\u53e5\uff0c\u6bd4\u5982\u521a\u624d\u7684\u6848\u4f8b\uff0c\u6211\u4eec\u6765\u770b\u4e0b\u76f8\u5e94\u7684\u7ed3\u679c\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046412879\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046412880\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u53ef\u4ee5\u770b\u5230\uff0c\u76f4\u63a5\u6839\u636e\u975e\u7d22\u5f15\u5b57\u6bb5\u3010result\u3011\u67e5\u8be2\uff0ctype \u5b57\u6bb5\u503c\u4e3a\u3010ALL\u3011\uff0c\u4ee3\u8868\u904d\u5386\u5168\u8868\uff0c\u626b\u63cf\u884c\u6570\u4e3a3144273\uff0c\u5982\u679c\u5e26\u4e0a\u7d22\u5f15\u5b57\u6bb5\u3010test\u3011\uff0ctype \u5b57\u6bb5\u503c\u4e3a\u3010ref\u3011\uff0c\u4ee3\u8868\u5339\u914d\u5230\u5355\u884c\u8bb0\u5f55\u503c\uff0c\u626b\u63cf\u884c\u6570\u4e3a1\uff0c\u663e\u7136\u901a\u8fc7\u7d22\u5f15\u67e5\u8be2\u6548\u7387\u5f97\u5230\u4e86\u6781\u5927\u7684\u63d0\u5347\u3002\u5bf9\u4e8e\u7d22\u5f15\u7684\u4f7f\u7528\u4f1a\u51fa\u73b0\u4ee5\u4e0b\u51e0\u79cd<strong>\u5e38\u89c1\u7c7b\u578b<\/strong>\uff1a<\/p>\n<p><strong>ALL<\/strong>\uff1a\u5168\u8868\u626b\u63cf\uff0c\u8868\u793a MySQL \u5c06\u904d\u5386\u6574\u4e2a\u8868\u4ee5\u6ee1\u8db3\u67e5\u8be2\u6761\u4ef6\u3002\u8fd9\u901a\u5e38\u662f\u6548\u7387\u6700\u4f4e\u7684\u8bbf\u95ee\u7c7b\u578b\uff0c\u5e94\u5c3d\u91cf\u907f\u514d\u3002<\/p>\n<p><strong>index<\/strong>\uff1a\u7d22\u5f15\u5168\u626b\u63cf\uff0c\u8868\u793a MySQL \u5c06\u904d\u5386\u6574\u4e2a\u7d22\u5f15\u4ee5\u6ee1\u8db3\u67e5\u8be2\u6761\u4ef6\uff0c\u800c\u4e0d\u662f\u904d\u5386\u6574\u4e2a\u8868\u3002\u867d\u7136\u6bd4\u5168\u8868\u626b\u63cf\u6548\u7387\u8981\u9ad8\uff0c\u4f46\u4ecd\u7136\u9700\u8981\u904d\u5386\u7d22\u5f15\u7684\u6bcf\u4e00\u884c\u3002<\/p>\n<p><strong>range<\/strong>\uff1a\u8303\u56f4\u626b\u63cf\uff0c\u8868\u793a MySQL \u4f7f\u7528\u4e86\u7d22\u5f15\u7684\u4e00\u90e8\u5206\u6765\u6ee1\u8db3\u67e5\u8be2\u6761\u4ef6\uff0c\u4f8b\u5982\u4f7f\u7528\u4e86\u7d22\u5f15\u7684\u67d0\u4e2a\u8303\u56f4\u3002\u8fd9\u901a\u5e38\u53d1\u751f\u5728\u6709\u8303\u56f4\u67e5\u8be2\u6761\u4ef6\u65f6\uff0c\u4f8b\u5982\u4f7f\u7528\u4e86 WHERE \u5b50\u53e5\u4e2d\u7684 BETWEEN\u3001\/&gt;\u3001\/&lt; \u7b49\u64cd\u4f5c\u7b26\u3002<\/p>\n<p><strong>index_merge<\/strong>\uff1a\u7d22\u5f15\u5408\u5e76\uff0c\u8868\u793a MySQL \u4f7f\u7528\u4e86\u591a\u4e2a\u7d22\u5f15\u6765\u6ee1\u8db3\u67e5\u8be2\u6761\u4ef6\uff0c\u7136\u540e\u5c06\u7ed3\u679c\u5408\u5e76\u3002\u8fd9\u901a\u5e38\u53d1\u751f\u5728\u67e5\u8be2\u4e2d\u6709\u591a\u4e2a\u6761\u4ef6\uff0c\u6bcf\u4e2a\u6761\u4ef6\u53ef\u4ee5\u4f7f\u7528\u4e0d\u540c\u7684\u7d22\u5f15\u6765\u8bbf\u95ee\u6570\u636e\u3002<\/p>\n<p><strong>unique_subquery<\/strong>\uff1a\u552f\u4e00\u5b50\u67e5\u8be2\uff0c\u8868\u793a MySQL \u4f7f\u7528\u4e86\u5b50\u67e5\u8be2\u6765\u83b7\u53d6\u552f\u4e00\u7684\u7ed3\u679c\uff0c\u5e76\u4e14\u5b50\u67e5\u8be2\u4f7f\u7528\u4e86\u552f\u4e00\u7d22\u5f15\u3002<\/p>\n<p><strong>const<\/strong>\uff1a\u5e38\u91cf\uff0c\u8868\u793a MySQL \u4f7f\u7528\u4e86\u5e38\u91cf\u8868\u6765\u83b7\u53d6\u7ed3\u679c\uff0c\u8fd9\u901a\u5e38\u53d1\u751f\u5728\u67e5\u8be2\u6761\u4ef6\u4e2d\u5305\u542b\u4e86\u5e38\u91cf\u503c\u3002<\/p>\n<p><strong>ref<\/strong>\uff1a\u5f15\u7528\uff0c\u8868\u793a MySQL \u4f7f\u7528\u4e86\u975e\u552f\u4e00\u7d22\u5f15\u6765\u626b\u63cf\u8868\uff0c\u901a\u5e38\u53d1\u751f\u5728\u67e5\u8be2\u4e2d\u4f7f\u7528\u4e86\u5355\u4e2a\u7d22\u5f15\u5217\u4f5c\u4e3a\u6761\u4ef6\u3002<\/p>\n<h5>\uff083\uff09\u8054\u8868\u67e5\u8be2<\/h5>\n<p>\u3010<strong>JOIN<\/strong>\u3011\u5173\u952e\u8bcd\u5728\u9879\u76ee\u7684\u65e5\u5e38\u67e5\u8be2\u4e2d\u53ef\u80fd\u4f1a\u9047\u5230\uff0c\u5bf9\u4e8e\u4e00\u4e9b\u7ba1\u7406\u53f0\u9879\u76ee\u53ef\u80fd\u8981\u6c42\u8f83\u4f4e\uff0c\u53ef\u4ee5\u4f5c\u4e3a\u65e5\u5e38\u5f00\u53d1\u67e5\u8be2\u8bed\u53e5\uff0c\u4f46\u662f\u5bf9\u4e8e\u9762\u5411\u7528\u6237\u7684\u9879\u76ee\uff0c\u7531\u4e8e\u6570\u636e\u91cf\u8f83\u5927\uff0c\u5f80\u5f80\u9700\u8981\u907f\u514d\u8054\u5408\u67e5\u8be2\u7684\u4f7f\u7528\u3002\u4ee5\u4e0b\u9762\u8fd9\u4e2a\u6848\u4f8b\u6765\u5206\u6790\uff1a<\/p>\n<pre><code>select * from a left join b on a.id = b.id where a.id = 0;\n<\/code><\/pre>\n<p>\u8fd9\u4e2aSQL\u662f\u8054\u5408\u591a\u5f20\u8868\u8fdb\u884c\u8054\u5408\u67e5\u8be2\uff0c\u8fd8\u6709\u5176\u4ed6\u67e5\u8be2\u6761\u4ef6\uff0c\u6267\u884c\u5f97\u51fa\u7ed3\u679c\u65f6\u95f4\u4e3a1432ms\uff0c\u8d85\u8fc71\u79d2\u5219\u4e3a\u6162 SQL\uff0c\u8fd9\u91cc\u8054\u5408\u4e24\u5f20\u8868\uff0c\u5982\u679c\u76f8\u5173\u7684\u6570\u636e\u91cf\u8f83\u5927\uff0c\u5219\u6267\u884c\u901f\u5ea6\u4f1a\u8f83\u6162\u3002\u6211\u4eec\u53ef\u4ee5\u5c06 