{"id":199613,"date":"2025-05-06T08:31:06","date_gmt":"2025-05-06T00:31:06","guid":{"rendered":"https:\/\/server.hk\/cnblog\/199613\/"},"modified":"2025-05-06T08:31:06","modified_gmt":"2025-05-06T00:31:06","slug":"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8sql%e8%af%ad%e5%8f%a5%e5%9c%a8mysql%e4%b8%ad%e8%bf%9b%e8%a1%8c%e6%95%b0%e6%8d%ae%e8%81%9a%e5%90%88%e5%92%8c%e7%bb%9f%e8%ae%a1%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/199613\/","title":{"rendered":"\u5982\u4f55\u4f7f\u7528SQL\u8bed\u53e5\u5728MySQL\u4e2d\u8fdb\u884c\u6570\u636e\u805a\u5408\u548c\u7edf\u8ba1\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u5982\u4f55\u4f7f\u7528SQL\u8bed\u53e5\u5728MySQL\u4e2d\u8fdb\u884c\u6570\u636e\u805a\u5408\u548c\u7edf\u8ba1\uff1f<\/h1>\n<p>\u4ece\u73b0\u5728\u5f00\u59cb\uff0c\u52aa\u529b\u5b66\u4e60\u5427\uff01\u672c\u6587\u4e3b\u8981\u8bb2\u89e3\u4e86\u7b49\u7b49\u76f8\u5173\u77e5\u8bc6\u70b9\uff0c\u6211\u4f1a\u5728\u4e3b\u673a\u5b9d\u8d1d\u4e2d\u6301\u7eed\u66f4\u65b0\u76f8\u5173\u7684\u7cfb\u5217\u6587\u7ae0\uff0c\u6b22\u8fce\u5927\u5bb6\u5173\u6ce8\u5e76\u79ef\u6781\u7559\u8a00\u5efa\u8bae\u3002\u4e0b\u9762\u5c31\u5148\u4e00\u8d77\u6765\u770b\u4e00\u4e0b\u672c\u7bc7\u6b63\u6587\u5185\u5bb9\u5427\uff0c\u5e0c\u671b\u80fd\u5e2e\u5230\u4f60\uff01<\/p>\n<p>\u5982\u4f55\u4f7f\u7528SQL\u8bed\u53e5\u5728MySQL\u4e2d\u8fdb\u884c\u6570\u636e\u805a\u5408\u548c\u7edf\u8ba1\uff1f<\/p>\n<p>\u5728\u8fdb\u884c\u6570\u636e\u5206\u6790\u548c\u7edf\u8ba1\u65f6\uff0c\u6570\u636e\u805a\u5408\u548c\u7edf\u8ba1\u662f\u975e\u5e38\u91cd\u8981\u7684\u6b65\u9aa4\u3002MySQL\u4f5c\u4e3a\u4e00\u4e2a\u529f\u80fd\u5f3a\u5927\u7684\u5173\u7cfb\u578b\u6570\u636e\u5e93\u7ba1\u7406\u7cfb\u7edf\uff0c\u63d0\u4f9b\u4e86\u4e30\u5bcc\u7684\u805a\u5408\u548c\u7edf\u8ba1\u51fd\u6570\uff0c\u53ef\u4ee5\u5f88\u65b9\u4fbf\u5730\u8fdb\u884c\u6570\u636e\u805a\u5408\u548c\u7edf\u8ba1\u64cd\u4f5c\u3002<\/p>\n<p>\u672c\u6587\u5c06\u4ecb\u7ecd\u4f7f\u7528SQL\u8bed\u53e5\u5728MySQL\u4e2d\u8fdb\u884c\u6570\u636e\u805a\u5408\u548c\u7edf\u8ba1\u7684\u65b9\u6cd5\uff0c\u5e76\u63d0\u4f9b\u5177\u4f53\u7684\u4ee3\u7801\u793a\u4f8b\u3002<\/p>\n<p>\u4e00\u3001\u4f7f\u7528COUNT\u51fd\u6570\u8fdb\u884c\u8ba1\u6570<\/p>\n<p>COUNT\u51fd\u6570\u662f\u6700\u5e38\u7528\u7684\u805a\u5408\u51fd\u6570\u4e4b\u4e00\uff0c\u7528\u4e8e\u7edf\u8ba1\u6307\u5b9a\u5217\u6216\u8868\u4e2d\u7684\u8bb0\u5f55\u6570\u91cf\u3002<\/p>\n<p>\u793a\u4f8b1\uff1a\u7edf\u8ba1\u8868\u4e2d\u7684\u8bb0\u5f55\u6570\u91cf<\/p>\n<pre>SELECT COUNT(*) AS count FROM table_name;<\/pre>\n<p>\u793a\u4f8b2\uff1a\u7edf\u8ba1\u67d0\u4e2a\u5217\u7684\u975e\u7a7a\u503c\u6570\u91cf<\/p>\n<pre>SELECT COUNT(column_name) AS count FROM table_name;<\/pre>\n<p>\u4e8c\u3001\u4f7f\u7528SUM\u51fd\u6570\u8fdb\u884c\u6c42\u548c<\/p>\n<p>SUM\u51fd\u6570\u7528\u4e8e\u8ba1\u7b97\u6307\u5b9a\u5217\u6216\u8868\u4e2d\u6570\u503c\u578b\u5b57\u6bb5\u7684\u603b\u548c\u3002<\/p>\n<p>\u793a\u4f8b3\uff1a\u8ba1\u7b97\u67d0\u4e2a\u5217\u7684\u603b\u548c<\/p>\n<pre>SELECT SUM(column_name) AS sum FROM table_name;<\/pre>\n<p>\u4e09\u3001\u4f7f\u7528AVG\u51fd\u6570\u8fdb\u884c\u5e73\u5747\u503c\u8ba1\u7b97<\/p>\n<p>AVG\u51fd\u6570\u7528\u4e8e\u8ba1\u7b97\u6307\u5b9a\u5217\u6216\u8868\u4e2d\u6570\u503c\u578b\u5b57\u6bb5\u7684\u5e73\u5747\u503c\u3002<\/p>\n<p>\u793a\u4f8b4\uff1a\u8ba1\u7b97\u67d0\u4e2a\u5217\u7684\u5e73\u5747\u503c<\/p>\n<pre>SELECT