{"id":207174,"date":"2025-07-08T08:31:36","date_gmt":"2025-07-08T00:31:36","guid":{"rendered":"https:\/\/server.hk\/cnblog\/207174\/"},"modified":"2025-07-08T08:31:36","modified_gmt":"2025-07-08T00:31:36","slug":"%e5%a6%82%e4%bd%95%e8%8e%b7%e5%8f%96gorm%e6%a8%a1%e5%9e%8b%e7%9a%84%e8%ae%a1%e7%ae%97%e5%80%bc%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/207174\/","title":{"rendered":"\u5982\u4f55\u83b7\u53d6GORM\u6a21\u578b\u7684\u8ba1\u7b97\u503c\uff1f"},"content":{"rendered":"

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

\u5f53\u524d\u4f4d\u7f6e\uff1a ><\/span> ><\/span> ><\/span> ><\/span> \u5982\u4f55\u83b7\u53d6GORM\u6a21\u578b\u7684\u8ba1\u7b97\u503c\uff1f<\/span><\/p>\n

\u6765\u6e90\uff1astackoverflow<\/span>
\n2024-04-20 16:19:13<\/span>
\n<\/i>0\u6d4f\u89c8<\/span>
\n<\/i>\u6536\u85cf<\/span> <\/p>\n

\u672c\u7bc7\u6587\u7ae0\u4e3b\u8981\u662f\u7ed3\u5408\u6211\u4e4b\u524d\u9762\u8bd5\u7684\u5404\u79cd\u7ecf\u5386\u548c\u5b9e\u6218\u5f00\u53d1\u4e2d\u9047\u5230\u7684\u95ee\u9898\u89e3\u51b3\u7ecf\u9a8c\u6574\u7406\u7684\uff0c\u5e0c\u671b\u8fd9\u7bc7\u300a\u5982\u4f55\u83b7\u53d6GORM\u6a21\u578b\u7684\u8ba1\u7b97\u503c\uff1f\u300b\u5bf9\u4f60\u6709\u5f88\u5927\u5e2e\u52a9\uff01\u6b22\u8fce\u6536\u85cf\uff0c\u5206\u4eab\u7ed9\u66f4\u591a\u7684\u9700\u8981\u7684\u670b\u53cb\u5b66\u4e60~<\/p>\n

\u95ee\u9898\u5185\u5bb9
\n <\/p>\n

\u6240\u4ee5\uff0c\u6211\u6709\u4e00\u4e2a\u975e\u5e38\u7b80\u5355\u7684\u67e5\u8be2\uff0c\u6211\u53ef\u4ee5\u5728 gorm \u4e2d\u6a21\u62df\u5b83\uff0c\u4f46\u73b0\u5728\u6211\u65e0\u6cd5\u8bfb\u53d6\u6a21\u578b\u7684\u6240\u6709\u503c\uff1a<\/p>\n