SQL \u62c6\u5206\u4e3a\u4e24\u4e2a\u8bed\u53e5\u6267\u884c\uff0c\u62c6\u4e3a\u4ee5\u4e0b\u4e24\u4e2a SQL \u5206\u6b65\u6267\u884c\uff1a<\/p>\n<pre><code>select * from a where id = 0;\nselect * from b where id = 0;\n<\/code><\/pre>\n<p>\u5206\u6b65\u83b7\u53d6\u6570\u636e\u5e93\u7ed3\u679c\u540e\u518d\u8fdb\u884c\u805a\u5408\uff0c\u5206\u6b65\u6267\u884c\u7ed3\u679c\u5206\u522b\u4e3a728ms\u548c744ms\uff0c\u8054\u5408\u67e5\u8be2\u62c6\u5206\u4e3a\u7b80\u5355\u67e5\u8be2\u53ef\u4ee5\u6709\u6548\u51cf\u5c11\u6162 SQL\uff0c\u540c\u65f6\u53ef\u4ee5\u63d0\u9ad8SQL\u67e5\u8be2\u7684\u590d\u7528\u6027\u3002<\/p>\n<h5>\uff084\uff09\u6761\u4ef6\u67e5\u8be2<\/h5>\n<p>\u5728\u9879\u76ee\u7684\u65e5\u5e38\u5f00\u53d1\u4e2d\uff0cSQL \u8bed\u53e5\u5207\u5fcc\u4f7f\u7528\u590d\u6742\u67e5\u8be2\uff0c\u8fd9\u4f1a\u5bf9\u6570\u636e\u5e93\u9020\u6210\u8f83\u5927\u7684\u538b\u529b\u3002\u4e0b\u9762\u8fd9\u4e2a\u4f8b\u5b50\u5c31\u662f\u4f7f\u7528\u4e86\u6bd4\u8f83\u590d\u6742\u7684\u6761\u4ef6\u67e5\u8be2\uff1a<\/p>\n<pre><code>select * from a where id in (select id from b) and time &gt; '2024-03-29';\n<\/code><\/pre>\n<p>\u4f7f\u7528\u67e5\u8be2\u6761\u4ef6\u7684\u540c\u65f6\u8fd8\u5d4c\u5957\u4e86\u67e5\u8be2\u8bed\u53e5\uff0c\u9664\u6b64\u4e4b\u5916\u8fd8\u5939\u6742\u4e86\u8054\u5408\u67e5\u8be2\uff0c\u8bed\u53e5\u5df2\u7ecf\u6bd4\u8f83\u590d\u6742\uff0c\u6211\u4eec\u6765\u770b\u4e0b\u67e5\u8be2\u7ed3\u679c\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046412881\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u53ef\u4ee5\u770b\u5230\u6267\u884c\u65f6\u95f4\u975e\u5e38\u7f13\u6162\uff0c\u8fbe\u523012648ms\uff0c\u8fd9\u4e2aSQL\u7684\u80cc\u666f\u662f\u7528\u4e8e\u4e1a\u52a1\u5bf9\u8d26\uff0c\u867d\u7136\u4f7f\u7528\u7684\u662f\u79bb\u7ebf\u6570\u636e\u5e93\uff0c\u4f46\u662f\u4ecd\u7136\u4e0d\u80fd\u5ffd\u89c6\u5b83\u7684\u98ce\u9669\uff0c\u6bcf\u5929\u5927\u91cf\u7684\u6267\u884c\u8fd9\u79cd\u590d\u6742 SQL\uff0c\u8fd8\u662f\u5bf9\u4e1a\u52a1\u6709\u4e00\u5b9a\u7684\u98ce\u9669\u5f71\u54cd\u3002\u8003\u8651\u5230\u4e1a\u52a1\u4ef7\u503c\u5355\u4e00\uff0c\u590d\u7528\u6027\u4e0d\u9ad8\uff0c\u6211\u4eec\u53ef\u4ee5\u76f4\u63a5\u5197\u4f59\u4e00\u4efd\u6570\u636e\u5230\u5355\u72ec\u7684\u8868\u91cc\uff0c\u907f\u514d\u590d\u6742\u67e5\u8be2\uff0c\u76f4\u63a5\u4e00\u6b65\u5230\u4f4d\u89e3\u51b3\u5bf9\u8d26\u5e26\u6765\u7684\u6162 