{"id":168533,"date":"2024-11-06T13:10:24","date_gmt":"2024-11-06T05:10:24","guid":{"rendered":"https:\/\/server.hk\/cnblog\/168533\/"},"modified":"2024-11-06T13:10:25","modified_gmt":"2024-11-06T05:10:25","slug":"sql-%e4%b8%ad%e7%9a%84%e6%99%82%e9%96%93%e5%87%bd%e6%95%b8","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/168533\/","title":{"rendered":"SQL \u4e2d\u7684\u6642\u9593\u51fd\u6578"},"content":{"rendered":"<h1 id=\"sql-%e4%b8%ad%e7%9a%84%e6%99%82%e9%96%93%e5%87%bd%e6%95%b8-CqxeBrnaEZ\">SQL \u4e2d\u7684\u6642\u9593\u51fd\u6578<\/h1>\n<p>\u5728\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u6642\u9593\u548c\u65e5\u671f\u7684\u8655\u7406\u662f\u975e\u5e38\u91cd\u8981\u7684\u3002SQL \u63d0\u4f9b\u4e86\u4e00\u7cfb\u5217\u7684\u6642\u9593\u51fd\u6578\uff0c\u9019\u4e9b\u51fd\u6578\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u548c\u6578\u64da\u5206\u6790\u5e2b\u9032\u884c\u6642\u9593\u76f8\u95dc\u7684\u8a08\u7b97\u548c\u67e5\u8a62\u3002\u672c\u6587\u5c07\u4ecb\u7d39 SQL \u4e2d\u5e38\u7528\u7684\u6642\u9593\u51fd\u6578\u53ca\u5176\u61c9\u7528\u3002<\/p>\n<h2 id=\"1-%e7%95%b6%e5%89%8d%e6%99%82%e9%96%93%e5%87%bd%e6%95%b8-CqxeBrnaEZ\">1. \u7576\u524d\u6642\u9593\u51fd\u6578<\/h2>\n<p>\u5728 SQL \u4e2d\uff0c\u7372\u53d6\u7576\u524d\u6642\u9593\u7684\u51fd\u6578\u4e3b\u8981\u6709\u4ee5\u4e0b\u5e7e\u500b\uff1a<\/p>\n<ul>\n<li><code>NOW()<\/code>\uff1a\u8fd4\u56de\u7576\u524d\u7684\u65e5\u671f\u548c\u6642\u9593\u3002<\/li>\n<li><code>CURRENT_DATE()<\/code>\uff1a\u8fd4\u56de\u7576\u524d\u7684\u65e5\u671f\u3002<\/li>\n<li><code>CURRENT_TIME()<\/code>\uff1a\u8fd4\u56de\u7576\u524d\u7684\u6642\u9593\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u4f7f\u7528 <code>NOW()<\/code> \u51fd\u6578\u53ef\u4ee5\u9019\u6a23\u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT NOW();<\/code><\/pre>\n<h2 id=\"2-%e6%97%a5%e6%9c%9f%e5%92%8c%e6%99%82%e9%96%93%e7%9a%84%e5%8a%a0%e6%b8%9b-CqxeBrnaEZ\">2. \u65e5\u671f\u548c\u6642\u9593\u7684\u52a0\u6e1b<\/h2>\n<p>SQL \u63d0\u4f9b\u4e86\u591a\u7a2e\u65b9\u6cd5\u4f86\u5c0d\u65e5\u671f\u548c\u6642\u9593\u9032\u884c\u52a0\u6e1b\u64cd\u4f5c\u3002\u5e38\u7528\u7684\u51fd\u6578\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><code>DATE_ADD(date, INTERVAL expr unit)<\/code>\uff1a\u5c07\u6307\u5b9a\u7684\u6642\u9593\u9593\u9694\u52a0\u5230\u65e5\u671f\u4e0a\u3002<\/li>\n<li><code>DATE_SUB(date, INTERVAL expr unit)<\/code>\uff1a\u5f9e\u65e5\u671f\u4e2d\u6e1b\u53bb\u6307\u5b9a\u7684\u6642\u9593\u9593\u9694\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u82e5\u8981\u5728\u7576\u524d\u65e5\u671f\u4e0a\u52a0\u4e0a 10 \u5929\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT DATE_ADD(CURRENT_DATE(), INTERVAL 10 DAY);<\/code><\/pre>\n<h2 id=\"3-%e6%97%a5%e6%9c%9f%e6%a0%bc%e5%bc%8f%e5%8c%96-CqxeBrnaEZ\">3. \u65e5\u671f\u683c\u5f0f\u5316<\/h2>\n<p>\u5728 SQL \u4e2d\uff0c\u683c\u5f0f\u5316\u65e5\u671f\u7684\u51fd\u6578\u4e3b\u8981\u662f <code>DATE_FORMAT(date, format)<\/code>\u3002\u9019\u500b\u51fd\u6578\u53ef\u4ee5\u5c07\u65e5\u671f\u8f49\u63db\u70ba\u6307\u5b9a\u7684\u683c\u5f0f\u3002\u5e38\u898b\u7684\u683c\u5f0f\u5316\u7b26\u865f\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><code>%Y<\/code>\uff1a\u56db\u4f4d\u6578\u7684\u5e74\u4efd<\/li>\n<li><code>%m<\/code>\uff1a\u5169\u4f4d\u6578\u7684\u6708\u4efd<\/li>\n<li><code>%d<\/code>\uff1a\u5169\u4f4d\u6578\u7684\u65e5\u671f<\/li>\n<li><code>%H<\/code>\uff1a24\u5c0f\u6642\u5236\u7684\u6642<\/li>\n<li><code>%i<\/code>\uff1a\u5206\u9418<\/li>\n<li><code>%s<\/code>\uff1a\u79d2<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u5c07\u7576\u524d\u65e5\u671f\u683c\u5f0f\u5316\u70ba &#8220;YYYY-MM-DD&#8221; \u7684\u683c\u5f0f\uff0c\u53ef\u4ee5\u9019\u6a23\u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT DATE_FORMAT(NOW(), '%Y-%m-%d');<\/code><\/pre>\n<h2 id=\"4-%e6%97%a5%e6%9c%9f%e6%af%94%e8%bc%83-CqxeBrnaEZ\">4. \u65e5\u671f\u6bd4\u8f03<\/h2>\n<p>\u5728 SQL \u4e2d\uff0c\u65e5\u671f\u6bd4\u8f03\u662f\u5e38\u898b\u7684\u64cd\u4f5c\u3002\u53ef\u4ee5\u4f7f\u7528\u6a19\u6e96\u7684\u6bd4\u8f03\u904b\u7b97\u7b26\uff08\u5982 <code>=<\/code>, <code>&gt;<\/code>, <code>&lt;<\/code> \u7b49\uff09\u4f86\u6bd4\u8f03\u65e5\u671f\u3002\u4f8b\u5982\uff0c\u67e5\u8a62\u67d0\u500b\u65e5\u671f\u4e4b\u524d\u7684\u6240\u6709\u8a18\u9304\uff1a<\/p>\n<pre><code>SELECT * FROM orders WHERE order_date &lt; '2023-01-01';<\/code><\/pre>\n<h2 id=\"5-%e5%85%b6%e4%bb%96%e6%9c%89%e7%94%a8%e7%9a%84%e6%99%82%e9%96%93%e5%87%bd%e6%95%b8-CqxeBrnaEZ\">5. \u5176\u4ed6\u6709\u7528\u7684\u6642\u9593\u51fd\u6578<\/h2>\n<p>\u9664\u4e86\u4e0a\u8ff0\u51fd\u6578\uff0cSQL \u9084\u63d0\u4f9b\u4e86\u4e00\u4e9b\u5176\u4ed6\u6709\u7528\u7684\u6642\u9593\u51fd\u6578\uff0c\u4f8b\u5982\uff1a<\/p>\n<ul>\n<li><code>DATEDIFF(date1, date2)<\/code>\uff1a\u8a08\u7b97\u5169\u500b\u65e5\u671f\u4e4b\u9593\u7684\u5929\u6578\u3002<\/li>\n<li><code>TIMESTAMPDIFF(unit, datetime1, datetime2)<\/code>\uff1a\u8a08\u7b97\u5169\u500b\u65e5\u671f\u6642\u9593\u4e4b\u9593\u7684\u5dee\u7570\uff0c\u4e26\u4ee5\u6307\u5b9a\u7684\u55ae\u4f4d\u8fd4\u56de\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u8a08\u7b97\u5169\u500b\u65e5\u671f\u4e4b\u9593\u7684\u5929\u6578\uff1a<\/p>\n<pre><code>SELECT DATEDIFF('2023-01-01', '2022-12-25');<\/code><\/pre>\n<h2 id=\"%e7%b8%bd%e7%b5%90-CqxeBrnaEZ\">\u7e3d\u7d50<\/h2>\n<p>SQL \u4e2d\u7684\u6642\u9593\u51fd\u6578\u70ba\u958b\u767c\u8005\u63d0\u4f9b\u4e86\u5f37\u5927\u7684\u5de5\u5177\u4f86\u8655\u7406\u548c\u5206\u6790\u6642\u9593\u6578\u64da\u3002\u7121\u8ad6\u662f\u7372\u53d6\u7576\u524d\u6642\u9593\u3001\u9032\u884c\u65e5\u671f\u8a08\u7b97\uff0c\u9084\u662f\u683c\u5f0f\u5316\u548c\u6bd4\u8f03\u65e5\u671f\uff0c\u9019\u4e9b\u51fd\u6578\u90fd\u80fd\u5920\u6709\u6548\u5730\u652f\u6301\u5404\u7a2e\u9700\u6c42\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u7ba1\u7406\u6642\u9593\u6578\u64da\u7684\u61c9\u7528\u4f86\u8aaa\uff0c\u719f\u6089\u9019\u4e9b\u51fd\u6578\u662f\u975e\u5e38\u91cd\u8981\u7684\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u7a69\u5b9a\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/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\u500b\u4eba\u9805\u76ee\u9084\u662f\u4f01\u696d\u61c9\u7528\uff0c\u6211\u5011\u7684 <a href=\"https:\/\/server.hk\">\u4e91\u670d\u52a1\u5668<\/a> \u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u53ef\u9760\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22 SQL \u4e2d\u7684\u6642\u9593\u51fd\u6578\uff0c\u5b78\u7fd2\u5982\u4f55\u8655\u7406\u65e5\u671f\u548c\u6642\u9593\u6578\u64da\uff0c\u63d0\u5347\u6578\u64da\u67e5\u8a62\u548c\u5206\u6790\u7684\u6548\u7387\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-168533","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168533","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=168533"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168533\/revisions"}],"predecessor-version":[{"id":168534,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168533\/revisions\/168534"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=168533"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=168533"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=168533"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}