{"id":183696,"date":"2024-11-10T06:58:21","date_gmt":"2024-11-09T22:58:21","guid":{"rendered":"https:\/\/server.hk\/cnblog\/183696\/"},"modified":"2024-11-10T06:58:22","modified_gmt":"2024-11-09T22:58:22","slug":"%e4%bd%bf%e7%94%a8ef%e6%a1%86%e6%9e%b6%e5%af%a6%e7%8f%be%e5%a4%9a%e6%95%b8%e6%93%9a%e5%ba%ab%e6%a2%9d%e4%bb%b6%e6%9f%a5%e8%a9%a2-ef%e6%a1%86%e6%9e%b6%e6%a2%9d%e4%bb%b6%e6%9f%a5%e8%a9%a2%e5%a4%9a","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/183696\/","title":{"rendered":"\u4f7f\u7528EF\u6846\u67b6\u5be6\u73fe\u591a\u6578\u64da\u5eab\u689d\u4ef6\u67e5\u8a62 (ef\u6846\u67b6\u689d\u4ef6\u67e5\u8a62\u591a\u500b\u6578\u64da\u5eab)"},"content":{"rendered":"<h1 id=\"%e4%bd%bf%e7%94%a8ef%e6%a1%86%e6%9e%b6%e5%af%a6%e7%8f%be%e5%a4%9a%e6%95%b8%e6%93%9a%e5%ba%ab%e6%a2%9d%e4%bb%b6%e6%9f%a5%e8%a9%a2-PaustkGmHH\">\u4f7f\u7528EF\u6846\u67b6\u5be6\u73fe\u591a\u6578\u64da\u5eab\u689d\u4ef6\u67e5\u8a62<\/h1>\n<p>\u5728\u73fe\u4ee3\u61c9\u7528\u7a0b\u5e8f\u958b\u767c\u4e2d\uff0c\u6578\u64da\u5eab\u7684\u4f7f\u7528\u8b8a\u5f97\u8d8a\u4f86\u8d8a\u666e\u904d\u3002\u96a8\u8457\u696d\u52d9\u9700\u6c42\u7684\u589e\u9577\uff0c\u958b\u767c\u8005\u7d93\u5e38\u9700\u8981\u5f9e\u591a\u500b\u6578\u64da\u5eab\u4e2d\u9032\u884c\u67e5\u8a62\u3002Entity Framework\uff08EF\uff09\u4f5c\u70ba\u4e00\u500b\u5f37\u5927\u7684ORM\uff08\u5c0d\u8c61\u95dc\u4fc2\u6620\u5c04\uff09\u6846\u67b6\uff0c\u63d0\u4f9b\u4e86\u4fbf\u6377\u7684\u65b9\u5f0f\u4f86\u9032\u884c\u6578\u64da\u64cd\u4f5c\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5982\u4f55\u4f7f\u7528EF\u6846\u67b6\u5be6\u73fe\u591a\u6578\u64da\u5eab\u7684\u689d\u4ef6\u67e5\u8a62\uff0c\u4e26\u63d0\u4f9b\u76f8\u95dc\u7684\u793a\u4f8b\u548c\u4ee3\u78bc\u7247\u6bb5\u3002<\/p>\n<h2 id=\"ef%e6%a1%86%e6%9e%b6%e7%b0%a1%e4%bb%8b-PaustkGmHH\">EF\u6846\u67b6\u7c21\u4ecb<\/h2>\n<p>Entity Framework\u662f\u4e00\u500b\u7531\u5fae\u8edf\u958b\u767c\u7684ORM\u6846\u67b6\uff0c\u65e8\u5728\u7c21\u5316\u6578\u64da\u5eab\u64cd\u4f5c\u3002\u5b83\u5141\u8a31\u958b\u767c\u8005\u4f7f\u7528.NET\u5c0d\u8c61\u4f86\u64cd\u4f5c\u6578\u64da\u5eab\uff0c\u800c\u4e0d\u9700\u8981\u76f4\u63a5\u7de8\u5bebSQL\u8a9e\u53e5\u3002EF\u652f\u6301LINQ\u67e5\u8a62\uff0c\u9019\u4f7f\u5f97\u67e5\u8a62\u8a9e\u53e5\u66f4\u52a0\u76f4\u89c0\u548c\u6613\u65bc\u7dad\u8b77\u3002<\/p>\n<h2 