SQL \u95ee\u9898\u3002<\/p>\n<h4>3. \u6574\u4f53\u7b56\u7565<\/h4>\n<p>\u6e05\u7406\u5b8c\u6570\u636e\u5e93\u7684\u65e0\u6548\u6570\u636e\uff0c\u4f18\u5316\u5b8c SQL \u8bed\u53e5\u672c\u8eab\uff0c\u53ef\u80fd\u8fd8\u662f\u4f1a\u51fa\u73b0\u6162 SQL \u95ee\u9898\uff0c\u8fd9\u4e2a\u65f6\u5019\u6211\u4eec\u8981\u8003\u8651\u4e0b\uff0c\u662f\u5426\u53ef\u4ee5\u4f18\u5316\u6574\u4f53\u7684\u6570\u636e\u5e93\u4ea4\u4e92\u7b56\u7565\uff0c\u4ee5\u6d3b\u52a8\u4e2d\u53f0\u7cfb\u7edf\u7684\u6570\u636e\u6e05\u7406\u6162 SQL \u4e3a\u4f8b\u3002<\/p>\n<p>\u6d3b\u52a8\u4e2d\u53f0\u7cfb\u7edf\u521b\u5efa\u4e86\u4e00\u4e2a\u5b9a\u65f6\u4efb\u52a1\uff0c\u6bcf\u5929\u51cc\u6668\u6267\u884c\u4e00\u6b21\uff0c\u5bf9\u6570\u636e\u5e93\u7684\u65e0\u6548\u5386\u53f2\u6570\u636e\u8fdb\u884c\u7edf\u4e00\u6e05\u7406\uff0c\u5177\u4f53\u5220\u9664\u54ea\u4e9b\u5e93\u8868\u3001\u4ec0\u4e48\u65f6\u95f4\u6bb5\u3001\u4ec0\u4e48\u6761\u4ef6\u90fd\u7531\u914d\u7f6e\u9879\u7075\u6d3b\u63a7\u5236\uff0c\u914d\u7f6e\u9879\u793a\u4f8b\u5982\u4e0b\uff1a<\/p>\n<pre><code>&quot;\u5206\u8868\u6570\u91cf&quot;\uff1a7,\n&quot;\u8868\u540d&quot;\uff1atable,\n&quot;\u6761\u4ef6&quot;\uff1acondition\n<\/code><\/pre>\n<p>\u5305\u62ec\u5206\u8868\u7684\u6570\u91cf\u3001\u8981\u5220\u9664\u6570\u636e\u7684\u8868\u540d\u3001\u67e5\u8be2\u7684\u6761\u4ef6\u4fe1\u606f\uff0c\u67e5\u8be2\u6761\u4ef6\u5bf9\u5e94SQL\u8bed\u53e5\u4e2d\u7684\u3010where\u3011\u4fe1\u606f\u3002\u6267\u884c\u6d41\u7a0b\u5982\u4e0b\u56fe\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046412882\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u6574\u4f53\u4e0a\u770b\u5220\u9664\u7b56\u7565\u5f88\u901a\u7528\uff0c\u6761\u4ef6\u914d\u7f6e\u7075\u6d3b\uff0c\u53ef\u4ee5\u540c\u65f6\u5e94\u5bf9\u4e0d\u540c\u5206\u8868\u3001\u4e0d\u540c\u67e5\u8be2\u6761\u4ef6\u7b49\u3002\u4f46\u662f\u7ebf\u4e0a\u8fd0\u884c\u53d1\u73b0\u4f1a\u4ea7\u751f\u5927\u91cf\u7684\u6162SQL\uff0c\u53ef\u80fd\u6bcf\u5929\u5c31\u4f1a\u4ea7\u751f\u51e0\u5343\u6761\u3002<\/p>\n<p>\u4e3b\u8981\u539f\u56e0\u5982\u4e0b\uff1a<\/p>\n<blockquote>\n<ul>\n<li>\u4f1a\u51fa\u73b0\u8054\u8868\u67e5\u8be2\u7684\u60c5\u51b5\uff0c\u6570\u636e\u91cf\u8f83\u5927\u7684\u8868\u4f1a\u51fa\u73b0\u6267\u884c\u65f6\u95f4\u8d85\u8fc7\u4e00\u79d2\u7684 