{"id":153725,"date":"2024-11-02T09:50:18","date_gmt":"2024-11-02T01:50:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/153725\/"},"modified":"2024-11-02T09:50:19","modified_gmt":"2024-11-02T01:50:19","slug":"%e5%b8%b6%e6%82%a8%e4%ba%86%e8%a7%a3mysql%e8%ae%8a%e9%87%8f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/153725\/","title":{"rendered":"\u5e36\u60a8\u4e86\u89e3mysql\u8b8a\u91cf"},"content":{"rendered":"<h1 id=\"%e5%b8%b6%e6%82%a8%e4%ba%86%e8%a7%a3-mysql-%e8%ae%8a%e9%87%8f-qdoZuFdciI\">\u5e36\u60a8\u4e86\u89e3 MySQL \u8b8a\u91cf<\/h1>\n<p>MySQL \u662f\u4e00\u500b\u5ee3\u6cdb\u4f7f\u7528\u7684\u958b\u6e90\u95dc\u806f\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u8a31\u591a\u958b\u767c\u8005\u548c\u4f01\u696d\u4f9d\u8cf4\u5b83\u4f86\u5b58\u5132\u548c\u7ba1\u7406\u6578\u64da\u3002\u5728 MySQL \u4e2d\uff0c\u8b8a\u91cf\u662f\u4e00\u500b\u91cd\u8981\u7684\u6982\u5ff5\uff0c\u80fd\u5920\u5e6b\u52a9\u7528\u6236\u63a7\u5236\u6578\u64da\u5eab\u7684\u884c\u70ba\u548c\u6027\u80fd\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e MySQL \u8b8a\u91cf\u7684\u985e\u578b\u3001\u4f5c\u7528\u53ca\u5176\u4f7f\u7528\u65b9\u6cd5\u3002<\/p>\n<h2 id=\"mysql-%e8%ae%8a%e9%87%8f%e7%9a%84%e9%a1%9e%e5%9e%8b-qdoZuFdciI\">MySQL \u8b8a\u91cf\u7684\u985e\u578b<\/h2>\n<p>MySQL \u8b8a\u91cf\u4e3b\u8981\u5206\u70ba\u4e09\u7a2e\u985e\u578b\uff1a\u7cfb\u7d71\u8b8a\u91cf\u3001\u7528\u6236\u8b8a\u91cf\u548c\u5c40\u90e8\u8b8a\u91cf\u3002<\/p>\n<ul>\n<li><strong>\u7cfb\u7d71\u8b8a\u91cf\uff1a<\/strong>\u9019\u4e9b\u8b8a\u91cf\u662f MySQL \u4f3a\u670d\u5668\u7684\u914d\u7f6e\u9078\u9805\uff0c\u5f71\u97ff\u4f3a\u670d\u5668\u7684\u884c\u70ba\u548c\u6027\u80fd\u3002\u7cfb\u7d71\u8b8a\u91cf\u53ef\u4ee5\u5728\u4f3a\u670d\u5668\u555f\u52d5\u6642\u8a2d\u7f6e\uff0c\u4e26\u4e14\u53ef\u4ee5\u5728\u904b\u884c\u6642\u9032\u884c\u8abf\u6574\u3002\u7528\u6236\u53ef\u4ee5\u4f7f\u7528 <code>SHOW VARIABLES;<\/code> \u547d\u4ee4\u4f86\u67e5\u770b\u7576\u524d\u7684\u7cfb\u7d71\u8b8a\u91cf\u3002<\/li>\n<li><strong>\u7528\u6236\u8b8a\u91cf\uff1a<\/strong>\u9019\u4e9b\u8b8a\u91cf\u662f\u7528\u6236\u5728\u6703\u8a71\u4e2d\u5b9a\u7fa9\u7684\uff0c\u901a\u5e38\u7528\u65bc\u5b58\u5132\u81e8\u6642\u6578\u64da\u3002\u7528\u6236\u8b8a\u91cf\u7684\u547d\u540d\u4ee5 @ \u7b26\u865f\u958b\u982d\uff0c\u4f8b\u5982 <code>@my_variable<\/code>\u3002\u7528\u6236\u8b8a\u91cf\u7684\u4f5c\u7528\u7bc4\u570d\u50c5\u9650\u65bc\u7576\u524d\u6703\u8a71\u3002<\/li>\n<li><strong>\u5c40\u90e8\u8b8a\u91cf\uff1a<\/strong>\u9019\u4e9b\u8b8a\u91cf\u662f\u5728\u5b58\u5132\u904e\u7a0b\u6216\u51fd\u6578\u4e2d\u5b9a\u7fa9\u7684\uff0c\u50c5\u5728\u8a72\u904e\u7a0b\u6216\u51fd\u6578\u7684\u7bc4\u570d\u5167\u6709\u6548\u3002\u5c40\u90e8\u8b8a\u91cf\u7684\u5b9a\u7fa9\u4f7f\u7528 <code>DECLARE<\/code> \u8a9e\u53e5\uff0c\u4f8b\u5982 <code>DECLARE my_var INT;<\/code>\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b3%bb%e7%b5%b1%e8%ae%8a%e9%87%8f%e7%9a%84%e4%bd%bf%e7%94%a8-qdoZuFdciI\">\u7cfb\u7d71\u8b8a\u91cf\u7684\u4f7f\u7528<\/h2>\n<p>\u7cfb\u7d71\u8b8a\u91cf\u53ef\u4ee5\u5f71\u97ff MySQL \u7684\u591a\u500b\u65b9\u9762\uff0c\u4f8b\u5982\u9023\u63a5\u6578\u91cf\u3001\u7de9\u885d\u5340\u5927\u5c0f\u548c\u67e5\u8a62\u7de9\u5b58\u7b49\u3002\u7528\u6236\u53ef\u4ee5\u4f7f\u7528 <code>SET GLOBAL<\/code> \u6216 <code>SET SESSION<\/code> \u547d\u4ee4\u4f86\u4fee\u6539\u9019\u4e9b\u8b8a\u91cf\u3002<\/p>\n<pre><code>SET GLOBAL max_connections = 200;<\/code><\/pre>\n<p>\u4e0a\u8ff0\u547d\u4ee4\u5c07\u6700\u5927\u9023\u63a5\u6578\u8a2d\u7f6e\u70ba 200\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u4fee\u6539\u7cfb\u7d71\u8b8a\u91cf\u53ef\u80fd\u6703\u5f71\u97ff\u5230\u6240\u6709\u7528\u6236\uff0c\u56e0\u6b64\u5728\u9032\u884c\u66f4\u6539\u6642\u61c9\u8b39\u614e\u8003\u616e\u3002<\/p>\n<h2 id=\"%e7%94%a8%e6%88%b6%e8%ae%8a%e9%87%8f%e7%9a%84%e4%bd%bf%e7%94%a8-qdoZuFdciI\">\u7528\u6236\u8b8a\u91cf\u7684\u4f7f\u7528<\/h2>\n<p>\u7528\u6236\u8b8a\u91cf\u7684\u4f7f\u7528\u975e\u5e38\u9748\u6d3b\uff0c\u901a\u5e38\u7528\u65bc\u5728\u67e5\u8a62\u4e2d\u5b58\u5132\u4e2d\u9593\u7d50\u679c\u3002\u4f8b\u5982\uff0c\u60a8\u53ef\u4ee5\u5728\u4e00\u500b\u67e5\u8a62\u4e2d\u8a08\u7b97\u67d0\u500b\u503c\uff0c\u7136\u5f8c\u5728\u5f8c\u7e8c\u7684\u67e5\u8a62\u4e2d\u4f7f\u7528\u8a72\u503c\uff1a<\/p>\n<pre><code>SET @total_sales = (SELECT SUM(sales) FROM orders);\nSELECT @total_sales;<\/code><\/pre>\n<p>\u9019\u6a23\uff0c\u60a8\u5c31\u53ef\u4ee5\u5728\u4e0d\u540c\u7684\u67e5\u8a62\u4e2d\u91cd\u8907\u4f7f\u7528\u8a08\u7b97\u51fa\u7684\u7e3d\u92b7\u552e\u984d\uff0c\u800c\u4e0d\u9700\u8981\u6bcf\u6b21\u90fd\u91cd\u65b0\u8a08\u7b97\u3002<\/p>\n<h2 id=\"%e5%b1%80%e9%83%a8%e8%ae%8a%e9%87%8f%e7%9a%84%e4%bd%bf%e7%94%a8-qdoZuFdciI\">\u5c40\u90e8\u8b8a\u91cf\u7684\u4f7f\u7528<\/h2>\n<p>\u5c40\u90e8\u8b8a\u91cf\u901a\u5e38\u5728\u5b58\u5132\u904e\u7a0b\u4e2d\u4f7f\u7528\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u7ba1\u7406\u8907\u96dc\u7684\u908f\u8f2f\u3002\u4f8b\u5982\uff0c\u60a8\u53ef\u4ee5\u5728\u5b58\u5132\u904e\u7a0b\u4e2d\u5b9a\u7fa9\u4e00\u500b\u5c40\u90e8\u8b8a\u91cf\u4f86\u8a08\u7b97\u67d0\u500b\u503c\uff1a<\/p>\n<pre><code>CREATE