{"id":145347,"date":"2022-05-14T09:41:56","date_gmt":"2022-05-14T01:41:56","guid":{"rendered":"http:\/\/www.idc.net\/help\/145347\/"},"modified":"2022-05-14T09:41:56","modified_gmt":"2022-05-14T01:41:56","slug":"%e5%a6%82%e4%bd%95%e7%94%a8-sql-%e5%8f%96%e5%87%ba%e6%95%b0%e6%8d%ae%e5%ba%93%e4%b8%ad%e6%9c%80%e6%96%b0%e7%9a%84%e6%97%a5%e6%9c%9f%e6%95%b0%e6%8d%ae%ef%bc%9f-sql-%e5%8f%96%e6%97%a5%e6%9c%9f%e6%9c%80","status":"publish","type":"post","link":"https:\/\/idc.net\/help\/145347\/","title":{"rendered":"\u5982\u4f55\u7528 SQL \u53d6\u51fa\u6570\u636e\u5e93\u4e2d\u6700\u65b0\u7684\u65e5\u671f\u6570\u636e\uff1f (sql \u53d6\u65e5\u671f\u6700\u540e\u4e00\u6761\u6570\u636e\u5e93)"},"content":{"rendered":"<p>\u5728\u65e5\u5e38\u6570\u636e\u5e93\u64cd\u4f5c\u4e2d\uff0c\u6211\u4eec\u7ecf\u5e38\u9700\u8981\u5728\u6570\u636e\u96c6\u4e2d\u83b7\u53d6\u6700\u65b0\u7684\u65e5\u671f\u6570\u636e\uff0c\u4f8b\u5982\u6700\u8fd1\u66f4\u65b0\u7684\u6570\u636e\uff0c\u6700\u65b0\u6ce8\u518c\u7684\u7528\u6237\u7b49\u7b49\u3002\u8fd9\u4e9b\u64cd\u4f5c\u90fd\u9700\u8981\u7528\u5230 SQL \u8bed\u53e5\u6765\u5b9e\u73b0\u3002\u5728\u672c\u6587\u4e2d\uff0c\u6211\u4eec\u5c06\u5206\u4eab\u4e00\u4e9b\u65b9\u6cd5\u6765\u5982\u4f55\u7528 SQL \u53d6\u51fa\u6570\u636e\u5e93\u4e2d\u6700\u65b0\u7684\u65e5\u671f\u6570\u636e\u3002<\/p>\n<p>\u65b9\u6cd5\u4e00\uff1a\u4f7f\u7528 MAX \u51fd\u6570<\/p>\n<p>MAX \u51fd\u6570\u53ef\u7528\u4e8e\u5728\u6570\u636e\u96c6\u4e2d\u67e5\u627e\u66f4\u5927\u503c\u3002\u5bf9\u4e8e\u65e5\u671f\u6570\u636e\u7c7b\u578b\uff0cMAX \u51fd\u6570\u5c06\u8fd4\u56de\u6700\u8fd1\u7684\u65e5\u671f\u3002\u4e0b\u9762\u662f\u4e00\u4e2a\u793a\u4f8b\uff1a<\/p>\n<p>SELECT MAX(create_date) FROM users;<\/p>\n<p>\u4ee5\u4e0a SQL \u67e5\u8be2\u5c06\u8fd4\u56de\u5728 users \u8868\u4e2d\u7684\u6700\u8fd1\u7684 create_date \u503c\u3002\u8bf7\u6ce8\u610f\uff0c\u4e0a\u8ff0\u8bed\u53e5\u5047\u8bbe create_date \u5217\u662f\u4e00\u4e2a\u65e5\u671f\u6570\u636e\u7c7b\u578b\u3002<\/p>\n<p>\u5982\u679c\u60a8\u9700\u8981\u83b7\u53d6\u6700\u65b0\u7684\u8bb0\u5f55\uff0c\u53ef\u4ee5\u5c06 MAX \u51fd\u6570\u4e0e WHERE \u5b50\u53e5\u4e00\u8d77\u4f7f\u7528\uff1a<\/p>\n<p>SELECT * FROM users WHERE create_date = (SELECT MAX(create_date) FROM users);<\/p>\n<p>\u8fd9\u5c06\u8fd4\u56de create_date \u503c\u66f4\u5927\u7684\u8bb0\u5f55\uff0c\u5373\u6700\u65b0\u7684\u8bb0\u5f55\u3002<\/p>\n<p>\u65b9\u6cd5\u4e8c\uff1a\u4f7f\u7528 ORDER BY \u5b50\u53e5<\/p>\n<p>ORDER BY \u5b50\u53e5\u53ef\u7528\u4e8e\u5bf9\u7ed3\u679c\u96c6\u8fdb\u884c\u6392\u5e8f\u3002\u5728\u65e5\u671f\u6570\u636e\u7c7b\u578b\u7684\u60c5\u51b5\u4e0b\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528 ORDER BY \u5b50\u53e5\u6309\u7167\u65e5\u671f\u6392\u5e8f\uff0c\u5e76\u9009\u62e9\u6700\u65b0\u7684\u65e5\u671f\uff1a<\/p>\n<p>SELECT * FROM users ORDER BY create_date DESC LIMIT 1;<\/p>\n<p>\u4ee5\u4e0a SQL \u67e5\u8be2\u5c06\u8fd4\u56de\u6700\u65b0\u7684\u8bb0\u5f55\uff0c\u56e0\u4e3a ORDER BY \u5b50\u53e5\u6309\u7167 create_date \u4ece\u6700\u8fd1\u5230\u6700\u4e45\u8fdc\u7684\u987a\u5e8f\u6392\u5e8f\uff0c\u5e76\u4e14 LIMIT \u5b50\u53e5\u4ec5\u9009\u62e9\u7ed3\u679c\u96c6\u7684\u4e4b\u4e00\u884c\u6570\u636e\u3002<\/p>\n<p>\u65b9\u6cd5\u4e09\uff1a\u4f7f\u7528 TOP \u5b50\u53e5<\/p>\n<p>TOP \u5b50\u53e5\u4ec5\u5728\u4e00\u4e9b\u7279\u5b9a\u7684\u6570\u636e\u5e93\u7cfb\u7edf\u4e2d\u4f7f\u7528\uff0c\u4f8b\u5982 Microsoft SQL Server\u3002\u7c7b\u4f3c LIMIT \u5b50\u53e5\uff0cTOP \u5b50\u53e5\u53ef\u7528\u4e8e\u63a7\u5236\u6570\u636e\u5e93\u67e5\u8be2\u7ed3\u679c\u96c6\u7684\u884c\u6570\u3002\u4ee5\u4e0b\u793a\u4f8b\u5c55\u793a\u4e86\u5982\u4f55\u4f7f\u7528 TOP \u5b50\u53e5\u6765\u68c0\u7d22\u6700\u8fd1\u7684\u8bb0\u5f55\uff1a<\/p>\n<p>SELECT TOP 1 * FROM users ORDER BY create_date DESC;<\/p>\n<p>\u4ee5\u4e0a SQL \u67e5\u8be2\u5c06\u8fd4\u56de\u6700\u65b0\u7684\u8bb0\u5f55\uff0c\u56e0\u4e3a TOP \u5b50\u53e5\u9009\u62e9\u7ed3\u679c\u96c6\u7684\u4e4b\u4e00\u884c\u6570\u636e\uff0c\u5e76\u4f7f\u7528 ORDER BY \u5b50\u53e5\u6309\u7167 create_date \u4ece\u6700\u8fd1\u5230\u6700\u4e45\u8fdc\u7684\u987a\u5e8f\u6392\u5e8f\u3002<\/p>\n<p>\u65b9\u6cd5\u56db\uff1a\u4f7f\u7528\u5b50\u67e5\u8be2<\/p>\n<p>\u5b50\u67e5\u8be2\u662f\u4e00\u4e2a\u5d4c\u5957\u5728\u4e3b\u67e5\u8be2\u4e2d\u7684\u67e5\u8be2\u8bed\u53e5\u3002\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u5b50\u67e5\u8be2\u6765\u67e5\u627e\u6700\u65b0\u7684\u65e5\u671f\u6570\u636e\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u793a\u4f8b\uff1a<\/p>\n<p>SELECT * FROM users WHERE create_date = (SELECT MAX(create_date) FROM users);<\/p>\n<p>\u4ee5\u4e0a SQL \u67e5\u8be2\u4f7f\u7528\u5b50\u67e5\u8be2\u9009\u62e9\u6700\u8fd1\u7684 create_date \u503c\uff0c\u5e76\u5c06\u8be5\u503c\u7528\u4e8e\u4e3b\u67e5\u8be2\u7684 WHERE \u5b50\u53e5\u4e2d\u3002\u8fd9\u5c06\u8fd4\u56de\u6700\u65b0\u7684\u8bb0\u5f55\u3002<\/p>\n<p>\u5728\u672c\u6587\u4e2d\uff0c\u6211\u4eec\u63d0\u4f9b\u4e86\u56db\u79cd\u65b9\u6cd5\u6765\u7528 SQL \u53d6\u51fa\u6570\u636e\u5e93\u4e2d\u6700\u65b0\u7684\u65e5\u671f\u6570\u636e\u3002\u4f7f\u7528\u8fd9\u4e9b\u65b9\u6cd5\u65f6\uff0c\u8bf7\u786e\u4fdd\u60a8\u7684\u65e5\u671f\u6570\u636e\u683c\u5f0f\u6b63\u786e\uff0c\u4ee5\u4fbf\u5728\u6570\u636e\u5e93\u4e2d\u6b63\u786e\u5730\u5b58\u50a8\u548c\u68c0\u7d22\u65e5\u671f\u503c\u3002\u4f7f\u7528\u8fd9\u4e9b\u6280\u5de7\uff0c\u60a8\u53ef\u4ee5\u8f7b\u677e\u68c0\u7d22\u6700\u65b0\u7684\u8bb0\u5f55\uff0c\u5e76\u786e\u4fdd\u60a8\u7684\u6570\u636e\u96c6\u4fdd\u6301\u6700\u65b0\u72b6\u6001\u3002<\/p>\n<p><strong>\u76f8\u5173\u95ee\u9898\u62d3\u5c55\u9605\u8bfb\uff1a<\/strong><\/p>\n<ul>\n<li>MySql\u4e2d\u5982\u4f55\u7528sql\u8bed\u53e5\u67e5\u8be2\u6570\u636e\u5e93\u4e2d\u6700\u540e\u4e00\u6761\u6570\u636e\u3002<\/li>\n<li>sql\u600e\u4e48\u53d6\u6bcf\u4e2a\u7528\u6237\u6700\u540e\u4e00\u6761\u8bb0\u5f55\uff1f<\/li>\n<\/ul>\n<h3>MySql\u4e2d\u5982\u4f55\u7528sql\u8bed\u53e5\u67e5\u8be2\u6570\u636e\u5e93\u4e2d\u6700\u540e\u4e00\u6761\u6570\u636e\u3002<\/h3>\n<p>\u5982\u679c\u662f\u6ca1\u6709\u89c4\u5f8b\u7684\u53d6\u503c\uff0c\u90a3\u4e48\u662f\u6ca1\u6709\u5b9e\u9645\u610f\u4e49\u7684\uff0c\u5982\u679c\u662f\u4e3a\u4e86\u627e\u5b57\u6bb5\u7684\u53d6\u503c\u8303\u56f4\uff0c\u90a3\u4e48\u53ef\u4ee5\u901a\u8fc7\u5347\u5e8f\u548c\u964d\u5e8f\u67e5\u8be2\u4e24\u6b21\uff0c\u5728\u4f5c\u4e3a\u4e00\u4e2a\u7ed3\u679c\u8f93\u51fa\u5b9e\u73b0\u3002<\/p>\n<p>sql\uff1aselect * from(select top 1 * from tblname order by id desc)<\/p>\n<p>union (select top 1 * from tblname order by id asc);<\/p>\n<p>\u89e3\u91ca\uff1a\u5148\u964d\u5e8f\u67e5\u8be2\u51fa\u4e4b\u4e00\u6761\u8bb0\u5f55\uff0c\u7136\u540e\u5728\u5347\u5e8f\u67e5\u8be2\u51fa\u4e4b\u4e00\u6761\u8bb0\u5f55\uff0c\u4e4b\u540e\u5c06\u7ed3\u679c\u4f5c\u4e3a\u4e24\u6761\u6570\u636e\u8f93\u51fa\u3002<\/p>\n<h3>sql\u600e\u4e48\u53d6\u6bcf\u4e2a\u7528\u6237\u6700\u540e\u4e00\u6761\u8bb0\u5f55\uff1f<\/h3>\n<p>\u4f60\u8fd9\u6570\u636e\u5e93\u6ca1\u8bbe\u8ba1\u552f\u4e00\u7684\u5b57\u6bb5\u5417\uff1f<\/p>\n<p>\u6bd4\u5982\u4f60\u52a0\u4e00\u4e2a\u81ea\u589e\u578b\u7684\u5b57\u6bb5\u3002<\/p>\n<p>\u7136\u540e\u4f60select top 1 * from table order by \u81ea\u589e\u5b57\u6bb5 DESC<\/p>\n<p>\u5c31\u53d6\u5f97\u6700\u540e\u4e00\u6761\u8bb0\u5f55\u4e86\u3002<\/p>\n<p>???