{"id":74914,"date":"2024-10-15T23:00:25","date_gmt":"2024-10-15T15:00:25","guid":{"rendered":"https:\/\/server.hk\/cnblog\/74914\/"},"modified":"2024-10-15T23:00:25","modified_gmt":"2024-10-15T15:00:25","slug":"mysql-sql%e5%84%aa%e5%8c%96%e7%9a%84%e5%af%a6%e7%8f%be%e4%b8%a6%e4%b8%8d%e9%9b%a3","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/74914\/","title":{"rendered":"MySQL SQL\u512a\u5316\u7684\u5be6\u73fe\u4e26\u4e0d\u96e3"},"content":{"rendered":"<h1 id=\"mysql-sql%e5%84%aa%e5%8c%96%e7%9a%84%e5%af%a6%e7%8f%be%e4%b8%a6%e4%b8%8d%e9%9b%a3-jXtHYbcItj\">MySQL SQL\u512a\u5316\u7684\u5be6\u73fe\u4e26\u4e0d\u96e3<\/h1>\n<p>\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u4e16\u754c\u4e2d\uff0c\u6578\u64da\u5eab\u7684\u6027\u80fd\u5c0d\u65bc\u61c9\u7528\u7a0b\u5e8f\u7684\u6574\u9ad4\u6548\u7387\u81f3\u95dc\u91cd\u8981\u3002MySQL\u4f5c\u70ba\u4e00\u500b\u6d41\u884c\u7684\u958b\u6e90\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u5ee3\u6cdb\u61c9\u7528\u65bc\u5404\u7a2e\u7db2\u7ad9\u548c\u61c9\u7528\u7a0b\u5e8f\u4e2d\u3002\u96a8\u8457\u6578\u64da\u91cf\u7684\u589e\u9577\uff0c\u5982\u4f55\u512a\u5316MySQL\u7684\u6027\u80fd\u6210\u70ba\u4e86\u958b\u767c\u8005\u548c\u7cfb\u7d71\u7ba1\u7406\u54e1\u9762\u81e8\u7684\u4e00\u500b\u91cd\u8981\u6311\u6230\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u4e00\u4e9b\u7c21\u55ae\u800c\u6709\u6548\u7684MySQL SQL\u512a\u5316\u6280\u8853\uff0c\u5e6b\u52a9\u60a8\u63d0\u5347\u6578\u64da\u5eab\u7684\u6027\u80fd\u3002<\/p>\n<h2 id=\"1-%e4%bd%bf%e7%94%a8%e7%b4%a2%e5%bc%95-jXtHYbcItj\">1. \u4f7f\u7528\u7d22\u5f15<\/h2>\n<p>\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u7684\u95dc\u9375\u3002\u901a\u904e\u5728\u8868\u7684\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff0cMySQL\u53ef\u4ee5\u66f4\u5feb\u5730\u67e5\u627e\u6578\u64da\u3002\u4ee5\u4e0b\u662f\u5275\u5efa\u7d22\u5f15\u7684\u57fa\u672c\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>CREATE INDEX index_name ON table_name (column_name);<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5982\u679c\u60a8\u6709\u4e00\u500b\u7528\u6236\u8868\uff0c\u4e26\u4e14\u7d93\u5e38\u6839\u64da\u7528\u6236\u540d\u67e5\u8a62\uff0c\u60a8\u53ef\u4ee5\u9019\u6a23\u5275\u5efa\u7d22\u5f15\uff1a<\/p>\n<pre><code>CREATE INDEX idx_username ON users (username);<\/code><\/pre>\n<p>\u7136\u800c\uff0c\u904e\u591a\u7684\u7d22\u5f15\u6703\u5f71\u97ff\u5beb\u5165\u6027\u80fd\uff0c\u56e0\u6b64\u9700\u8981\u6839\u64da\u5be6\u969b\u60c5\u6cc1\u9032\u884c\u5e73\u8861\u3002<\/p>\n<h2 