id=\"%e5%a4%9a%e6%95%b8%e6%93%9a%e5%ba%ab%e6%9f%a5%e8%a9%a2%e7%9a%84%e9%9c%80%e6%b1%82-PaustkGmHH\">\u591a\u6578\u64da\u5eab\u67e5\u8a62\u7684\u9700\u6c42<\/h2>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u61c9\u7528\u7a0b\u5e8f\u53ef\u80fd\u9700\u8981\u5f9e\u591a\u500b\u6578\u64da\u5eab\u4e2d\u7372\u53d6\u6578\u64da\u3002\u4f8b\u5982\uff0c\u4f01\u696d\u53ef\u80fd\u6703\u5c07\u4e0d\u540c\u7684\u696d\u52d9\u908f\u8f2f\u5206\u6563\u5230\u4e0d\u540c\u7684\u6578\u64da\u5eab\u4e2d\uff0c\u6216\u8005\u5728\u4e0d\u540c\u7684\u74b0\u5883\u4e2d\uff08\u5982\u958b\u767c\u3001\u6e2c\u8a66\u548c\u751f\u7522\uff09\u4f7f\u7528\u4e0d\u540c\u7684\u6578\u64da\u5eab\u3002\u9019\u6642\uff0c\u958b\u767c\u8005\u9700\u8981\u80fd\u5920\u9748\u6d3b\u5730\u5f9e\u9019\u4e9b\u6578\u64da\u5eab\u4e2d\u9032\u884c\u67e5\u8a62\u3002<\/p>\n<h2 id=\"%e8%a8%ad%e7%bd%ae%e5%a4%9a%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%8a%e4%b8%8b%e6%96%87-PaustkGmHH\">\u8a2d\u7f6e\u591a\u6578\u64da\u5eab\u4e0a\u4e0b\u6587<\/h2>\n<p>\u5728EF\u4e2d\uff0c\u6bcf\u500b\u6578\u64da\u5eab\u901a\u5e38\u5c0d\u61c9\u4e00\u500bDbContext\u3002\u8981\u5be6\u73fe\u591a\u6578\u64da\u5eab\u67e5\u8a62\uff0c\u9996\u5148\u9700\u8981\u70ba\u6bcf\u500b\u6578\u64da\u5eab\u5275\u5efa\u4e00\u500bDbContext\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>public class DatabaseAContext : DbContext\n{\n    public DatabaseAContext() : base(\"name=DatabaseAConnectionString\") { }\n\n    public DbSet&lt;EntityA&gt; EntitiesA { get; set; }\n}\n\npublic class DatabaseBContext : DbContext\n{\n    public DatabaseBContext() : base(\"name=DatabaseBConnectionString\") { }\n\n    public DbSet&lt;EntityB&gt; EntitiesB { get; set; }\n}\n<\/code><\/pre>\n<h2 id=\"%e5%9f%b7%e8%a1%8c%e5%a4%9a%e6%95%b8%e6%93%9a%e5%ba%ab%e6%9f%a5%e8%a9%a2-PaustkGmHH\">\u57f7\u884c\u591a\u6578\u64da\u5eab\u67e5\u8a62<\/h2>\n<p>\u4e00\u65e6\u8a2d\u7f6e\u4e86\u591a\u500bDbContext\uff0c\u5c31\u53ef\u4ee5\u5728\u61c9\u7528\u7a0b\u5e8f\u4e2d\u9032\u884c\u67e5\u8a62\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u5f9e\u5169\u500b\u4e0d\u540c\u7684\u6578\u64da\u5eab\u4e2d\u67e5\u8a62\u6578\u64da\uff1a<\/p>\n<pre><code>using (var contextA = new DatabaseAContext())\nusing (var contextB = new DatabaseBContext())\n{\n    var queryA = contextA.EntitiesA.Where(e =&gt; e.Condition == true).ToList();\n    var queryB = contextB.EntitiesB.Where(e =&gt; e.Condition == true).ToList();\n\n    var combinedResults = queryA.Concat(queryB).ToList();\n}\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u793a\u4f8b\u4e2d\uff0c\u6211\u5011\u9996\u5148\u5275\u5efa\u4e86\u5169\u500bDbContext\u7684\u5be6\u4f8b\uff0c\u7136\u5f8c\u5f9e\u6bcf\u500b\u6578\u64da\u5eab\u4e2d\u67e5\u8a62\u7b26\u5408\u689d\u4ef6\u7684\u6578\u64da\u3002\u6700\u5f8c\uff0c\u6211\u5011\u4f7f\u7528LINQ\u7684Concat\u65b9\u6cd5\u5c07\u5169\u500b\u67e5\u8a62\u7684\u7d50\u679c\u5408\u4f75\u3002<\/p>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-PaustkGmHH\