{"id":3589,"date":"2016-06-22T17:37:57","date_gmt":"2016-06-22T09:37:57","guid":{"rendered":"http:\/\/www.wpadmin.cn\/blog\/?p=3589"},"modified":"2016-06-22T17:37:57","modified_gmt":"2016-06-22T09:37:57","slug":"%e5%8f%af%e4%bb%a5%e8%bf%99%e6%a0%b7%e5%8e%bb%e7%90%86%e8%a7%a3group-by%e5%92%8c%e8%81%9a%e5%90%88%e5%87%bd%e6%95%b0","status":"publish","type":"post","link":"https:\/\/www.wpadmin.cn\/blog\/3589.html","title":{"rendered":"\u53ef\u4ee5\u8fd9\u6837\u53bb\u7406\u89e3group by\u548c\u805a\u5408\u51fd\u6570"},"content":{"rendered":"<p>\u5199\u5728\u524d\u9762\u7684\u8bdd\uff1a\u7528\u4e86\u597d\u4e45group by\uff0c\u4eca\u5929\u65e9\u4e0a\u4e00\u89c9\u9192\u6765\uff0c\u7a81\u7136\u611f\u89c9group by\u597d\u964c\u751f\uff0c\u603b\u6709\u4e2a\u7b4b\u522b\u4e0d\u8fc7\u6765\uff0c\u4e3a\u4ec0\u4e48\u4e0d\u80fd\u591fselect * from Table group by id\uff0c\u4e3a\u4ec0\u4e48\u4e00\u5b9a\u4e0d\u80fd\u662f*\uff0c\u800c\u662f\u67d0\u4e00\u4e2a\u5217\u6216\u8005\u67d0\u4e2a\u5217\u7684\u805a\u5408\u51fd\u6570\uff0cgroup by \u591a\u4e2a\u5b57\u6bb5\u53ef\u4ee5\u600e\u4e48\u53bb\u5f88\u597d\u7684\u7406\u89e3\u5462\uff1f\u4e0d\u8fc7\u6700\u540e\u8fd8\u662f\u8f6c\u8fc7\u6765\u4e86\uff0c\u7b80\u5355\u5199\u5199\u5427\uff0c\u5927\u725b\u4eec\u76f4\u63a5\u7565\u8fc7\u5427\u3002<\/p>\n<p>=========\u6b63\u6587\u5f00\u59cb===========<\/p>\n<p>\u5148\u6765\u770b\u4e0b\u88681\uff0c\u8868\u540d\u4e3atest\uff1a<\/p>\n<p><img decoding=\"async\" class=\"alignCenter\" src=\"http:\/\/img0.tuicool.com\/fiMNfm3.jpg!web\" alt=\"\" \/><\/p>\n<h4>\u88681<\/h4>\n<p>\u6267\u884c\u5982\u4e0bSQL\u8bed\u53e5\uff1a<\/p>\n<pre class=\"sql\"><span class=\"operator\"><span class=\"keyword\">SELECT<\/span> name <span class=\"keyword\">FROM<\/span> test\r\n<span class=\"keyword\">GROUP<\/span> <span class=\"keyword\">BY<\/span> name<\/span><\/pre>\n<p>\u4f60\u5e94\u8be5\u5f88\u5bb9\u6613\u77e5\u9053\u8fd0\u884c\u7684\u7ed3\u679c\uff0c\u6ca1\u9519\uff0c\u5c31\u662f\u4e0b\u88682\uff1a<\/p>\n<p><img decoding=\"async\" class=\"breakLine\" src=\"http:\/\/img0.tuicool.com\/uE3UZb.jpg!web\" alt=\"\" \/><\/p>\n<h4>\u88682<\/h4>\n<p>\u53ef\u662f\u4e3a\u4e86\u80fd\u591f\u66f4\u597d\u7684\u7406\u89e3 <strong>\u201cgroup by\u201d\u591a\u4e2a\u5217\u201c<\/strong> \u548c <strong>\u201d\u805a\u5408\u51fd\u6570\u201c<\/strong> \u7684\u5e94\u7528\uff0c\u6211\u5efa\u8bae\u5728\u601d\u8003\u7684\u8fc7\u7a0b\u4e2d\uff0c\u7531\u88681\u5230\u88682\u7684\u8fc7\u7a0b\u4e2d\uff0c\u589e\u52a0\u4e00\u4e2a\u865a\u6784\u7684\u4e2d\u95f4\u8868\uff1a <strong>\u865a\u62df\u88683<\/strong> \u3002\u4e0b\u9762\u8bf4\u8bf4\u5982\u4f55\u6765\u601d\u8003\u4e0a\u9762SQL\u8bed\u53e5\u6267\u884c\u60c5\u51b5\uff1a<\/p>\n<p>1.FROM