id=\"2-%e5%84%aa%e5%8c%96%e6%9f%a5%e8%a9%a2%e8%aa%9e%e5%8f%a5-jXtHYbcItj\">2. \u512a\u5316\u67e5\u8a62\u8a9e\u53e5<\/h2>\n<p>\u64b0\u5beb\u9ad8\u6548\u7684SQL\u67e5\u8a62\u8a9e\u53e5\u662f\u512a\u5316\u7684\u53e6\u4e00\u500b\u91cd\u8981\u65b9\u9762\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u512a\u5316\u67e5\u8a62\u7684\u5efa\u8b70\uff1a<\/p>\n<ul>\n<li>\u907f\u514d\u4f7f\u7528SELECT *\uff0c\u800c\u662f\u9078\u64c7\u9700\u8981\u7684\u5217\u3002<\/li>\n<li>\u4f7f\u7528JOIN\u800c\u4e0d\u662f\u5b50\u67e5\u8a62\uff0c\u56e0\u70baJOIN\u901a\u5e38\u66f4\u9ad8\u6548\u3002<\/li>\n<li>\u4f7f\u7528LIMIT\u9650\u5236\u8fd4\u56de\u7684\u884c\u6578\uff0c\u7279\u5225\u662f\u5728\u8655\u7406\u5927\u91cf\u6578\u64da\u6642\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u4ee5\u4e0b\u67e5\u8a62\u53ef\u4ee5\u9032\u884c\u512a\u5316\uff1a<\/p>\n<pre><code>SELECT * FROM users WHERE age &gt; 30;<\/code><\/pre>\n<p>\u53ef\u4ee5\u6539\u70ba\uff1a<\/p>\n<pre><code>SELECT username, email FROM users WHERE age &gt; 30 LIMIT 10;<\/code><\/pre>\n<h2 id=\"3-%e8%aa%bf%e6%95%b4mysql%e9%85%8d%e7%bd%ae-jXtHYbcItj\">3. \u8abf\u6574MySQL\u914d\u7f6e<\/h2>\n<p>MySQL\u7684\u6027\u80fd\u4e5f\u53d7\u5230\u5176\u914d\u7f6e\u7684\u5f71\u97ff\u3002\u6839\u64da\u60a8\u7684\u786c\u4ef6\u548c\u61c9\u7528\u9700\u6c42\uff0c\u8abf\u6574\u4ee5\u4e0b\u53c3\u6578\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u6027\u80fd\uff1a<\/p>\n<ul>\n<li><strong>innodb_buffer_pool_size<\/strong>: \u9019\u662fInnoDB\u5b58\u5132\u5f15\u64ce\u7528\u4f86\u7de9\u5b58\u6578\u64da\u548c\u7d22\u5f15\u7684\u5167\u5b58\u5927\u5c0f\u3002\u901a\u5e38\u5efa\u8b70\u8a2d\u7f6e\u70ba\u53ef\u7528\u5167\u5b58\u768470-80%\u3002<\/li>\n<li><strong>query_cache_size<\/strong>: \u555f\u7528\u67e5\u8a62\u7de9\u5b58\u53ef\u4ee5\u52a0\u901f\u91cd\u8907\u67e5\u8a62\u7684\u97ff\u61c9\u6642\u9593\u3002<\/li>\n<li><strong>max_connections<\/strong>: \u6839\u64da\u61c9\u7528\u7684\u4e26\u767c\u9700\u6c42\u8abf\u6574\u6700\u5927\u9023\u63a5\u6578\u3002<\/li>\n<\/ul>\n<p>\u9019\u4e9b\u914d\u7f6e\u7684\u5177\u9ad4\u503c\u9700\u8981\u6839\u64da\u5be6\u969b\u60c5\u6cc1\u9032\u884c\u8abf\u6574\uff0c\u5efa\u8b70\u5728\u9032\u884c\u66f4\u6539\u5f8c\u9032\u884c\u6027\u80fd\u6e2c\u8a66\u3002<\/p>\n<h2 id=\"4-%e5%ae%9a%e6%9c%9f%e7%b6%ad%e8%ad%b7%e6%95%b8%e6%93%9a%e5%ba%ab-jXtHYbcItj\">4. \u5b9a\u671f\u7dad\u8b77\u6578\u64da\u5eab<\/h2>\n<p>\u5b9a\u671f\u7dad\u8b77\u6578\u64da\u5eab\u53ef\u4ee5\u9632\u6b62\u6027\u80fd\u4e0b\u964d\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u7dad\u8b77\u5efa\u8b70\uff1a<\/p>\n<ul>\n<li>\u5b9a\u671f\u57f7\u884cOPTIMIZE TABLE\u547d\u4ee4\uff0c\u4ee5\u91cd\u5efa\u548c\u58d3\u7e2e\u8868\u3002<\/li>\n<li>\u4f7f\u7528ANALYZE