SQL \u8bed\u53e5\uff1b<\/li>\n<li>\u5220\u9664\u7b56\u7565\u4e2d\u65f6\u95f4\u662f\u91cd\u8981\u7684\u56e0\u7d20\uff0c\u4f46\u662f\u65f6\u95f4\u5f80\u5f80\u4e0d\u4f1a\u8bbe\u7f6e\u4e3a\u7d22\u5f15\u5b57\u6bb5\uff0c\u6240\u4ee5\u5f88\u96be\u5145\u5206\u5229\u7528\u7d22\u5f15\uff1b<\/li>\n<li>\u5220\u9664\u7b56\u7565\u4f1a\u626b\u63cf\u6240\u6709\u5206\u8868\uff0c\u4f46\u662f\u5f88\u591a\u5206\u8868\u53ef\u80fd\u5168\u90e8\u626b\u63cf\u4e5f\u6ca1\u6709\u9700\u8981\u5220\u9664\u7684\u6570\u636e\uff0c\u4f1a\u51fa\u73b0\u65e0\u6548\u6267\u884c\u7684\u60c5\u51b5\u3002<\/li>\n<\/ul>\n<\/blockquote>\n<p>\u9488\u5bf9\u4ee5\u4e0a\u7b56\u7565\uff0c\u6211\u4eec\u8fdb\u884c\u4e86\u7efc\u5408\u6539\u8fdb\uff0c\u4e3b\u8981\u63aa\u65bd\u6709\u4ee5\u4e0b\u51e0\u6761\uff1a<\/p>\n<blockquote>\n<ul>\n<li>\u907f\u514d\u8054\u8868\u67e5\u8be2\uff0c\u5c3d\u53ef\u80fd\u7684\u62c6\u5206\u4e3a\u7b80\u5355 SQL \u6267\u884c\uff1b<\/li>\n<li>\u4e0d\u8981\u4ece\u65f6\u95f4\u7ef4\u5ea6\u76f4\u63a5\u51fa\u53d1\uff0c\u800c\u662f\u4ece\u6d3b\u52a8\u7ef4\u5ea6\u51fa\u53d1\uff0c\u5982\u679c\u4e00\u4e2a\u6d3b\u52a8\u7ed3\u675f\u65f6\u95f4\u8f83\u957f\uff0c\u90a3\u4e48\u8fd9\u4e2a\u6d3b\u52a8\u76f8\u5173\u7684\u6570\u636e\u81ea\u7136\u4e0d\u518d\u9700\u8981\uff0c\u53ef\u4ee5\u76f4\u63a5\u5220\u9664\uff1b<\/li>\n<li>\u5229\u7528\u5206\u8868\u8def\u7531\u4fe1\u606f\uff0c\u4ece\u6d3b\u52a8\u672c\u8eab\u51fa\u53d1\u5feb\u901f\u8def\u7531\u5230\u76f8\u5173\u5206\u8868\uff0c\u51cf\u5c11 SQL \u8bed\u53e5\u7684\u65e0\u6548\u6267\u884c\u3002<\/li>\n<\/ul>\n<\/blockquote>\n<p>\u4fee\u6539\u5b8c\u7684\u914d\u7f6e\u9879\u5982\u4e0b\uff1a<\/p>\n<pre><code>&quot;\u5206\u8868\u6570\u91cf&quot;\uff1a7,\n&quot;\u8868\u540d&quot;\uff1atable,\n&quot;\u6761\u4ef6&quot;\uff1acondition,\n&quot;\u5220\u9664\u6570\u91cf&quot;\uff1a1,\n&quot;\u5220\u9664\u7b56\u7565&quot;:1,\n&quot;\u5f00\u59cb\u65f6\u95f4&quot;:&quot;&quot;,\n&quot;\u7ed3\u675f\u65f6\u95f4&quot;:&quot;&quot;\n<\/code><\/pre>\n<p>\u5305\u62ec\u5206\u8868\u7684\u6570\u91cf\u3001\u8981\u5220\u9664\u6570\u636e\u7684\u8868\u540d\u3001\u67e5\u8be2\u6761\u4ef6\u3001\u6bcf\u6b21\u5220\u9664\u7684\u6570\u91cf\u3001\u5f00\u59cb\u65f6\u95f4\u548c\u7ed3\u675f\u65f6\u95f