test\uff1a\u8be5\u53e5\u6267\u884c\u540e\uff0c\u5e94\u8be5\u7ed3\u679c\u548c\u88681\u4e00\u6837\uff0c\u5c31\u662f\u539f\u6765\u7684\u8868\u3002<\/p>\n<p>2.FROM test Group BY name\uff1a\u8be5\u53e5\u6267\u884c\u540e\uff0c\u6211\u4eec\u60f3\u8c61\u751f\u6210\u4e86 <strong>\u865a\u62df\u88683\uff0c<\/strong> \u5982\u4e0b\u6240\u56fe\u6240\u793a\uff0c\u751f\u6210\u8fc7\u7a0b\u662f\u8fd9\u6837\u7684\uff1agroup by name\uff0c\u90a3\u4e48\u627ename\u90a3\u4e00\u5217\uff0c\u5177\u6709\u76f8\u540cname\u503c\u7684\u884c\uff0c\u5408\u5e76\u6210\u4e00\u884c\uff0c\u5982\u5bf9\u4e8ename\u503c\u4e3aaa\u7684\uff0c\u90a3\u4e48&lt;1 aa 2&gt;\u4e0e&lt;2 aa 3&gt;\u4e24\u884c\u5408\u5e76\u62101\u884c\uff0c\u6240\u6709\u7684id\u503c\u548cnumber\u503c\u5199\u5230\u4e00\u4e2a\u5355\u5143\u683c\u91cc\u9762\u3002<\/p>\n<p><img decoding=\"async\" class=\"alignCenter\" src=\"http:\/\/img0.tuicool.com\/iuayMj2.jpg!web\" alt=\"\" \/><\/p>\n<p>3.\u63a5\u4e0b\u6765\u5c31\u8981\u9488\u5bf9 <strong>\u865a\u62df\u88683<\/strong> \u6267\u884cSelect\u8bed\u53e5\u4e86\uff1a<\/p>\n<p>\uff081\uff09\u5982\u679c\u6267\u884cselect *\u7684\u8bdd\uff0c\u90a3\u4e48\u8fd4\u56de\u7684\u7ed3\u679c\u5e94\u8be5\u662f\u865a\u62df\u88683\uff0c\u53ef\u662fid\u548cnumber\u4e2d\u6709\u7684\u5355\u5143\u683c\u91cc\u9762\u7684\u5185\u5bb9\u662f\u591a\u4e2a\u503c\u7684\uff0c\u800c\u5173\u7cfb\u6570\u636e\u5e93\u5c31\u662f\u57fa\u4e8e\u5173\u7cfb\u7684\uff0c\u5355\u5143\u683c\u4e2d\u662f\u4e0d\u5141\u8bb8\u6709\u591a\u4e2a\u503c\u7684\uff0c\u6240\u4ee5\u4f60\u770b\uff0c\u6267\u884cselect * \u8bed\u53e5\u5c31\u62a5\u9519\u4e86\u3002<\/p>\n<p>\uff082\uff09\u6211\u4eec\u518d\u770bname\u5217\uff0c\u6bcf\u4e2a\u5355\u5143\u683c\u53ea\u6709\u4e00\u4e2a\u6570\u636e\uff0c\u6240\u4ee5\u6211\u4eecselect name\u7684\u8bdd\uff0c\u5c31\u6ca1\u6709\u95ee\u9898\u4e86\u3002\u4e3a\u4ec0\u4e48name\u5217\u6bcf\u4e2a\u5355\u5143\u683c\u53ea\u6709\u4e00\u4e2a\u503c\u5462\uff0c\u56e0\u4e3a\u6211\u4eec\u5c31\u662f\u7528name\u5217\u6765group by\u7684\u3002<\/p>\n<p>\uff083\uff09\u90a3\u4e48\u5bf9\u4e8eid\u548cnumber\u91cc\u9762\u7684\u5355\u5143\u683c\u6709\u591a\u4e2a\u6570\u636e\u7684\u60c5\u51b5\u600e\u4e48\u529e\u5462\uff1f\u7b54\u6848\u5c31\u662f\u7528\u805a\u5408\u51fd\u6570\uff0c\u805a\u5408\u51fd\u6570\u5c31\u7528\u6765\u8f93\u5165\u591a\u4e2a\u6570\u636e\uff0c\u8f93\u51fa\u4e00\u4e2a\u6570\u636e\u7684\u3002 \u5982cout(id)\uff0csum(number)\uff0c\u800c\u6bcf\u4e2a\u805a\u5408\u51fd\u6570\u7684\u8f93\u5165\u5c31\u662f\u6bcf\u4e00\u4e2a\u591a\u6570\u636e\u7684\u5355\u5143\u683c\u3002<\/p>\n<p>\uff084\uff09\u4f8b\u5982\u6211\u4eec\u6267\u884cselect name,sum(number) from test group by