TABLE\u547d\u4ee4\u66f4\u65b0\u8868\u7684\u7d71\u8a08\u4fe1\u606f\uff0c\u5e6b\u52a9\u67e5\u8a62\u512a\u5316\u5668\u505a\u51fa\u66f4\u597d\u7684\u6c7a\u7b56\u3002<\/li>\n<li>\u6e05\u7406\u4e0d\u518d\u4f7f\u7528\u7684\u6578\u64da\u548c\u8868\uff0c\u4ee5\u6e1b\u5c11\u6578\u64da\u5eab\u7684\u8ca0\u64d4\u3002<\/li>\n<\/ul>\n<h2 id=\"5-%e4%bd%bf%e7%94%a8explain%e5%88%86%e6%9e%90%e6%9f%a5%e8%a9%a2-jXtHYbcItj\">5. \u4f7f\u7528EXPLAIN\u5206\u6790\u67e5\u8a62<\/h2>\n<p>MySQL\u63d0\u4f9b\u4e86EXPLAIN\u547d\u4ee4\uff0c\u53ef\u4ee5\u5e6b\u52a9\u60a8\u5206\u6790\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\u3002\u901a\u904e\u67e5\u770bEXPLAIN\u7684\u8f38\u51fa\uff0c\u60a8\u53ef\u4ee5\u4e86\u89e3\u67e5\u8a62\u7684\u6027\u80fd\u74f6\u9838\uff0c\u4e26\u9032\u884c\u91dd\u5c0d\u6027\u7684\u512a\u5316\u3002<\/p>\n<pre><code>EXPLAIN SELECT username FROM users WHERE age &gt; 30;<\/code><\/pre>\n<p>\u6839\u64daEXPLAIN\u7684\u7d50\u679c\uff0c\u60a8\u53ef\u4ee5\u8abf\u6574\u7d22\u5f15\u6216\u67e5\u8a62\u7d50\u69cb\uff0c\u4ee5\u63d0\u9ad8\u6027\u80fd\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-jXtHYbcItj\">\u7e3d\u7d50<\/h2>\n<p>MySQL SQL\u512a\u5316\u7684\u5be6\u73fe\u4e26\u4e0d\u96e3\uff0c\u901a\u904e\u5408\u7406\u4f7f\u7528\u7d22\u5f15\u3001\u512a\u5316\u67e5\u8a62\u8a9e\u53e5\u3001\u8abf\u6574\u914d\u7f6e\u3001\u5b9a\u671f\u7dad\u8b77\u4ee5\u53ca\u4f7f\u7528EXPLAIN\u5206\u6790\u67e5\u8a62\uff0c\u60a8\u53ef\u4ee5\u986f\u8457\u63d0\u5347\u6578\u64da\u5eab\u7684\u6027\u80fd\u3002\u9019\u4e9b\u6280\u8853\u4e0d\u50c5\u9069\u7528\u65bc\u5c0f\u578b\u61c9\u7528\uff0c\u4e5f\u80fd\u5920\u61c9\u5c0d\u5927\u578b\u7cfb\u7d71\u7684\u6311\u6230\u3002\u82e5\u60a8\u9700\u8981\u66f4\u9ad8\u6548\u7684\u6578\u64da\u8655\u7406\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u6216<a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a>\u4f86\u652f\u6301\u60a8\u7684MySQL\u6578\u64da\u5eab\uff0c\u78ba\u4fdd\u5176\u5728\u6700\u4f73\u74b0\u5883\u4e2d\u904b\u884c\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22MySQL SQL\u512a\u5316\u7684\u7c21\u55ae\u5be6\u73fe\u65b9\u6cd5\uff0c\u63d0\u5347\u6578\u64da\u5eab\u6027\u80fd\uff0c\u8b93\u67e5\u8a62\u66f4\u9ad8\u6548\uff0c\u52a9\u529b\u696d\u52d9\u589e\u9577\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-74914","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/74914","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=74914"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/74914\/revisions"}],"predecessor-version":[{"id":74921,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/74914\/revisions\/74921"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=74914"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=74914"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=74914"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}