{"id":157670,"date":"2024-11-02T23:30:20","date_gmt":"2024-11-02T15:30:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/157670\/"},"modified":"2024-11-02T23:30:21","modified_gmt":"2024-11-02T15:30:21","slug":"%e9%ab%98%e6%95%88-mysql-%e6%95%b8%e6%93%9a%e5%ba%ab%e7%9a%84%e6%ad%a3%e7%a2%ba%e7%b7%a8%e5%af%ab","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/157670\/","title":{"rendered":"\u9ad8\u6548 MySQL \u6578\u64da\u5eab\u7684\u6b63\u78ba\u7de8\u5beb"},"content":{"rendered":"<h1 id=\"%e9%ab%98%e6%95%88-mysql-%e6%95%b8%e6%93%9a%e5%ba%ab%e7%9a%84%e6%ad%a3%e7%a2%ba%e7%b7%a8%e5%af%ab-OVdYKXuUmL\">\u9ad8\u6548 MySQL \u6578\u64da\u5eab\u7684\u6b63\u78ba\u7de8\u5beb<\/h1>\n<p>\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u4e16\u754c\u4e2d\uff0cMySQL \u4f5c\u70ba\u4e00\u7a2e\u6d41\u884c\u7684\u958b\u6e90\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u5ee3\u6cdb\u61c9\u7528\u65bc\u5404\u7a2e\u61c9\u7528\u7a0b\u5e8f\u4e2d\u3002\u7121\u8ad6\u662f\u5c0f\u578b\u7db2\u7ad9\u9084\u662f\u5927\u578b\u4f01\u696d\u7cfb\u7d71\uff0c\u6b63\u78ba\u7de8\u5beb MySQL \u6578\u64da\u5eab\u4e0d\u50c5\u80fd\u63d0\u9ad8\u6027\u80fd\uff0c\u9084\u80fd\u78ba\u4fdd\u6578\u64da\u7684\u5b8c\u6574\u6027\u548c\u5b89\u5168\u6027\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u9ad8\u6548 MySQL \u6578\u64da\u5eab\u7684\u6b63\u78ba\u7de8\u5beb\u65b9\u6cd5\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u512a\u5316\u5176\u6578\u64da\u5eab\u8a2d\u8a08\u548c\u67e5\u8a62\u6027\u80fd\u3002<\/p>\n<h2 id=\"1-%e6%95%b8%e6%93%9a%e5%ba%ab%e8%a8%ad%e8%a8%88%e7%9a%84%e6%9c%80%e4%bd%b3%e5%af%a6%e8%b8%90-OVdYKXuUmL\">1. \u6578\u64da\u5eab\u8a2d\u8a08\u7684\u6700\u4f73\u5be6\u8e10<\/h2>\n<p>\u6578\u64da\u5eab\u7684\u8a2d\u8a08\u662f\u5f71\u97ff\u6027\u80fd\u7684\u95dc\u9375\u56e0\u7d20\u4e4b\u4e00\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u8a2d\u8a08\u4e0a\u7684\u6700\u4f73\u5be6\u8e10\uff1a<\/p>\n<ul>\n<li><strong>\u6b63\u898f\u5316<\/strong>\uff1a\u901a\u904e\u6b63\u898f\u5316\u4f86\u6d88\u9664\u6578\u64da\u5197\u9918\uff0c\u78ba\u4fdd\u6578\u64da\u7684\u4e00\u81f4\u6027\u3002\u901a\u5e38\uff0c\u7b2c\u4e00\u3001\u7b2c\u4e8c\u548c\u7b2c\u4e09\u6b63\u898f\u5f62\u662f\u6700\u5e38\u7528\u7684\u6b63\u898f\u5316\u5f62\u5f0f\u3002<\/li>\n<li><strong>\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u985e\u578b<\/strong>\uff1a\u6839\u64da\u5be6\u969b\u9700\u6c42\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u985e\u578b\u3002\u4f8b\u5982\uff0c\u5c0d\u65bc\u6574\u6578\u6578\u64da\uff0c\u4f7f\u7528 INT \u800c\u4e0d\u662f