name\uff0c\u90a3\u4e48sum\u5c31\u5bf9\u865a\u62df\u88683\u7684number\u5217\u7684\u6bcf\u4e2a\u5355\u5143\u683c\u8fdb\u884csum\u64cd\u4f5c\uff0c\u4f8b\u5982\u5bf9name\u4e3aaa\u7684\u90a3\u4e00\u884c\u7684number\u5217\u6267\u884csum\u64cd\u4f5c\uff0c\u53732+3\uff0c\u8fd4\u56de5\uff0c\u6700\u540e\u6267\u884c\u7ed3\u679c\u5982\u4e0b\uff1a<\/p>\n<p><img decoding=\"async\" class=\"breakLine\" src=\"http:\/\/img2.tuicool.com\/ZzMBJ3.jpg!web\" alt=\"\" \/><\/p>\n<p>\uff085\uff09group by \u591a\u4e2a\u5b57\u6bb5\u8be5\u600e\u4e48\u7406\u89e3\u5462\uff1a\u5982group by name,number\uff0c\u6211\u4eec\u53ef\u4ee5\u628aname\u548cnumber \u770b\u6210\u4e00\u4e2a <strong>\u6574\u4f53\u5b57\u6bb5<\/strong> \uff0c\u4ee5\u4ed6\u4eec\u6574\u4f53\u6765\u8fdb\u884c\u5206\u7ec4\u7684\u3002\u5982\u4e0b\u56fe<img decoding=\"async\" class=\"alignCenter\" src=\"http:\/\/img1.tuicool.com\/vYvMvqb.jpg!web\" alt=\"\" \/><\/p>\n<p>\uff086\uff09\u63a5\u4e0b\u6765\u5c31\u53ef\u4ee5\u914d\u5408select\u548c\u805a\u5408\u51fd\u6570\u8fdb\u884c\u64cd\u4f5c\u4e86\u3002\u5982\u6267\u884cselect name,sum(id) from test group by name,number\uff0c\u7ed3\u679c\u5982\u4e0b\u56fe\uff1a<\/p>\n<p><img decoding=\"async\" class=\"breakLine\" src=\"http:\/\/img2.tuicool.com\/2yMFvu.jpg!web\" alt=\"\" \/><\/p>\n<p>\u81f3\u6b64\uff0c\u6211\u5df2\u7ecf\u5bf9\u6211\u81ea\u5df1\u5bf9\u5982\u6b64\u7b80\u5355\u7684\u95ee\u9898\u6709\u5982\u6b64\u5929\u9a6c\u884c\u7a7a\u7684\u60f3\u6cd5\u6240\u6298\u670d\uff0c\u6d17\u6d17\u7761\u89c9<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5199\u5728\u524d\u9762\u7684\u8bdd\uff1a\u7528\u4e86\u597d\u4e45group by\uff0c\u4eca\u5929\u65e9\u4e0a\u4e00\u89c9\u9192\u6765\uff0c\u7a81\u7136\u611f\u89c9group by\u597d\u964c\u751f\uff0c\u603b\u6709\u4e2a\u7b4b\u522b\u4e0d\u8fc7\u6765\uff0c\u4e3a\u4ec0\u4e48\u4e0d\u80fd\u591fselect * from Table &#8230; <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[155],"tags":[156,210],"_links":{"self":[{"href":"https:\/\/www.wpadmin.cn\/blog\/wp-json\/wp\/v2\/posts\/3589"}],"collection":[{"href":"https:\/\/www.wpadmin.cn\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wpadmin.cn\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wpadmin.cn\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wpadmin.cn\/blog\/wp-json\/wp\/v2\/comments?post=3589"}],"version-history":[{"count":0,"href":"https:\/\/www.wpadmin.cn\/blog\/wp-json\/wp\/v2\/posts\/3589\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.wpadmin.cn\/blog\/wp-json\/wp\/v2\/media?parent=3589"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wpadmin.cn\/blog\/wp-json\/wp\/v2\/categories?post=3589"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wpadmin.cn\/blog\/wp-json\/wp\/v2\/tags?post=3589"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}