4\uff0c\u5728\u8fd9\u4e2a\u65f6\u95f4\u8303\u56f4\u5185\u7684\u6d3b\u52a8\u90fd\u7b26\u5408\u6761\u4ef6\uff0c\u6574\u4f53\u4e0a\u770b\u5220\u9664\u7b56\u7565\u66f4\u4e3a\u901a\u7528\uff0c\u6761\u4ef6\u914d\u7f6e\u66f4\u52a0\u7075\u6d3b\u3002\u4f18\u5316\u7684\u5220\u9664\u7b56\u7565\u6d41\u7a0b\u56fe\u5982\u4e0b\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046412883\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u4ece\u56fe\u4e2d\u53ef\u4ee5\u770b\u5230\uff0c\u6211\u4eec\u4fdd\u7559\u539f\u6709\u7684\u5220\u9664\u7b56\u7565\uff0c\u907f\u514d\u4e2a\u522b\u6570\u636e\u8868\u6ca1\u6709\u6d3b\u52a8\u4fe1\u606f\u548c\u5206\u8868\u4fe1\u606f\uff0c\u53ea\u80fd\u5355\u7eaf\u6839\u636e\u65f6\u95f4\u626b\u63cf\u5220\u9664\uff1b\u9664\u6b64\u4e4b\u5916\uff0c\u5bf9\u4e8e\u6709\u6d3b\u52a8\u4fe1\u606f\u7684\u6570\u636e\uff0c\u6211\u4eec\u4f1a\u5148\u67e5\u8be2\u6d3b\u52a8\uff0c\u6839\u636e\u6d3b\u52a8\u53bb\u5220\u9664\uff0c\u5982\u679c\u6570\u636e\u8868\u662f\u6839\u636e\u6d3b\u52a8\u8fdb\u884c\u5206\u8868\uff0c\u5219\u76f4\u63a5\u67e5\u8be2\u8def\u7531\u4fe1\u606f\uff0c\u5e76\u5220\u9664\u6307\u5b9a\u5206\u8868\u7684\u6570\u636e\u5373\u53ef\uff0c\u4e5f\u5c31\u662f\u56fe\u4e2d\u7684\u7b2c\u4e09\u79cd\u7b56\u7565\uff0c\u7ebf\u4e0a\u5927\u90e8\u5206\u7684\u6570\u636e\u90fd\u4f1a\u6309\u7167\u7b2c\u4e09\u79cd\u7b56\u7565\u6267\u884c\uff0c\u5982\u679c\u6709\u6d3b\u52a8\u4fe1\u606f\u4f46\u662f\u672a\u6309\u7167\u6d3b\u52a8\u8fdb\u884c\u5206\u8868\uff0c\u53ef\u80fd\u6309\u7167\u7528\u6237\u7b49\u7ef4\u5ea6\u8fdb\u884c\u5206\u8868\uff0c\u5219\u53ef\u4ee5\u6839\u636e\u6d3b\u52a8\u4fe1\u606f\u8fdb\u884c\u5220\u9664\uff0c\u4e5f\u53ef\u4ee5\u6709\u6548\u907f\u514d\u6162 SQL \u7684\u51fa\u73b0\u3002<\/p>\n<h3>3.2 \u6cbb\u7406\u6548\u679c<\/h3>\n<p>\u7ecf\u8fc7\u5bf9\u6162 SQL \u7684\u4e13\u9879\u6cbb\u7406\uff0c\u6d3b\u52a8\u4e2d\u53f0\u7cfb\u7edf\u7684\u6162 SQL \u6570\u91cf\u7531\u51e0\u5343\u4e2a\uff0c\u7a33\u5b9a\u5728\u4e86\u4e24\u4f4d\u6570\uff0c\u6709\u6548\u51cf\u5c11\u4e86\u6162SQL\u7684\u6570\u91cf\uff0c\u8fdb\u4e00\u6b65\u63d0\u5347\u4e86\u7cfb\u7edf\u7a33\u5b9a\u6027\u3002<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046412884\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<h2>\u56db\u3001\u7ecf\u9a8c\u603b\u7ed3<\/h2>\n<ul>\n<li>\u6cbb\u7406\u6162 