VARCHAR\uff0c\u53ef\u4ee5\u7bc0\u7701\u5b58\u5132\u7a7a\u9593\u4e26\u63d0\u9ad8\u67e5\u8a62\u901f\u5ea6\u3002<\/li>\n<li><strong>\u5efa\u7acb\u7d22\u5f15<\/strong>\uff1a\u7d22\u5f15\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002\u5c0d\u65bc\u7d93\u5e38\u7528\u65bc\u67e5\u8a62\u7684\u5217\uff0c\u61c9\u8003\u616e\u5efa\u7acb\u7d22\u5f15\uff0c\u4f46\u8981\u6ce8\u610f\u904e\u591a\u7684\u7d22\u5f15\u6703\u5f71\u97ff\u5beb\u5165\u6027\u80fd\u3002<\/li>\n<\/ul>\n<h2 id=\"2-%e6%9f%a5%e8%a9%a2%e5%84%aa%e5%8c%96-OVdYKXuUmL\">2. \u67e5\u8a62\u512a\u5316<\/h2>\n<p>\u7de8\u5beb\u9ad8\u6548\u7684 SQL \u67e5\u8a62\u662f\u63d0\u9ad8 MySQL \u6578\u64da\u5eab\u6027\u80fd\u7684\u53e6\u4e00\u500b\u91cd\u8981\u65b9\u9762\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u67e5\u8a62\u512a\u5316\u7684\u6280\u5de7\uff1a<\/p>\n<ul>\n<li><strong>\u907f\u514d SELECT *<\/strong>\uff1a\u4f7f\u7528\u5177\u9ad4\u7684\u5217\u540d\u800c\u4e0d\u662f SELECT *\uff0c\u9019\u6a23\u53ef\u4ee5\u6e1b\u5c11\u4e0d\u5fc5\u8981\u7684\u6578\u64da\u50b3\u8f38\u3002<\/li>\n<li><strong>\u4f7f\u7528 JOIN \u800c\u975e\u5b50\u67e5\u8a62<\/strong>\uff1a\u5728\u8a31\u591a\u60c5\u6cc1\u4e0b\uff0c\u4f7f\u7528 JOIN \u4f86\u9023\u63a5\u8868\u6bd4\u4f7f\u7528\u5b50\u67e5\u8a62\u66f4\u9ad8\u6548\u3002<\/li>\n<li><strong>\u9650\u5236\u7d50\u679c\u96c6<\/strong>\uff1a\u4f7f\u7528 LIMIT \u5b50\u53e5\u4f86\u9650\u5236\u67e5\u8a62\u7d50\u679c\u7684\u6578\u91cf\uff0c\u7279\u5225\u662f\u5728\u8655\u7406\u5927\u91cf\u6578\u64da\u6642\u3002<\/li>\n<\/ul>\n<h3 id=\"%e7%af%84%e4%be%8b%ef%bc%9a%e6%9f%a5%e8%a9%a2%e5%84%aa%e5%8c%96-OVdYKXuUmL\">\u7bc4\u4f8b\uff1a\u67e5\u8a62\u512a\u5316<\/h3>\n<pre><code>SELECT name, email FROM users WHERE status = 'active' LIMIT 10;<\/code><\/pre>\n<p>\u4e0a\u8ff0\u67e5\u8a62\u50c5\u9078\u64c7\u4e86\u5fc5\u8981\u7684\u5217\uff0c\u4e26\u9650\u5236\u4e86\u8fd4\u56de\u7684\u884c\u6578\uff0c\u5f9e\u800c\u63d0\u9ad8\u4e86\u6027\u80fd\u3002<\/p>\n<h2 id=\"3-%e7%9b%a3%e6%8e%a7%e5%92%8c%e8%aa%bf%e6%95%b4-OVdYKXuUmL\">3. \u76e3\u63a7\u548c\u8abf\u6574<\/h2>\n<p>\u6301\u7e8c\u76e3\u63a7\u6578\u64da\u5eab\u6027\u80fd\u662f\u78ba\u4fdd\u5176\u9ad8\u6548\u904b\u884c\u7684\u95dc\u9375\u3002\u53ef\u4ee5\u4f7f\u7528 MySQL \u7684\u6027\u80fd\u76e3\u63a7\u5de5\u5177\uff0c\u5982 <code>EXPLAIN<\/code> \u8a9e\u53e5\u4f86\u5206\u6790\u67e5\u8a62\u8a08\u5283\uff0c\u627e\u51fa\u6027\u80fd\u74f6\u9838\u3002<\/p>\n<pre><code>EXPLAIN SELECT name, email FROM users WHERE status = 'active';<\/code><\/pre>\n<p>\u6839\u64da\u5206\u6790\u7d50\u679c\uff0c\u8abf\u6574\u7d22\u5f15\u6216\u67e5\u8a62\u7d50\u69cb\uff0c\u4ee5\u9054\u5230\u6700\u4f73\u6027\u80fd\u3002<\/p>\n<h2 