{"id":2880,"date":"2015-04-12T09:16:38","date_gmt":"2015-04-12T01:16:38","guid":{"rendered":"http:\/\/leybreeze.com\/blog\/?p=2880"},"modified":"2015-04-12T09:16:38","modified_gmt":"2015-04-12T01:16:38","slug":"net-%e4%b8%ad-entity-framework-%e7%9a%84%e6%95%b0%e6%8d%ae%e5%ba%93%e6%9f%a5%e8%af%a2","status":"publish","type":"post","link":"http:\/\/leybreeze.com\/blog\/?p=2880","title":{"rendered":".NET \u4e2d Entity Framework \u7684\u6570\u636e\u5e93\u67e5\u8be2"},"content":{"rendered":"<p>Entity Framework \u652f\u6301\u4e09\u79cd\u7c7b\u578b\u7684\u6570\u636e\u5e93\u67e5\u8be2\u3002<\/p>\n<ul>\n<li>LINQ to Entities<\/li>\n<li>Entity SQL<\/li>\n<li>Native SQL<\/li>\n<\/ul>\n<p>\u5176\u4e2d\uff0cLINQ\uff08\u97f3\uff1alink\uff09\u662f\u8f83\u4e3a\u63a8\u8350\u7684\u65b9\u5f0f\u3002\u5b83\u53c8\u5206\u4e3a LINQ Method syntax \u4e0e LINQ Query syntax\uff0c\u5982\u4e0b\u6240\u793a\u3002<\/p>\n<pre lang=\"CSharp\">\/\/ LINQ Method syntax\r\nusing (var context = new CompanyDBEntities()) \r\n{ \r\n    var L2EQuery = context.Employees.where(e =&gt; e.EmployeeName== \"Ben\"); \r\n    var employee= L2EQuery.FirstOrDefault(); \r\n} \r\n\r\n\/\/ LINQ Query syntax\r\nusing (var context = new CompanyDBEntities()) \r\n{ \r\n    var L2EQuery = from ep in context.Employees    \r\n                   where ep.EmployeeName == \"Bill\" \r\n                   select ep; \r\n     var employee = L2EQuery.FirstOrDefault(); \r\n} \r\n<\/pre>\n<p>Entity SQL \u4e0e Native SQL \u90fd\u662f\u57fa\u4e8e\u62fc\u63a5 SQL \u8bed\u53e5\u7684\u65b9\u5f0f\uff0c\u5982\u4e0b\u6240\u793a\u3002<\/p>\n<pre lang=\"CSharp\">\/\/ Entity SQL\r\nstring sqlString = \"SELECT VALUE ep FROM CompanyDBEntities.Employees \" + \"AS ep WHERE ep.EmployeeName == 'Ben'\"; \r\nvar objctx = (ctx as IObjectContextAdapter).ObjectContext; \r\nObjectQuery employee = objctx.CreateQuery(sqlString); \r\nEmployee newEmployee = employee.First(); \r\n\r\n\/\/ Native SQL\r\nusing (var ctx = new CompanyDBEntities()) \r\n{ \r\n    var employeeName = ctx.Employees.SqlQuery(\"Select EmployeeId, EmployeeName from Employee where EmployeeName='Ben'\").FirstOrDefault(); \r\n} \r\n<\/pre>\n<p>\u6b64\u5916\uff0cEntity Framework \u63d0\u4f9b\u4e86\u4e30\u5bcc\u7684\u51fd\u6570\uff0c\u5e94\u4e86\u89e3\u5e76\u638c\u63e1\u7528\u6cd5\u3002\u4ee5\u4e0b\u5217\u4e3e\u4e00\u4e9b\u3002<\/p>\n<ul>\n<li>Aggregate*<\/li>\n<li>Average<\/li>\n<li>All<\/li>\n<li>Any<\/li>\n<li>ElementAt\/ElementAtOrDefault*<\/li>\n<li>Single\/SingleOrDefault*<\/li>\n<li>Contains<\/li>\n<li>First\/FirstOrDefault\/Last\/LastOrDefault*<\/li>\n<li>Count<\/li>\n<li>Max\/Min*<\/li>\n<li>OrderBy\/OrderByDescending<\/li>\n<li>Reverse<\/li>\n<li>SelectMany<\/li>\n<li>SequenceEqual<\/li>\n<li>Skip\/SkipWhile<\/li>\n<li>Take\/TakeWhile<\/li>\n<\/ul>\n<p>\u5176\u4e2d\u4ee5\u661f\u53f7\u6807\u8bb0\u7684\u5c06\u8fd4\u56de Entity \u5b9e\u4f53\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Entity Framework \u652f\u6301\u4e09\u79cd\u7c7b\u578b\u7684\u6570\u636e\u5e93\u67e5\u8be2\u3002 LINQ to Entities Entity  &hellip; <a href=\"http:\/\/leybreeze.com\/blog\/?p=2880\" class=\"more-link\">\u7ee7\u7eed\u9605\u8bfb<span class=\"screen-reader-text\">\u201c.NET \u4e2d Entity Framework \u7684\u6570\u636e\u5e93\u67e5\u8be2\u201d<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[138],"tags":[139,140],"_links":{"self":[{"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2880"}],"collection":[{"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2880"}],"version-history":[{"count":1,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2880\/revisions"}],"predecessor-version":[{"id":2881,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2880\/revisions\/2881"}],"wp:attachment":[{"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2880"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2880"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2880"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}