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<ul>\n<li>\u6027\u80fd\uff1a\u5f9e\u591a\u500b\u6578\u64da\u5eab\u4e2d\u67e5\u8a62\u53ef\u80fd\u6703\u5f71\u97ff\u6027\u80fd\uff0c\u7279\u5225\u662f\u5728\u6578\u64da\u91cf\u8f03\u5927\u7684\u60c5\u6cc1\u4e0b\u3002\u5efa\u8b70\u5c0d\u67e5\u8a62\u9032\u884c\u512a\u5316\u3002<\/li>\n<li>\u4e8b\u52d9\u7ba1\u7406\uff1a\u5728\u591a\u6578\u64da\u5eab\u64cd\u4f5c\u4e2d\uff0c\u4e8b\u52d9\u7ba1\u7406\u8b8a\u5f97\u66f4\u52a0\u8907\u96dc\u3002\u9700\u8981\u8003\u616e\u5982\u4f55\u5728\u4e0d\u540c\u7684\u6578\u64da\u5eab\u4e4b\u9593\u4fdd\u6301\u6578\u64da\u4e00\u81f4\u6027\u3002<\/li>\n<li>\u9023\u63a5\u5b57\u7b26\u4e32\uff1a\u78ba\u4fdd\u5728\u914d\u7f6e\u6587\u4ef6\u4e2d\u6b63\u78ba\u8a2d\u7f6e\u6bcf\u500b\u6578\u64da\u5eab\u7684\u9023\u63a5\u5b57\u7b26\u4e32\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-PaustkGmHH\">\u7e3d\u7d50<\/h2>\n<p>\u4f7f\u7528EF\u6846\u67b6\u5be6\u73fe\u591a\u6578\u64da\u5eab\u689d\u4ef6\u67e5\u8a62\u662f\u4e00\u500b\u5f37\u5927\u4e14\u9748\u6d3b\u7684\u89e3\u6c7a\u65b9\u6848\u3002\u901a\u904e\u8a2d\u7f6e\u591a\u500bDbContext\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u8f15\u9b06\u5730\u5f9e\u4e0d\u540c\u7684\u6578\u64da\u5eab\u4e2d\u7372\u53d6\u6578\u64da\uff0c\u4e26\u9032\u884c\u5408\u4f75\u548c\u8655\u7406\u3002\u9019\u7a2e\u65b9\u6cd5\u4e0d\u50c5\u63d0\u9ad8\u4e86\u958b\u767c\u6548\u7387\uff0c\u9084\u80fd\u5920\u6eff\u8db3\u8907\u96dc\u7684\u696d\u52d9\u9700\u6c42\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u4f86\u90e8\u7f72\u60a8\u7684\u61c9\u7528\u7a0b\u5e8f\uff0c\u9019\u5c07\u70ba\u60a8\u7684\u6578\u64da\u5eab\u64cd\u4f5c\u63d0\u4f9b\u7a69\u5b9a\u7684\u74b0\u5883\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4f7f\u7528EF\u6846\u67b6\u5be6\u73fe\u591a\u6578\u64da\u5eab\u689d\u4ef6\u67e5\u8a62\uff0c\u8f15\u9b06\u7ba1\u7406\u548c\u67e5\u8a62\u591a\u500b\u6578\u64da\u5eab\u4e2d\u7684\u6578\u64da\uff0c\u63d0\u5347\u958b\u767c\u6548\u7387\u8207\u9748\u6d3b\u6027\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-183696","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/183696","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"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=183696"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/183696\/revisions"}],"predecessor-version":[{"id":183697,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/183696\/revisions\/183697"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=183696"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=183696"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=183696"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}