{"id":160643,"date":"2024-11-03T23:48:21","date_gmt":"2024-11-03T15:48:21","guid":{"rendered":"https:\/\/server.hk\/cnblog\/160643\/"},"modified":"2024-11-03T23:48:22","modified_gmt":"2024-11-03T15:48:22","slug":"postgresql%e6%95%99%e7%a8%8bpostgresql-group-by-%e8%aa%9e%e5%8f%a5","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/160643\/","title":{"rendered":"POSTGRESQL\u6559\u7a0bPostgreSQL GROUP BY \u8a9e\u53e5"},"content":{"rendered":"<h1 id=\"postgresql-group-by-%e8%aa%9e%e5%8f%a5%e6%95%99%e7%a8%8b-BVBJZulGgt\">PostgreSQL GROUP BY \u8a9e\u53e5\u6559\u7a0b<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0cPostgreSQL \u662f\u4e00\u500b\u529f\u80fd\u5f37\u5927\u7684\u958b\u6e90\u95dc\u806f\u6578\u64da\u5eab\u7cfb\u7d71\uff0c\u5ee3\u6cdb\u61c9\u7528\u65bc\u5404\u7a2e\u61c9\u7528\u7a0b\u5e8f\u4e2d\u3002\u7576\u6211\u5011\u9700\u8981\u5c0d\u67e5\u8a62\u7d50\u679c\u9032\u884c\u5206\u7d44\u548c\u805a\u5408\u6642\uff0cGROUP BY \u8a9e\u53e5\u4fbf\u6210\u70ba\u4e86\u4e0d\u53ef\u6216\u7f3a\u7684\u5de5\u5177\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e PostgreSQL \u7684 GROUP BY \u8a9e\u53e5\uff0c\u4e26\u63d0\u4f9b\u5be6\u7528\u7684\u7bc4\u4f8b\u548c\u61c9\u7528\u5834\u666f\u3002<\/p>\n<h2 id=\"group-by-%e8%aa%9e%e5%8f%a5%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-BVBJZulGgt\">GROUP BY \u8a9e\u53e5\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>GROUP BY \u8a9e\u53e5\u7528\u65bc\u5c07\u67e5\u8a62\u7d50\u679c\u4e2d\u7684\u6578\u64da\u884c\u5206\u7d44\uff0c\u4e26\u5c0d\u6bcf\u500b\u7d44\u9032\u884c\u805a\u5408\u8a08\u7b97\u3002\u9019\u5728\u9700\u8981\u7d71\u8a08\u6578\u64da\u6642\u7279\u5225\u6709\u7528\uff0c\u4f8b\u5982\u8a08\u7b97\u6bcf\u500b\u985e\u5225\u7684\u7e3d\u92b7\u552e\u984d\u6216\u6bcf\u500b\u90e8\u9580\u7684\u54e1\u5de5\u6578\u91cf\u3002<\/p>\n<h2 id=\"group-by-%e8%aa%9e%e5%8f%a5%e7%9a%84%e8%aa%9e%e6%b3%95-BVBJZulGgt\">GROUP BY \u8a9e\u53e5\u7684\u8a9e\u6cd5<\/h2>\n<pre><code>SELECT column1, aggregate_function(column2)\nFROM table_name\nWHERE condition\nGROUP BY column1;<\/code><\/pre>\n<p>\u5728\u9019\u88e1\uff0c<code>column1<\/code> \u662f\u7528\u65bc\u5206\u7d44\u7684\u5217\uff0c<code>aggregate_function<\/code> \u662f\u805a\u5408\u51fd\u6578\uff0c\u5982 <code>SUM()<\/code>\u3001<code>COUNT()<\/code>\u3001<code>AVG()<\/code> \u7b49\uff0c<code>table_name<\/code> \u662f\u67e5\u8a62\u7684\u6578\u64da\u8868\uff0c<code>condition<\/code> \u662f\u53ef\u9078\u7684\u904e\u6ffe\u689d\u4ef6\u3002<\/p>\n<h2 id=\"%e5%b8%b8%e7%94%a8%e7%9a%84%e8%81%9a%e5%90%88%e5%87%bd%e6%95%b8-BVBJZulGgt\">\u5e38\u7528\u7684\u805a\u5408\u51fd\u6578<\/h2>\n<ul>\n<li><code>COUNT()<\/code>\uff1a\u8a08\u7b97\u884c\u6578\u3002<\/li>\n<li><code>SUM()<\/code>\uff1a\u8a08\u7b97\u6578\u503c\u5217\u7684\u7e3d\u548c\u3002<\/li>\n<li><code>AVG()<\/code>\uff1a\u8a08\u7b97\u6578\u503c\u5217\u7684\u5e73\u5747\u503c\u3002<\/li>\n<li><code>MAX()<\/code>\uff1a\u627e\u51fa\u6578\u503c\u5217\u7684\u6700\u5927\u503c\u3002<\/li>\n<li><code>MIN()<\/code>\uff1a\u627e\u51fa\u6578\u503c\u5217\u7684\u6700\u5c0f\u503c\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%af%84%e4%be%8b%ef%bc%9a%e4%bd%bf%e7%94%a8-group-by-%e8%aa%9e%e5%8f%a5-BVBJZulGgt\">\u7bc4\u4f8b\uff1a\u4f7f\u7528 GROUP BY \u8a9e\u53e5<\/h2>\n<p>\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba <code>sales<\/code> \u7684\u8868\uff0c\u7d50\u69cb\u5982\u4e0b\uff1a<\/p>\n<pre><code>CREATE TABLE sales (\n    id SERIAL PRIMARY KEY,\n    product_name VARCHAR(100),\n    quantity INT,\n    price DECIMAL(10, 2),\n    sale_date DATE\n);<\/code><\/pre>\n<p>\u6211\u5011\u53ef\u4ee5\u4f7f\u7528 GROUP BY \u8a9e\u53e5\u4f86\u8a08\u7b97\u6bcf\u500b\u7522\u54c1\u7684\u7e3d\u92b7\u552e\u91cf\u3002\u4ee5\u4e0b\u662f\u76f8\u61c9\u7684 SQL \u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT product_name, SUM(quantity) AS total_quantity\nFROM sales\nGROUP BY product_name;<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u6bcf\u500b\u7522\u54c1\u7684\u540d\u7a31\u53ca\u5176\u7e3d\u92b7\u552e\u91cf\u3002<\/p>\n<h2 id=\"group-by-%e8%88%87-having-%e5%ad%90%e5%8f%a5-BVBJZulGgt\">GROUP BY \u8207 HAVING \u5b50\u53e5<\/h2>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u6211\u5011\u53ef\u80fd\u9700\u8981\u5c0d\u5206\u7d44\u5f8c\u7684\u7d50\u679c\u9032\u884c\u9032\u4e00\u6b65\u7684\u904e\u6ffe\u3002\u9019\u6642\u53ef\u4ee5\u4f7f\u7528 HAVING \u5b50\u53e5\u3002HAVING \u5b50\u53e5\u901a\u5e38\u8207 GROUP BY \u4e00\u8d77\u4f7f\u7528\uff0c\u7528\u65bc\u904e\u6ffe\u805a\u5408\u7d50\u679c\u3002<\/p>\n<p>\u4f8b\u5982\uff0c\u5982\u679c\u6211\u5011\u53ea\u60f3\u67e5\u770b\u92b7\u552e\u91cf\u8d85\u904e 100 \u7684\u7522\u54c1\uff0c\u53ef\u4ee5\u9019\u6a23\u5beb\uff1a<\/p>\n<pre><code>SELECT product_name, SUM(quantity) AS total_quantity\nFROM sales\nGROUP BY product_name\nHAVING SUM(quantity) &gt; 100;<\/code><\/pre>\n<h2 id=\"%e5%b0%8f%e7%b5%90-BVBJZulGgt\">\u5c0f\u7d50<\/h2>\n<p>PostgreSQL \u7684 GROUP BY \u8a9e\u53e5\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u7528\u6236\u5c0d\u6578\u64da\u9032\u884c\u5206\u7d44\u548c\u805a\u5408\u8a08\u7b97\u3002\u901a\u904e\u7d50\u5408\u4f7f\u7528\u805a\u5408\u51fd\u6578\u548c HAVING \u5b50\u53e5\uff0c\u7528\u6236\u53ef\u4ee5\u9748\u6d3b\u5730\u5206\u6790\u6578\u64da\uff0c\u7372\u53d6\u6709\u50f9\u503c\u7684\u898b\u89e3\u3002\u7121\u8ad6\u662f\u5728\u5546\u696d\u5206\u6790\u3001\u5831\u544a\u751f\u6210\u9084\u662f\u6578\u64da\u6316\u6398\u4e2d\uff0c\u638c\u63e1 GROUP BY \u8a9e\u53e5\u90fd\u662f\u81f3\u95dc\u91cd\u8981\u7684\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\u904b\u884c PostgreSQL \u6578\u64da\u5eab\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u9084\u662f\u5176\u4ed6\u5730\u5340\u7684\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>\u5b78\u7fd2PostgreSQL\u4e2d\u7684GROUP BY\u8a9e\u53e5\uff0c\u638c\u63e1\u5982\u4f55\u5c0d\u6578\u64da\u9032\u884c\u5206\u7d44\u548c\u805a\u5408\uff0c\u63d0\u5347\u6578\u64da\u67e5\u8a62\u6548\u7387\u8207\u5206\u6790\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-160643","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160643","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=160643"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160643\/revisions"}],"predecessor-version":[{"id":160644,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160643\/revisions\/160644"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=160643"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=160643"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=160643"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}