select e.employee_id, e.first_name ,\n(select count(*) < 1 from other_table ot where ot.employee_id = e.id) as isbelowone\nfrom employees e ;\n<\/pre>\n
\u6240\u4ee5\u95ee\u9898\u662f isblowone<\/code> \u662f\u4e00\u4e2a\u8ba1\u7b97\u503c\uff0c\u6211\u4e0d\u60f3\u5b58\u50a8\u5728\u8868\u4e0a\uff0c\u800c\u662f\u4ece\u5b50\u67e5\u8be2\u4e2d\u8ba1\u7b97\u5b83\u3002 \u8fd9\u5c31\u662f\u6211\u6784\u5efa\u5b50\u67e5\u8be2\u7684\u65b9\u5f0f\uff1a<\/p>\n
    subquery := r.DB.\n                  Table(\"other_table\").\n                  Select(\"count(*) < 1\").\n                  Where(\"other_table.employee_id = employees.id\").SubQuery()\n\n    sql = sql.Select(\"*, ? as isBelowOne\", subquery)\n\n<\/pre>\n
\u6211\u73b0\u5728\u7684\u95ee\u9898\u662f\u8ba9 gorm \u8bfb\u53d6\u8be5\u5b57\u6bb5\u3002\u6211\u65e0\u6cd5\u5c06\u5176\u58f0\u660e\u4e3a\u6a21\u578b\u7684\u4e00\u90e8\u5206\uff0c\u56e0\u4e3a\u6211\u4e0d\u60f3\u5c06\u5176\u4fdd\u7559\u5728\u6570\u636e\u5e93\u4e2d\uff0c\u90a3\u4e48\u6709\u4ec0\u4e48\u9009\u62e9\u5462\uff1f \u6211\u5728\u9ad8\u7ea7\u67e5\u8be2\u4e2d\u6ca1\u6709\u627e\u5230\u4efb\u4f55\u5173\u4e8e\u6b64\u7684\u4fe1\u606f\uff0c\u4ed6\u4eec\u6240\u8c13\u7684\u9ad8\u7ea7\u53ea\u662f\u6392\u5e8f\u548c\u6761\u4ef6\uff0c\u6ca1\u6709\u8fd9\u6837\u7684\u3002<\/p>\n
 <\/p>\n
\u89e3\u51b3\u65b9\u6848<\/h2>\n
 <\/p>\n
\u8fd9\u662f\u6211\u60f3\u51fa\u7684\u89e3\u51b3\u65b9\u6848\u3002 \u9996\u5148\u8981\u4fee\u590d\u7684\u662f\u67e5\u8be2\u4e2d\u7684\u5b57\u6bb5\u540d\u79f0\u3002\u6309\u7167\u60ef\u4f8b\uff0cgorm \u8981\u6c42\u60a8\u5728\u5b57\u6bb5\u4e0a\u4f7f\u7528 snake_case\uff0c\u56e0\u6b64\u8fd9\u662f\u6267\u884c\u67e5\u8be2\u7684\u6b63\u786e\u65b9\u6cd5\uff1a<\/p>\n
sql = sql.select(\"*, ? as is_below_one\", subquery)\n<\/pre>\n
\u7136\u540e\uff0c\u53ea\u9700\u5728\u6a21\u578b\u4e0a\u58f0\u660e\u8be5\u5b57\u6bb5\uff0c\u4f46\u8ba9 gorm \u5ffd\u7565\u5b83\uff1a<\/p>\n
IsBelowOne  bool `gorm:\"-\"`\n<\/pre>\n
\u6839\u636e\u6587\u6863\uff0c\u8fd9\u88ab\u79f0\u4e3a \uff0c\u4f46\u4ee4\u4eba\u56f0\u60d1\u7684\u662f\uff0c\u5b83\u8bf4 gorm:\"-\"<\/code> \u4f1a\u8ba9 gorm \u5728\u5199\u5165\u548c\u8bfb\u53d6\u65f6\u5ffd\u7565\u5b83\uff0c\u4f7f\u5176\u51e0\u4e4e\u6beb\u65e0\u7528\u5904\u3002\u7136\u800c\uff0c\u5728\u5b9e\u8df5\u4e2d\u5b83\u662f\u6709\u6548\u7684\uff0c\u6240\u4ee5\u6211\u60f3\u8fd9\u53ea\u662f\u7cdf\u7cd5\u7684\u6587\u6863\u3002<\/p>\n
\u4eca\u5929\u5e26\u5927\u5bb6\u4e86\u89e3\u4e86\u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u5e0c\u671b\u5bf9\u4f60\u6709\u6240\u5e2e\u52a9\uff1b\u5173\u4e8eGolang\u7684\u6280\u672f\u77e5\u8bc6\u6211\u4eec\u4f1a\u4e00\u70b9\u70b9\u6df1\u5165\u4ecb\u7ecd\uff0c\u6b22\u8fce\u5927\u5bb6\u5173\u6ce8\u516c\u4f17\u53f7\uff0c\u4e00\u8d77\u5b66\u4e60\u7f16\u7a0b~<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5f53\u524d\u4f4d\u7f6e\uff1a > > ...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-207174","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/207174","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=207174"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/207174\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=207174"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=207174"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=207174"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}