{"id":200479,"date":"2025-05-06T11:21:00","date_gmt":"2025-05-06T03:21:00","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200479\/"},"modified":"2025-05-06T11:21:00","modified_gmt":"2025-05-06T03:21:00","slug":"%e5%a6%82%e4%bd%95%e7%94%a8-sql-%e6%9f%a5%e8%af%a2%e5%9c%a8%e6%8c%87%e5%ae%9a%e6%97%b6%e9%97%b4%e6%ae%b5%e5%86%85%e8%bf%9e%e7%bb%ad%e5%a4%9a%e6%97%a5%e9%83%bd%e6%9c%89%e7%89%b9%e5%ae%9a%e5%95%86","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200479\/","title":{"rendered":"\u5982\u4f55\u7528 SQL \u67e5\u8be2\u5728\u6307\u5b9a\u65f6\u95f4\u6bb5\u5185\u8fde\u7eed\u591a\u65e5\u90fd\u6709\u7279\u5b9a\u5546\u54c1\u5e93\u5b58\u7684\u5546\u5e97\uff1f"},"content":{"rendered":"

<\/b> <\/p>\n

\u5982\u4f55\u7528 SQL \u67e5\u8be2\u5728\u6307\u5b9a\u65f6\u95f4\u6bb5\u5185\u8fde\u7eed\u591a\u65e5\u90fd\u6709\u7279\u5b9a\u5546\u54c1\u5e93\u5b58\u7684\u5546\u5e97\uff1f<\/h1>\n

\u5bf9\u4e8e\u4e00\u4e2a\u6570\u636e\u5e93\u5f00\u53d1\u8005\u6765\u8bf4\uff0c\u7262\u56fa\u624e\u5b9e\u7684\u57fa\u7840\u662f\u5341\u5206\u91cd\u8981\u7684\uff0c\u4e3b\u673a\u5b9d\u8d1d\u5c31\u6765\u5e26\u5927\u5bb6\u4e00\u70b9\u70b9\u7684\u638c\u63e1\u57fa\u7840\u77e5\u8bc6\u70b9\u3002\u4eca\u5929\u672c\u7bc7\u6587\u7ae0\u5e26\u5927\u5bb6\u4e86\u89e3\u300a\u5982\u4f55\u7528 SQL \u67e5\u8be2\u5728\u6307\u5b9a\u65f6\u95f4\u6bb5\u5185\u8fde\u7eed\u591a\u65e5\u90fd\u6709\u7279\u5b9a\u5546\u54c1\u5e93\u5b58\u7684\u5546\u5e97\uff1f\u300b\uff0c\u4e3b\u8981\u4ecb\u7ecd\u4e86\uff0c\u5e0c\u671b\u5bf9\u5927\u5bb6\u7684\u77e5\u8bc6\u79ef\u7d2f\u6709\u6240\u5e2e\u52a9\uff0c\u5feb\u70b9\u6536\u85cf\u8d77\u6765\u5427\uff0c\u5426\u5219\u9700\u8981\u65f6\u5c31\u627e\u4e0d\u5230\u4e86\uff01<\/p>\n

<\/p>\n

sql \u5b9e\u73b0\u601d\u8def<\/strong><\/p>\n

\u5982\u4f55\u67e5\u8be2\u5728\u6307\u5b9a\u65f6\u95f4\u6bb5\u5185\u8fde\u7eed\u591a\u65e5\u90fd\u6709\u7279\u5b9a\u5546\u54c1\u5e93\u5b58\u7684\u5546\u5e97\uff1f\u4ee5\u4e0b\u662f\u4e00\u4e2a sql \u5b9e\u73b0\u601d\u8def\uff1a<\/p>\n

\u901a\u8fc7 union \u64cd\u4f5c\u7b26\uff0c\u628a\u6bcf\u5929\u5e93\u5b58\u4fe1\u606f\u62fc\u63a5\u5230\u4e00\u8d77\uff0c\u5f62\u6210\u4e00\u5f20\u4e34\u65f6\u8868\uff1a<\/p>\n

select \u5546\u5e97 from \u8868 where \u65e5\u671f='2021-09-01'  -- and \u540e\u7eed\u53ef\u4ee5\u6dfb\u52a0\u4e0d\u540c\u7684\u5546\u54c1\u4fe1\u606f\nunion\nselect \u5546\u5e97 from \u8868 where \u65e5\u671f='2021-09-02'\nunion\nselect \u5546\u5e97 from \u8868 where \u65e5\u671f='2021-09-03'<\/pre>\n
\u7136\u540e\u5bf9\u4e34\u65f6\u8868\u8fdb\u884c\u5206\u7ec4\uff0c\u7edf\u8ba1\u6bcf\u5bb6\u5546\u5e97\u51fa\u73b0\u5728\u4e0d\u540c\u65e5\u671f\u7684\u6b21\u6570\uff1a<\/p>\n
select \u5546\u5e97,count(distinct \u65e5\u671f) countdate \nfrom (\n    select \u5546\u5e97 from \u8868 where \u65e5\u671f='2021-09-01'  -- and \u540e\u7eed\u53ef\u4ee5\u6dfb\u52a0\u4e0d\u540c\u7684\u5546\u54c1\u4fe1\u606f\n    union\n    select \u5546\u5e97 from \u8868 where \u65e5\u671f='2021-09-02'\n    union\n    select \u5546\u5e97 from \u8868 where \u65e5\u671f='2021-09-03'\n) as tab \ngroup by \u5546\u5e97<\/pre>\n
\u6700\u540e\uff0c\u7b5b\u9009\u51fa\u8fde\u7eed\u591a\u65e5\u90fd\u6709\u5e93\u5b58\u7684\u5546\u5e97\uff1a<\/p>\n
HAVING countdate=3<\/pre>\n
\u8fd9\u6837\uff0c\u5c31\u53ef\u4ee5\u67e5\u8be2\u5230\u5728 9 \u6708 1 \u65e5\u30012 \u65e5\u30013 \u65e5\u90fd\u6709\u6307\u5b9a\u5546\u54c1\u5e93\u5b58\u7684\u5546\u5e97\u3002<\/p>\n
\u597d\u4e86\uff0c\u672c\u6587\u5230\u6b64\u7ed3\u675f\uff0c\u5e26\u5927\u5bb6\u4e86\u89e3\u4e86\u300a\u5982\u4f55\u7528 SQL \u67e5\u8be2\u5728\u6307\u5b9a\u65f6\u95f4\u6bb5\u5185\u8fde\u7eed\u591a\u65e5\u90fd\u6709\u7279\u5b9a\u5546\u54c1\u5e93\u5b58\u7684\u5546\u5e97\uff1f\u300b\uff0c\u5e0c\u671b\u672c\u6587\u5bf9\u4f60\u6709\u6240\u5e2e\u52a9\uff01\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff0c\u7ed9\u5927\u5bb6\u5206\u4eab\u66f4\u591a\u6570\u636e\u5e93\u77e5\u8bc6\uff01<\/p>\n
\n
\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"
\u5982\u4f55\u7528 SQL \u67e5\u8be2\u5728\u6307\u5b9a\u65f6\u95f4\u6bb5...<\/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-200479","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200479","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=200479"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200479\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200479"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200479"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200479"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}