{"id":144055,"date":"2024-11-01T03:48:38","date_gmt":"2024-10-31T19:48:38","guid":{"rendered":"https:\/\/server.hk\/cnblog\/144055\/"},"modified":"2024-11-01T03:48:40","modified_gmt":"2024-10-31T19:48:40","slug":"sql-%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e7%9a%84%e6%99%82%e9%96%93%e6%88%b3%e7%b0%a1%e4%bb%8b%e8%88%87%e6%87%89%e7%94%a8-sql-%e6%95%b8%e6%93%9a%e5%ba%ab%e6%99%82%e9%96%93%e6%88%b3","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/144055\/","title":{"rendered":"SQL \u6578\u64da\u5eab\u4e2d\u7684\u6642\u9593\u6233\u7c21\u4ecb\u8207\u61c9\u7528 (sql \u6578\u64da\u5eab\u6642\u9593\u6233)"},"content":{"rendered":"<h1 id=\"sql-%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e7%9a%84%e6%99%82%e9%96%93%e6%88%b3%e7%b0%a1%e4%bb%8b%e8%88%87%e6%87%89%e7%94%a8-CirssZBivc\">SQL \u6578\u64da\u5eab\u4e2d\u7684\u6642\u9593\u6233\u7c21\u4ecb\u8207\u61c9\u7528<\/h1>\n<p>\u5728\u7576\u4eca\u7684\u6578\u64da\u9a45\u52d5\u4e16\u754c\u4e2d\uff0c\u6642\u9593\u6233\uff08Timestamp\uff09\u5728\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\u626e\u6f14\u8457\u81f3\u95dc\u91cd\u8981\u7684\u89d2\u8272\u3002\u7121\u8ad6\u662f\u7528\u65bc\u8a18\u9304\u6578\u64da\u7684\u5275\u5efa\u6642\u9593\u3001\u66f4\u65b0\u6642\u9593\uff0c\u9084\u662f\u7528\u65bc\u6642\u9593\u5e8f\u5217\u6578\u64da\u7684\u5206\u6790\uff0c\u6642\u9593\u6233\u90fd\u80fd\u63d0\u4f9b\u95dc\u9375\u7684\u6642\u9593\u4e0a\u4e0b\u6587\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e SQL \u6578\u64da\u5eab\u4e2d\u7684\u6642\u9593\u6233\u6982\u5ff5\u53ca\u5176\u61c9\u7528\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e6%99%82%e9%96%93%e6%88%b3%ef%bc%9f-CirssZBivc\">\u4ec0\u9ebc\u662f\u6642\u9593\u6233\uff1f<\/h2>\n<p>\u6642\u9593\u6233\u662f\u4e00\u7a2e\u6578\u64da\u985e\u578b\uff0c\u7528\u65bc\u8868\u793a\u7279\u5b9a\u7684\u6642\u9593\u9ede\u3002\u5b83\u901a\u5e38\u4ee5\u65e5\u671f\u548c\u6642\u9593\u7684\u5f62\u5f0f\u5b58\u5132\uff0c\u4e26\u4e14\u53ef\u4ee5\u7cbe\u78ba\u5230\u79d2\u6216\u6beb\u79d2\u3002SQL \u6578\u64da\u5eab\u4e2d\u5e38\u898b\u7684\u6642\u9593\u6233\u985e\u578b\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><strong>DATETIME<\/strong>\uff1a\u8868\u793a\u65e5\u671f\u548c\u6642\u9593\uff0c\u7bc4\u570d\u5f9e 1753 \u5e74\u5230 9999 \u5e74\uff0c\u7cbe\u5ea6\u5230\u79d2\u3002<\/li>\n<li><strong>TIMESTAMP<\/strong>\uff1a\u8207 DATETIME \u985e\u4f3c\uff0c\u4f46\u901a\u5e38\u7528\u65bc\u8a18\u9304\u4e8b\u4ef6\u7684\u6642\u9593\uff0c\u4e26\u4e14\u6703\u96a8\u8457\u6642\u5340\u7684\u8b8a\u5316\u800c\u8b8a\u5316\u3002<\/li>\n<li><strong>DATE<\/strong>\uff1a\u50c5\u8868\u793a\u65e5\u671f\uff0c\u4e0d\u5305\u542b\u6642\u9593\u3002<\/li>\n<li><strong>TIME<\/strong>\uff1a\u50c5\u8868\u793a\u6642\u9593\uff0c\u4e0d\u5305\u542b\u65e5\u671f\u3002<\/li>\n<\/ul>\n<h2 id=\"%e6%99%82%e9%96%93%e6%88%b3%e7%9a%84%e6%87%89%e7%94%a8-CirssZBivc\">\u6642\u9593\u6233\u7684\u61c9\u7528<\/h2>\n<p>\u6642\u9593\u6233\u5728 SQL \u6578\u64da\u5eab\u4e2d\u7684\u61c9\u7528\u975e\u5e38\u5ee3\u6cdb\uff0c\u4ee5\u4e0b\u662f\u5e7e\u500b\u4e3b\u8981\u7684\u61c9\u7528\u5834\u666f\uff1a<\/p>\n<h3 id=\"1-%e6%95%b8%e6%93%9a%e7%89%88%e6%9c%ac%e6%8e%a7%e5%88%b6-CirssZBivc\">1. \u6578\u64da\u7248\u672c\u63a7\u5236<\/h3>\n<p>\u5728\u8a31\u591a\u61c9\u7528\u4e2d\uff0c\u8ddf\u8e2a\u6578\u64da\u7684\u8b8a\u66f4\u6b77\u53f2\u662f\u975e\u5e38\u91cd\u8981\u7684\u3002\u901a\u904e\u5728\u6578\u64da\u8868\u4e2d\u6dfb\u52a0\u6642\u9593\u6233\u5217\uff0c\u53ef\u4ee5\u8a18\u9304\u6bcf\u6b21\u6578\u64da\u66f4\u65b0\u7684\u6642\u9593\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>CREATE TABLE users (\n    id INT PRIMARY KEY,\n    name VARCHAR(100),\n    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,\n    