id=\"4-%e5%ae%89%e5%85%a8%e6%80%a7%e8%80%83%e9%87%8f-OVdYKXuUmL\">4. \u5b89\u5168\u6027\u8003\u91cf<\/h2>\n<p>\u5728\u8a2d\u8a08\u548c\u7de8\u5beb MySQL \u6578\u64da\u5eab\u6642\uff0c\u5b89\u5168\u6027\u540c\u6a23\u4e0d\u53ef\u5ffd\u8996\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5b89\u5168\u6027\u6700\u4f73\u5be6\u8e10\uff1a<\/p>\n<ul>\n<li><strong>\u4f7f\u7528\u53c3\u6578\u5316\u67e5\u8a62<\/strong>\uff1a\u9632\u6b62 SQL \u6ce8\u5165\u653b\u64ca\uff0c\u78ba\u4fdd\u6578\u64da\u7684\u5b89\u5168\u6027\u3002<\/li>\n<li><strong>\u5b9a\u671f\u5099\u4efd\u6578\u64da<\/strong>\uff1a\u5b9a\u671f\u5099\u4efd\u53ef\u4ee5\u9632\u6b62\u6578\u64da\u4e1f\u5931\uff0c\u4e26\u78ba\u4fdd\u5728\u767c\u751f\u6545\u969c\u6642\u80fd\u5920\u5feb\u901f\u6062\u5fa9\u3002<\/li>\n<li><strong>\u9650\u5236\u7528\u6236\u6b0a\u9650<\/strong>\uff1a\u6839\u64da\u7528\u6236\u7684\u5be6\u969b\u9700\u6c42\uff0c\u9650\u5236\u5176\u5c0d\u6578\u64da\u5eab\u7684\u8a2a\u554f\u6b0a\u9650\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-OVdYKXuUmL\">\u7e3d\u7d50<\/h2>\n<p>\u9ad8\u6548\u7684 MySQL \u6578\u64da\u5eab\u7de8\u5beb\u9700\u8981\u5f9e\u8a2d\u8a08\u3001\u67e5\u8a62\u512a\u5316\u3001\u6027\u80fd\u76e3\u63a7\u548c\u5b89\u5168\u6027\u7b49\u591a\u65b9\u9762\u5165\u624b\u3002\u901a\u904e\u9075\u5faa\u4e0a\u8ff0\u6700\u4f73\u5be6\u8e10\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u6578\u64da\u5eab\u7684\u6027\u80fd\u548c\u5b89\u5168\u6027\u3002\u82e5\u60a8\u9700\u8981\u9032\u4e00\u6b65\u7684\u652f\u6301\u6216\u89e3\u6c7a\u65b9\u6848\uff0c\u8acb\u8003\u616e\u6211\u5011\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u670d\u52d9\uff0c\u70ba\u60a8\u7684\u6578\u64da\u5eab\u63d0\u4f9b\u7a69\u5b9a\u7684\u904b\u884c\u74b0\u5883\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5b78\u7fd2\u9ad8\u6548 MySQL \u6578\u64da\u5eab\u7684\u6b63\u78ba\u7de8\u5beb\u6280\u5de7\uff0c\u63d0\u5347\u6027\u80fd\u8207\u53ef\u7dad\u8b77\u6027\uff0c\u78ba\u4fdd\u6578\u64da\u7ba1\u7406\u7684\u6700\u4f73\u5be6\u8e10\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-157670","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/157670","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=157670"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/157670\/revisions"}],"predecessor-version":[{"id":157671,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/157670\/revisions\/157671"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=157670"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=157670"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=157670"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}