AVG(column_name) AS average FROM table_name;<\/pre>\n<p>\u56db\u3001\u4f7f\u7528MAX\u548cMIN\u51fd\u6570\u8fdb\u884c\u6700\u5927\u503c\u548c\u6700\u5c0f\u503c\u8ba1\u7b97<\/p>\n<p>MAX\u51fd\u6570\u7528\u4e8e\u8ba1\u7b97\u6307\u5b9a\u5217\u6216\u8868\u4e2d\u6570\u503c\u578b\u5b57\u6bb5\u7684\u6700\u5927\u503c\uff0c\u800cMIN\u51fd\u6570\u7528\u4e8e\u8ba1\u7b97\u6307\u5b9a\u5217\u6216\u8868\u4e2d\u6570\u503c\u578b\u5b57\u6bb5\u7684\u6700\u5c0f\u503c\u3002<\/p>\n<p>\u793a\u4f8b5\uff1a\u8ba1\u7b97\u67d0\u4e2a\u5217\u7684\u6700\u5927\u503c\u548c\u6700\u5c0f\u503c<\/p>\n<pre>SELECT MAX(column_name) AS max_value, MIN(column_name) AS min_value FROM table_name;<\/pre>\n<p>\u4e94\u3001\u4f7f\u7528GROUP BY\u5b50\u53e5\u8fdb\u884c\u5206\u7ec4\u7edf\u8ba1<\/p>\n<p>GROUP BY\u5b50\u53e5\u7528\u4e8e\u5c06\u67e5\u8be2\u7ed3\u679c\u6309\u7167\u6307\u5b9a\u5217\u8fdb\u884c\u5206\u7ec4\uff0c\u7136\u540e\u5bf9\u6bcf\u4e2a\u7ec4\u8fdb\u884c\u7edf\u8ba1\u3002<\/p>\n<p>\u793a\u4f8b6\uff1a\u6309\u7167\u67d0\u4e2a\u5217\u8fdb\u884c\u5206\u7ec4\u7edf\u8ba1<\/p>\n<pre>SELECT column_name, COUNT(*) AS count FROM table_name GROUP BY column_name;<\/pre>\n<p>\u793a\u4f8b7\uff1a\u6309\u7167\u591a\u4e2a\u5217\u8fdb\u884c\u5206\u7ec4\u7edf\u8ba1<\/p>\n<pre>SELECT column_name1, column_name2, COUNT(*) AS count FROM table_name GROUP BY column_name1, column_name2;<\/pre>\n<p>\u516d\u3001\u4f7f\u7528HAVING\u5b50\u53e5\u8fdb\u884c\u6761\u4ef6\u7b5b\u9009<\/p>\n<p>HAVING\u5b50\u53e5\u7528\u4e8e\u5bf9\u5206\u7ec4\u540e\u7684\u7ed3\u679c\u8fdb\u884c\u6761\u4ef6\u7b5b\u9009\u3002<\/p>\n<p>\u793a\u4f8b8\uff1a\u7b5b\u9009\u5206\u7ec4\u540e\u7684\u7ed3\u679c<\/p>\n<pre>SELECT column_name, COUNT(*) AS count FROM table_name GROUP BY column_name HAVING count &gt; 100;<\/pre>\n<p>\u4ee5\u4e0a\u662f\u5728MySQL\u4e2d\u4f7f\u7528SQL\u8bed\u53e5\u8fdb\u884c\u6570\u636e\u805a\u5408\u548c\u7edf\u8ba1\u7684\u5e38\u7528\u65b9\u6cd5\u548c\u4ee3\u7801\u793a\u4f8b\u3002\u6839\u636e\u5b9e\u9645\u9700\u6c42\uff0c\u53ef\u4ee5\u7ed3\u5408\u4e0d\u540c\u7684\u805a\u5408\u51fd\u6570\u3001\u5206\u7ec4\u5217\u548c\u6761\u4ef6\u7b5b\u9009\u6765\u5b8c\u6210\u66f4\u590d\u6742\u7684\u6570\u636e\u5206\u6790\u548c\u7edf\u8ba1\u5de5\u4f5c\u3002<\/p>\n<p>\u7406\u8bba\u8981\u638c\u63e1\uff0c\u5b9e\u64cd\u4e0d\u80fd\u843d\uff01\u4ee5\u4e0a\u5173\u4e8e\u300a\u5982\u4f55\u4f7f\u7528SQL\u8bed\u53e5\u5728MySQL\u4e2d\u8fdb\u884c\u6570\u636e\u805a\u5408\u548c\u7edf\u8ba1\uff1f\u300b\u7684\u8be6\u7ec6\u4ecb\u7ecd\uff0c\u5927\u5bb6\u90fd\u638c\u63e1\u4e86\u5427\uff01\u5982\u679c\u60f3\u8981\u7ee7\u7eed\u63d0\u5347\u81ea\u5df1\u7684\u80fd\u529b\uff0c\u90a3\u4e48\u5c31\u6765\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\u5427\uff01<\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>\u5982\u4f55\u4f7f\u7528SQL\u8bed\u53e5\u5728MySQL\u4e2d&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-199613","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199613","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=199613"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199613\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=199613"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=199613"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=199613"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}