{"id":201053,"date":"2025-05-06T13:55:12","date_gmt":"2025-05-06T05:55:12","guid":{"rendered":"https:\/\/server.hk\/cnblog\/201053\/"},"modified":"2025-05-06T13:55:12","modified_gmt":"2025-05-06T05:55:12","slug":"%e5%a6%82%e4%bd%95%e5%9c%a8-mysql-%e6%9f%a5%e8%af%a2%e4%b8%ad%e5%88%a9%e7%94%a8-exists-%e5%85%b3%e9%94%ae%e8%af%8d%e6%a3%80%e6%9f%a5%e4%b8%a4%e4%b8%aa%e8%a1%a8%e4%b8%ad%e6%98%af%e5%90%a6%e5%ad%98","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/201053\/","title":{"rendered":"\u5982\u4f55\u5728 MySQL \u67e5\u8be2\u4e2d\u5229\u7528 EXISTS \u5173\u952e\u8bcd\u68c0\u67e5\u4e24\u4e2a\u8868\u4e2d\u662f\u5426\u5b58\u5728\u5bf9\u5e94\u503c\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u5982\u4f55\u5728 MySQL \u67e5\u8be2\u4e2d\u5229\u7528 EXISTS \u5173\u952e\u8bcd\u68c0\u67e5\u4e24\u4e2a\u8868\u4e2d\u662f\u5426\u5b58\u5728\u5bf9\u5e94\u503c\uff1f<\/h1>\n<p>\u4eb2\u7231\u7684\u7f16\u7a0b\u5b66\u4e60\u7231\u597d\u8005\uff0c\u5982\u679c\u4f60\u70b9\u5f00\u4e86\u8fd9\u7bc7\u6587\u7ae0\uff0c\u8bf4\u660e\u4f60\u5bf9\u300a\u5982\u4f55\u5728 MySQL \u67e5\u8be2\u4e2d\u5229\u7528 EXISTS \u5173\u952e\u8bcd\u68c0\u67e5\u4e24\u4e2a\u8868\u4e2d\u662f\u5426\u5b58\u5728\u5bf9\u5e94\u503c\uff1f\u300b\u5f88\u611f\u5174\u8da3\u3002\u672c\u7bc7\u6587\u7ae0\u5c31\u6765\u7ed9\u5927\u5bb6\u8be6\u7ec6\u89e3\u6790\u4e00\u4e0b\uff0c\u4e3b\u8981\u4ecb\u7ecd\u4e00\u4e0b\uff0c\u5e0c\u671b\u6240\u6709\u8ba4\u771f\u8bfb\u5b8c\u7684\u7ae5\u978b\u4eec\uff0c\u90fd\u6709\u5b9e\u8d28\u6027\u7684\u63d0\u9ad8\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241128\/17327625026747db8610518.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>\u4f7f\u7528 exists \u5173\u952e\u8bcd\u68c0\u67e5\u4e24\u4e2a\u8868\u4e2d\u662f\u5426\u5b58\u5728\u5bf9\u5e94\u7684\u503c<\/strong><\/p>\n<p>\u5728 mysql \u67e5\u8be2\u4e2d\uff0cexists \u5173\u952e\u8bcd\u7528\u4e8e\u68c0\u67e5\u5b50\u67e5\u8be2\u4e2d\u662f\u5426\u6709\u7ed3\u679c\uff0c\u5982\u679c\u6709\u5219\u8fd4\u56de true\uff0c\u6ca1\u6709\u5219\u8fd4\u56de false\u3002\u8fd9\u4f7f\u5f97\u5b83\u975e\u5e38\u9002\u5408\u68c0\u67e5\u4e24\u4e2a\u8868\u4e2d\u662f\u5426\u5b58\u5728\u5bf9\u5e94\u7684\u503c\u3002<\/p>\n<p>\u4f60\u7684\u76ee\u6807\u662f\u786e\u5b9a\u5b50\u8868\u4e2d\u7684\u6570\u636e\u662f\u5426\u51fa\u73b0\u5728\u4e3b\u8868\u4e2d\u3002\u4e3a\u6b64\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8be2\uff1a<\/p>\n<pre>SELECT *\nFROM (\n    SELECT pn_Code, serialNumber\n    FROM pnassertbasic_ruku pr\n    LEFT JOIN pnassertruku pu ON pr.parent_pnAssertRuku_id = pu.child_pnAssertRukuDetails_id\n    WHERE pn_Code IS NOT NULL AND serialNumber IS NOT NULL AND DATE(pr.create_time) = CURDATE() AND pr.warehouseEntryNumber &lt;&gt; 'WEd3791f0b'\n) AS temp1\nWHERE EXISTS (\n    SELECT *\n    FROM (\n        SELECT pn_Code, serialNumber\n        FROM pnassertbasic_ruku pr\n        LEFT JOIN pnassertruku pu ON pr.parent_pnAssertRuku_id = pu.child_pnAssertRukuDetails_id\n        WHERE pu.child_pnAssertRukuDetails_id IS NULL AND pr.warehouseEntryNumber = 'WEd3791f0b'\n    ) AS temp2\n    WHERE temp1.pn_Code = temp2.pn_Code AND temp1.serialNumber = temp2.serialNumber\n)<\/pre>\n<p>\u6b64\u67e5\u8be2\u5c06\u9996\u5148\u4ece\u4e3b\u8868\u4e2d\u9009\u62e9 pn_code \u548c serialnumber\uff0c\u518d\u4ece\u5b50\u8868\u4e2d\u9009\u62e9\u76f8\u540c\u7684\u5b57\u6bb5\u3002\u7136\u540e\uff0c\u5b83\u4f7f\u7528 exists \u5b50\u67e5\u8be2\u6765\u68c0\u67e5\u4e3b\u8868\u4e2d\u7684\u6bcf\u6761\u8bb0\u5f55\u5728\u5b50\u8868\u4e2d\u662f\u5426\u5b58\u5728\u5bf9\u5e94\u7684\u8bb0\u5f55\u3002\u5982\u679c\u5b58\u5728\uff0cexists \u5c06\u8fd4\u56de true\uff0c\u5e76\u663e\u793a\u4e3b\u8868\u8bb0\u5f55\uff1b\u5426\u5219\uff0cexists \u5c06\u8fd4\u56de false\uff0c\u4e3b\u8868\u8bb0\u5f55\u5c06\u88ab\u8fc7\u6ee4\u6389\u3002<\/p>\n<p><strong>\u6ce8\u610f\uff1a<\/strong>\u786e\u4fdd\u4f60\u7684\u67e5\u8be2\u8bed\u6cd5\u6b63\u786e\u3002\u4f60\u5c06 selet \u800c\u4e0d\u662f select \u4f5c\u4e3a exists \u5b50\u67e5\u8be2\u7684\u7b2c\u4e00\u4e2a\u5355\u8bcd\u62fc\u5199\u9519\u8bef\u3002<\/p>\n<p>\u4ee5\u4e0a\u5c31\u662f\u300a\u5982\u4f55\u5728 MySQL \u67e5\u8be2\u4e2d\u5229\u7528 EXISTS \u5173\u952e\u8bcd\u68c0\u67e5\u4e24\u4e2a\u8868\u4e2d\u662f\u5426\u5b58\u5728\u5bf9\u5e94\u503c\uff1f\u300b\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u5173\u4e8e\u7684\u8d44\u6599\u8bf7\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff01<\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>\u5982\u4f55\u5728 MySQL \u67e5\u8be2\u4e2d\u5229\u7528 &#46;&#46;&#46;<\/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-201053","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/201053","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=201053"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/201053\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=201053"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=201053"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=201053"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}