{"id":27297,"date":"2024-11-24T09:30:25","date_gmt":"2024-11-24T01:30:25","guid":{"rendered":"https:\/\/fwq.ai\/blog\/27297\/"},"modified":"2024-11-24T09:30:25","modified_gmt":"2024-11-24T01:30:25","slug":"sql-%e6%9f%a5%e8%af%a2%e4%b8%ad%ef%bc%8c%e8%81%9a%e5%90%88%e5%87%bd%e6%95%b0%e5%92%8c%e6%8e%92%e5%ba%8f%e7%9a%84%e6%89%a7%e8%a1%8c%e9%a1%ba%e5%ba%8f%e6%98%af%e6%80%8e%e6%a0%b7%e7%9a%84%ef%bc%9f-2","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/27297\/","title":{"rendered":"SQL \u67e5\u8be2\u4e2d\uff0c\u805a\u5408\u51fd\u6570\u548c\u6392\u5e8f\u7684\u6267\u884c\u987a\u5e8f\u662f\u600e\u6837\u7684\uff1f"},"content":{"rendered":"<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/001\/246\/273\/173122597314145.jpg\" class=\"aligncenter\" title=\"SQL \u67e5\u8be2\u4e2d\uff0c\u805a\u5408\u51fd\u6570\u548c\u6392\u5e8f\u7684\u6267\u884c\u987a\u5e8f\u662f\u600e\u6837\u7684\uff1f\u63d2\u56fe\" alt=\"SQL \u67e5\u8be2\u4e2d\uff0c\u805a\u5408\u51fd\u6570\u548c\u6392\u5e8f\u7684\u6267\u884c\u987a\u5e8f\u662f\u600e\u6837\u7684\uff1f\u63d2\u56fe\" \/><\/p>\n<p><strong>\u6570\u636e\u5e93\u8bed\u6cd5\u96be\u9898\uff1a\u4e0e\u6392\u5e8f\u6267\u884c\u987a\u5e8f<\/strong><\/p>\n<p>\u5728 sql \u67e5\u8be2\u4e2d\uff0c\u5f53\u6d89\u53ca\u5230\u805a\u5408\u51fd\u6570\u548c\u6392\u5e8f\u65f6\uff0c\u4e86\u89e3\u5b83\u4eec\u7684\u6267\u884c\u987a\u5e8f\u81f3\u5173\u91cd\u8981\u3002\u672c\u6587\u5c06\u63a2\u8ba8\u4e0b\u8ff0\u67e5\u8be2\u7684\u6267\u884c\u987a\u5e8f\uff1a<\/p>\n<pre>SELECT COUNT(*) AS count FROM table_name ORDER BY column_name;<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p><strong>\u805a\u5408\u51fd\u6570 vs. \u6392\u5e8f<\/strong><\/p>\n<p>\u805a\u5408\u51fd\u6570\uff0c\u5982 count()\uff0c\u7528\u4e8e\u5728\u6570\u636e\u96c6\u4e2d\u805a\u5408\u503c\uff0c\u800c\u6392\u5e8f\u7528\u4e8e\u5bf9\u7ed3\u679c\u96c6\u8fdb\u884c\u6392\u5e8f\u3002\u5728\u6267\u884c\u67e5\u8be2\u65f6\uff0c\u8fd9\u4e24\u4e2a\u64cd\u4f5c\u7684\u5904\u7406\u987a\u5e8f\u4f1a\u5f71\u54cd\u7ed3\u679c\u3002<\/p>\n<p>\u901a\u5e38\uff0c\u6392\u5e8f\u64cd\u4f5c\u662f\u6700\u540e\u6267\u884c\u7684\u3002\u8fd9\u662f\u56e0\u4e3a\uff0c\u5728\u805a\u5408\u64cd\u4f5c\u5b8c\u6210\u4e4b\u524d\uff0c\u7ed3\u679c\u96c6\u4e2d\u7684\u6570\u636e\u5c1a\u672a\u805a\u5408\u3002\u5982\u679c\u6392\u5e8f\u5728\u805a\u5408\u4e4b\u524d\u6267\u884c\uff0c\u90a3\u4e48\u6392\u5e8f\u4f9d\u636e\u7684\u6570\u636e\u5c31\u4f1a\u4e0d\u51c6\u786e\uff0c\u5bfc\u81f4\u9519\u8bef\u7684\u7ed3\u679c\u3002<\/p>\n<p><strong>\u8be5\u67e5\u8be2\u7684\u6267\u884c\u987a\u5e8f<\/strong><\/p>\n<p>\u9488\u5bf9\u4e0a\u8ff0\u67e5\u8be2\uff0c\u6267\u884c\u987a\u5e8f\u5982\u4e0b\uff1a<\/p>\n<ol>\n<li> <strong>\u805a\u5408\uff1a<\/strong>\u8ba1\u7b97 count() \u805a\u5408\u51fd\u6570\uff0c\u6309\u6bcf\u7ec4 column_name \u805a\u5408\u884c\u5e76\u8fd4\u56de\u8ba1\u6570\u3002<\/li>\n<li> <strong>\u6392\u5e8f\uff1a<\/strong>\u5bf9\u805a\u5408\u540e\u7684\u7ed3\u679c\u96c6\u6309 column_name \u5217\u8fdb\u884c\u6392\u5e8f\u3002<\/li>\n<\/ol>\n<p>\u8fd9\u79cd\u6267\u884c\u987a\u5e8f\u786e\u4fdd\u4e86\u6392\u5e8f\u4f9d\u636e\u7684\u6570\u636e\u662f\u51c6\u786e\u7684\uff0c\u4ece\u800c\u4ea7\u751f\u6b63\u786e\u7684\u6392\u5e8f\u7ed3\u679c\u3002<\/p>\n<p>\u4ee5\u4e0a\u5c31\u662fSQL \u67e5\u8be2\u4e2d\uff0c\u548c\u6392\u5e8f\u7684\u6267\u884c\u987a\u5e8f\u662f\u600e\u6837\u7684\uff1f\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6570\u636e\u5e93\u8bed\u6cd5\u96be\u9898\uff1a\u4e0e\u6392\u5e8f\u6267\u884c\u987a\u5e8f \u5728 sql \u67e5\u8be2\u4e2d\uff0c\u5f53\u6d89\u53ca\u5230\u805a\u5408\u51fd\u6570\u548c\u6392\u5e8f\u65f6\uff0c\u4e86\u89e3\u5b83\u4eec\u7684\u6267\u884c\u987a\u5e8f\u81f3\u5173\u91cd\u8981\u3002\u672c\u6587\u5c06\u63a2\u8ba8\u4e0b\u8ff0\u67e5\u8be2\u7684\u6267\u884c\u987a\u5e8f\uff1a SELECT COUNT(*) AS count FROM table_name ORDER BY column_name; \u767b\u5f55\u540e\u590d\u5236 \u805a\u5408\u51fd\u6570 vs. \u6392\u5e8f \u805a\u5408\u51fd\u6570\uff0c\u5982 count()\uff0c\u7528\u4e8e\u5728\u6570\u636e\u96c6\u4e2d\u805a\u5408\u503c\uff0c\u800c\u6392\u5e8f\u7528\u4e8e\u5bf9\u7ed3\u679c\u96c6\u8fdb\u884c\u6392\u5e8f\u3002\u5728\u6267\u884c\u67e5\u8be2\u65f6\uff0c\u8fd9\u4e24\u4e2a\u64cd\u4f5c\u7684\u5904\u7406\u987a\u5e8f\u4f1a\u5f71\u54cd\u7ed3\u679c\u3002 \u901a\u5e38\uff0c\u6392\u5e8f\u64cd\u4f5c\u662f\u6700\u540e\u6267\u884c\u7684\u3002\u8fd9\u662f\u56e0\u4e3a\uff0c\u5728\u805a\u5408\u64cd\u4f5c\u5b8c\u6210\u4e4b\u524d\uff0c\u7ed3\u679c\u96c6\u4e2d\u7684\u6570\u636e\u5c1a\u672a\u805a\u5408\u3002\u5982\u679c\u6392\u5e8f\u5728\u805a\u5408\u4e4b\u524d\u6267\u884c\uff0c\u90a3\u4e48\u6392\u5e8f\u4f9d\u636e\u7684\u6570\u636e\u5c31\u4f1a\u4e0d\u51c6\u786e\uff0c\u5bfc\u81f4\u9519\u8bef\u7684\u7ed3\u679c\u3002 \u8be5\u67e5\u8be2\u7684\u6267\u884c\u987a\u5e8f \u9488\u5bf9\u4e0a\u8ff0\u67e5\u8be2\uff0c\u6267\u884c\u987a\u5e8f\u5982\u4e0b\uff1a \u805a\u5408\uff1a\u8ba1\u7b97 count() \u805a\u5408\u51fd\u6570\uff0c\u6309\u6bcf\u7ec4 column_name \u805a\u5408\u884c\u5e76\u8fd4\u56de\u8ba1\u6570\u3002 \u6392\u5e8f\uff1a\u5bf9\u805a\u5408\u540e\u7684\u7ed3\u679c\u96c6\u6309 column_name \u5217\u8fdb\u884c\u6392\u5e8f\u3002 \u8fd9\u79cd\u6267\u884c\u987a\u5e8f\u786e\u4fdd\u4e86\u6392\u5e8f\u4f9d\u636e\u7684\u6570\u636e\u662f\u51c6\u786e\u7684\uff0c\u4ece\u800c\u4ea7\u751f\u6b63\u786e\u7684\u6392\u5e8f\u7ed3\u679c\u3002 \u4ee5\u4e0a\u5c31\u662fSQL \u67e5\u8be2\u4e2d\uff0c\u548c\u6392\u5e8f\u7684\u6267\u884c\u987a\u5e8f\u662f\u600e\u6837\u7684\uff1f\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-27297","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/27297","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=27297"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/27297\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=27297"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=27297"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=27297"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}