PROCEDURE calculate_discount()\nBEGIN\n    DECLARE discount_rate DECIMAL(5,2);\n    SET discount_rate = 0.10;\n    -- \u5176\u4ed6\u908f\u8f2f\nEND;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c<code>discount_rate<\/code> \u8b8a\u91cf\u50c5\u5728 <code>calculate_discount<\/code> \u5b58\u5132\u904e\u7a0b\u5167\u6709\u6548\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-qdoZuFdciI\">\u7e3d\u7d50<\/h2>\n<p>MySQL \u8b8a\u91cf\u662f\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\u4e0d\u53ef\u6216\u7f3a\u7684\u4e00\u90e8\u5206\uff0c\u7121\u8ad6\u662f\u7cfb\u7d71\u8b8a\u91cf\u3001\u7528\u6236\u8b8a\u91cf\u9084\u662f\u5c40\u90e8\u8b8a\u91cf\uff0c\u90fd\u80fd\u5920\u5e6b\u52a9\u7528\u6236\u66f4\u6709\u6548\u5730\u7ba1\u7406\u6578\u64da\u548c\u512a\u5316\u6027\u80fd\u3002\u4e86\u89e3\u9019\u4e9b\u8b8a\u91cf\u7684\u4f7f\u7528\u65b9\u6cd5\uff0c\u5c07\u6709\u52a9\u65bc\u958b\u767c\u8005\u5728\u65e5\u5e38\u5de5\u4f5c\u4e2d\u63d0\u9ad8\u6548\u7387\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2f VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u4e0d\u540c\u7528\u6236\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f\u6578\u64da\u5eab\u7ba1\u7406\u9084\u662f\u7db2\u7ad9\u6258\u7ba1\uff0c\u6211\u5011\u7684 <a href=\"https:\/\/server.hk\">\u4f3a\u670d\u5668<\/a> \u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6df1\u5165\u4e86\u89e3MySQL\u8b8a\u91cf\u7684\u529f\u80fd\u8207\u61c9\u7528\uff0c\u638c\u63e1\u6578\u64da\u5eab\u7ba1\u7406\u7684\u95dc\u9375\u6280\u5de7\uff0c\u63d0\u5347\u60a8\u7684\u6578\u64da\u8655\u7406\u80fd\u529b\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-153725","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/153725","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=153725"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/153725\/revisions"}],"predecessor-version":[{"id":153726,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/153725\/revisions\/153726"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=153725"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=153725"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=153725"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}