<\/p>\n<p>\u4ec0\u4e48\u610f\u601d\u989d<\/p>\n<p>\u5c31\u662f\u5355\u7eaf\u7684\u53d6\u6700\u540e\u4e00\u6761\u8bb0\u5f55\u4e48<\/p>\n<p>\u8fd8\u662f\u8bf4\u201d\u4e4b\u4e00\u540d\u201d \u201c\u6700\u540e\u4e00\u540d\u201d \u8fd9\u6837\u7684\u6761\u4ef6\u5462<\/p>\n<p>select top 1 * from table order by Rq DESC<\/p>\n<p>select Gh,max(Rq) from tableName group by Gh<\/p>\n<p>\u65e5\u671f\u548c\u65f6\u95f4\u5206\u5f00\u5e72\u561b\uff01\u81ea\u627e\u9ebb\u70e6\u5440\uff01<\/p>\n<p>sql \u53d6\u65e5\u671f\u6700\u540e\u4e00\u6761\u6570\u636e\u5e93\u7684\u4ecb\u7ecd\u5c31\u804a\u5230\u8fd9\u91cc\u5427\uff0c\u611f\u8c22\u4f60\u82b1\u65f6\u95f4\u9605\u8bfb\u672c\u7ad9\u5185\u5bb9\uff0c\u66f4\u591a\u5173\u4e8esql \u53d6\u65e5\u671f\u6700\u540e\u4e00\u6761\u6570\u636e\u5e93,\u5982\u4f55\u7528 SQL \u53d6\u51fa\u6570\u636e\u5e93\u4e2d\u6700\u65b0\u7684\u65e5\u671f\u6570\u636e\uff1f,MySql\u4e2d\u5982\u4f55\u7528sql\u8bed\u53e5\u67e5\u8be2\u6570\u636e\u5e93\u4e2d\u6700\u540e\u4e00\u6761\u6570\u636e\u3002,sql\u600e\u4e48\u53d6\u6bcf\u4e2a\u7528\u6237\u6700\u540e\u4e00\u6761\u8bb0\u5f55\uff1f\u7684\u4fe1\u606f\u522b\u5fd8\u4e86\u5728\u672c\u7ad9\u8fdb\u884c\u67e5\u627e\u5594\u3002<\/p>\n<p><a href=\"http:https:\/\/idc.net\/\">\u9999\u6e2f\u670d\u52a1\u5668<\/a>\u9996\u9009\u540e\u6d6a\u4e91\uff0c2H2G\u9996\u670810\u5143\u5f00\u901a\u3002<br \/>\u540e\u6d6a\u4e91\uff08www.IDC.Net\uff09\u63d0\u4f9b\u7b80\u5355\u597d\u7528\uff0c\u4ef7\u683c\u539a\u9053\u7684\u9999\u6e2f\/\u7f8e\u56fd\u4e91\u670d\u52a1\u5668\u548c\u72ec\u7acb\u670d\u52a1\u5668\u3002IDC+ISP+ICP\u8d44\u8d28\u3002ARIN\u548cAPNIC\u4f1a\u5458\u3002\u6210\u719f\u6280\u672f\u56e2\u961f15\u5e74\u884c\u4e1a\u7ecf\u9a8c\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728\u65e5\u5e38\u6570\u636e\u5e93\u64cd\u4f5c\u4e2d\uff0c\u6211\u4eec\u7ecf\u5e38\u9700\u8981\u5728\u6570\u636e\u96c6\u4e2d\u83b7\u53d6\u6700\u65b0\u7684\u65e5\u671f\u6570\u636e\uff0c\u4f8b\u5982\u6700\u8fd1\u66f4\u65b0\u7684\u6570\u636e\uff0c\u6700\u65b0\u6ce8\u518c\u7684\u7528\u6237\u7b49\u7b49\u3002\u8fd9\u4e9b\u64cd\u4f5c [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7038],"tags":[],"class_list":["post-145347","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts\/145347","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/comments?post=145347"}],"version-history":[{"count":0,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts\/145347\/revisions"}],"wp:attachment":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/media?parent=145347"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/categories?post=145347"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/tags?post=145347"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}