SQL \u7684\u6839\u672c\u662f\u4ece\u6e90\u5934\u907f\u514d\u6162 SQL\uff0c\u9879\u76ee\u7ec4\u5185\u90e8\u5fc5\u987b\u8fbe\u6210\u9ad8\u5ea6\u4e00\u81f4\uff0c\u6839\u636e\u7f16\u7801\u89c4\u8303\u8fdb\u884c\u524d\u7f6e\u907f\u514d\u6162 SQL \u7684\u51fa\u73b0\u3002<\/li>\n<li>\u79bb\u7ebf\u6570\u636e\u5e93\u4e0d\u80fd\u6210\u4e3a\u5ffd\u89c6\u6162 SQL \u95ee\u9898\u7684\u539f\u56e0\uff0c\u4ecd\u7136\u4f1a\u6709\u5f71\u54cd\u7ebf\u4e0a\u4e1a\u52a1\u7684\u98ce\u9669\uff0c\u6570\u636e\u5e93\u5b9e\u4f8b\u5982\u679c\u662f\u6df7\u5408\u90e8\u7f72\u7684\u65b9\u5f0f\uff0c\u53ef\u80fd\u79bb\u7ebf\u5e93\u6240\u5728\u7684\u673a\u5668\u6709\u5176\u4ed6\u4e1a\u52a1\u7684\u4e3b\u5e93\uff0c\u800c\u4e14\u5982\u679c\u4ece\u5e93\u5ef6\u8fdf\u4e25\u91cd\u4f1a\u5f71\u54cd\u4e3b\u4ece\u6545\u969c\u5207\u6362\u3002<\/li>\n<li>\u6570\u636e\u5e93\u7684\u5408\u7406\u8bbe\u8ba1\u4e0d\u80fd\u4f9d\u8d56\u540e\u671f\u91cd\u6784\uff0c\u4e00\u5f00\u59cb\u5c31\u8981\u5c3d\u53ef\u80fd\u7684\u8003\u8651\u5145\u5206\u3002<\/li>\n<li>\u6162 SQL \u6cbb\u7406\u8fc7\u7a0b\u4e2d\u51fa\u73b0\u7684\u95ee\u9898\u53ef\u4ee5\u53ca\u65f6\u590d\u76d8\uff0c\u907f\u514d\u56e2\u961f\u5176\u4ed6\u6210\u5458\u7ee7\u7eed\u8e29\u5751\u3002<\/li>\n<\/ul>\n<p><a href=\"https:\/\/segmentfault.com\/a\/1190000046412873\">https:\/\/segmentfault.com\/a\/1190000046412873<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4f5c\u8005\uff1avivo \u4e92\u8054\u7f51\u670d\u52a1\u5668\u56e2\u961f- Zhang Mengtao \u6d3b\u52a8\u4e2d\u53f0\u7cfb\u7edf\u4f5c\u4e3a\u4e2d\u53f0\u9879\u76ee\u975e\u5e38\u6ce8\u91cd\u7cfb\u7edf\u6027\u80fd\u548c\u7528\u6237 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[4],"tags":[],"class_list":["post-10020696","post","type-post","status-publish","format-standard","hentry","category-share"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10020696","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10020696"}],"version-history":[{"count":0,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10020696\/revisions"}],"wp:attachment":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10020696"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10020696"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10020696"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}