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP\n);<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c<code>created_at<\/code> \u5217\u8a18\u9304\u7528\u6236\u5275\u5efa\u7684\u6642\u9593\uff0c\u800c <code>updated_at<\/code> \u5217\u5247\u5728\u6bcf\u6b21\u66f4\u65b0\u6642\u81ea\u52d5\u66f4\u65b0\u70ba\u7576\u524d\u6642\u9593\u3002<\/p>\n<h3 id=\"2-%e5%af%a6%e6%99%82%e6%95%b8%e6%93%9a%e5%88%86%e6%9e%90-CirssZBivc\">2. \u5be6\u6642\u6578\u64da\u5206\u6790<\/h3>\n<p>\u5728\u8a31\u591a\u696d\u52d9\u5834\u666f\u4e2d\uff0c\u5be6\u6642\u6578\u64da\u5206\u6790\u662f\u5fc5\u4e0d\u53ef\u5c11\u7684\u3002\u6642\u9593\u6233\u53ef\u4ee5\u5e6b\u52a9\u5206\u6790\u6578\u64da\u96a8\u6642\u9593\u7684\u8b8a\u5316\u3002\u4f8b\u5982\uff0c\u5c0d\u65bc\u4e00\u500b\u96fb\u5546\u5e73\u53f0\uff0c\u53ef\u4ee5\u4f7f\u7528\u6642\u9593\u6233\u4f86\u5206\u6790\u92b7\u552e\u8da8\u52e2\uff1a<\/p>\n<pre><code>SELECT DATE(created_at) AS sale_date, COUNT(*) AS total_sales\nFROM orders\nGROUP BY sale_date\nORDER BY sale_date;<\/code><\/pre>\n<p>\u9019\u6bb5 SQL \u67e5\u8a62\u5c07\u8fd4\u56de\u6bcf\u5929\u7684\u92b7\u552e\u7e3d\u6578\uff0c\u5e6b\u52a9\u5546\u5bb6\u4e86\u89e3\u92b7\u552e\u8da8\u52e2\u3002<\/p>\n<h3 id=\"3-%e4%ba%8b%e4%bb%b6%e8%a8%98%e9%8c%84-CirssZBivc\">3. \u4e8b\u4ef6\u8a18\u9304<\/h3>\n<p>\u8a31\u591a\u61c9\u7528\u9700\u8981\u8a18\u9304\u7528\u6236\u884c\u70ba\u6216\u7cfb\u7d71\u4e8b\u4ef6\u3002\u6642\u9593\u6233\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u8ffd\u8e64\u4e8b\u4ef6\u7684\u767c\u751f\u6642\u9593\uff0c\u5f9e\u800c\u9032\u884c\u6545\u969c\u6392\u67e5\u6216\u6027\u80fd\u5206\u6790\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>CREATE TABLE logs (\n    id INT PRIMARY KEY AUTO_INCREMENT,\n    event VARCHAR(255),\n    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n);<\/code><\/pre>\n<p>\u9019\u6a23\u7684\u8a2d\u8a08\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u8a18\u9304\u6bcf\u500b\u4e8b\u4ef6\u7684\u767c\u751f\u6642\u9593\uff0c\u4fbf\u65bc\u5f8c\u7e8c\u7684\u5206\u6790\u548c\u8abf\u8a66\u3002<\/p>\n<h2 id=\"%e7%b5%90%e8%ab%96-CirssZBivc\">\u7d50\u8ad6<\/h2>\n<p>\u6642\u9593\u6233\u5728 SQL \u6578\u64da\u5eab\u4e2d\u662f\u4e00\u500b\u4e0d\u53ef\u6216\u7f3a\u7684\u529f\u80fd\uff0c\u7121\u8ad6\u662f\u5728\u6578\u64da\u7248\u672c\u63a7\u5236\u3001\u5be6\u6642\u6578\u64da\u5206\u6790\u9084\u662f\u4e8b\u4ef6\u8a18\u9304\u65b9\u9762\uff0c\u90fd\u767c\u63ee\u8457\u91cd\u8981\u4f5c\u7528\u3002\u6b63\u78ba\u4f7f\u7528\u6642\u9593\u6233\u4e0d\u50c5\u80fd\u63d0\u9ad8\u6578\u64da\u7684\u53ef\u8ffd\u6eaf\u6027\uff0c\u9084\u80fd\u589e\u5f37\u6578\u64da\u5206\u6790\u7684\u6df1\u5ea6\u548c\u5ee3\u5ea6\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4f86\u652f\u6301\u60a8\u7684\u6578\u64da\u5eab\u61c9\u7528\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u4e0d\u540c\u9700\u6c42\u7684\u5ba2\u6236\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u9084\u662f\u5176\u4ed6\u670d\u52d9\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u53ef\u9760\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3SQL\u6578\u64da\u5eab\u4e2d\u7684\u6642\u9593\u6233\u6982\u5ff5\u53ca\u5176\u61c9\u7528\uff0c\u63d0\u5347\u6578\u64da\u7ba1\u7406\u6548\u7387\uff0c\u78ba\u4fdd\u6578\u64da\u6e96\u78ba\u6027\u8207\u4e00\u81f4\u6027\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-144055","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/144055","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=144055"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/144055\/revisions"}],"predecessor-version":[{"id":144056,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/144055\/revisions\/144056"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=144055"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=144055"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=144055"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}