{"id":6847,"date":"2024-11-14T10:58:22","date_gmt":"2024-11-14T02:58:22","guid":{"rendered":"https:\/\/fwq.ai\/blog\/6847\/"},"modified":"2024-11-14T10:58:22","modified_gmt":"2024-11-14T02:58:22","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:\/\/fwq.ai\/blog\/6847\/","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":"<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/001\/246\/273\/172999423245082.jpg\" class=\"aligncenter\" title=\"\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\u63d2\u56fe\" alt=\"\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\u63d2\u56fe\" \/><\/p>\n<p><strong>sql \u5b9e\u73b0\u601d\u8def<\/strong><\/p>\n<p>\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<p>\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<pre>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<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p>\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<pre>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<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p>\u6700\u540e\uff0c\u7b5b\u9009\u51fa\u8fde\u7eed\u591a\u65e5\u90fd\u6709\u5e93\u5b58\u7684\u5546\u5e97\uff1a<\/p>\n<pre>HAVING countdate=3<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p>\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<p>\u4ee5\u4e0a\u5c31\u662f\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\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u7f51\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>sql \u5b9e\u73b0\u601d\u8def \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 \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 select \u5546\u5e97 from \u8868 where \u65e5\u671f=&#8217;2021-09-01&#8242; &#8212; and \u540e\u7eed\u53ef\u4ee5\u6dfb\u52a0\u4e0d\u540c\u7684\u5546\u54c1\u4fe1\u606f union select \u5546\u5e97 from \u8868 where \u65e5\u671f=&#8217;2021-09-02&#8242; union select \u5546\u5e97 from \u8868 where \u65e5\u671f=&#8217;2021-09-03&#8242; \u767b\u5f55\u540e\u590d\u5236 \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 select \u5546\u5e97,count(distinct \u65e5\u671f) countdate from ( select \u5546\u5e97 from \u8868 where \u65e5\u671f=&#8217;2021-09-01&#8242; &#8212; and \u540e\u7eed\u53ef\u4ee5\u6dfb\u52a0\u4e0d\u540c\u7684\u5546\u54c1\u4fe1\u606f union select \u5546\u5e97 from \u8868 where \u65e5\u671f=&#8217;2021-09-02&#8242; [&hellip;]<\/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-6847","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/6847","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=6847"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/6847\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=6847"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=6847"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=6847"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}