LinqPad 可以Load一个包含有EF Model的程序集。这样极大的方便调试LINQ.而不需要VisualStudio， 让我们来演示一下。首选创建一个Connection，看下图：
通过点击Browse加载一个程序集，然后你可以看左右的目录树结构：
输入这样的LINQ Expression:
1: from forumGroupMapping in ForumGroupMappings
2: join forumGroup in ForumGroups
3: on forumGroupMapping.ForumGroupId equals forumGroup.Id 4: 5: join teamForumGroupMapping in TeamForumGroupMappingAccesses
6: on forumGroupMapping.Id equals teamForumGroupMapping.ForumGroupMappingId 7: 8: join teamRole in TeamRoleAgentMappings
9: on teamForumGroupMapping.TeamId equals teamRole.TeamId 10: 11: join team in Teams
12: on teamRole.TeamId equals team.Id 13: 14: where team.IsActive.Equals(true) &&
15: team.IsDeleted.Equals(false) &&
16: teamRole.IsActive.Equals(true) &&
17: teamRole.IsDeleted.Equals(false) &&
18: teamForumGroupMapping.IsActive.Equals(true) &&
19: teamForumGroupMapping.IsDeleted.Equals(false) &&
20: forumGroupMapping.IsActive.Equals(true) &&
21: forumGroupMapping.IsDeleted.Equals(false) &&
22: forumGroup.IsActive.Equals(true) &&
23: forumGroup.IsActive.Equals(true) &&
24: teamRole.AgentId.Equals(new Guid("476c261f-b25a-4c0b-ba06-f3c9f7b00eeb"))
25: select forumGroupMapping执行后可以看到这个T-SQL：
1: SELECT
2: [Filter2].[Id1] AS [Id],
3: [Filter2].[ForumGroupId] AS [ForumGroupId],
4: [Filter2].[ForumId] AS [ForumId],
5: [Filter2].[RootForumId] AS [RootForumId],
6: [Filter2].[RootForumExternalId] AS [RootForumExternalId],
7: [Filter2].[PlatformTypeId] AS [PlatformTypeId],
8: [Filter2].[Locale] AS [Locale],
9: [Filter2].[CreatedBy1] AS [CreatedBy],
10: [Filter2].[CreatedDate1] AS [CreatedDate],
11: [Filter2].[LastUpdatedBy1] AS [LastUpdatedBy],
12: [Filter2].[LastUpdatedDate1] AS [LastUpdatedDate],
13: [Filter2].[IsActive1] AS [IsActive],
14: [Filter2].[IsDeleted1] AS [IsDeleted]
15: FROM (SELECT [Filter1].[Id1], [Filter1].[ForumGroupId], [Filter1].[ForumId], [Filter1].[RootForumId], [Filter1].[RootForumExternalId], [Filter1].[PlatformTypeId], [Filter1].[Locale], [Filter1].[CreatedBy1], [Filter1].[CreatedDate1], [Filter1].[LastUpdatedBy1], [Filter1].[LastUpdatedDate1], [Filter1].[IsActive1], [Filter1].[IsDeleted1], [Filter1].[TeamId1], [Extent4].[TeamId] AS [TeamId2]
16: FROM (SELECT [Extent1].[Id] AS [Id1], [Extent1].[ForumGroupId] AS [ForumGroupId], [Extent1].[ForumId] AS [ForumId], [Extent1].[RootForumId] AS [RootForumId], [Extent1].[RootForumExternalId] AS [RootForumExternalId], [Extent1].[PlatformTypeId] AS [PlatformTypeId], [Extent1].[Locale] AS [Locale], [Extent1].[CreatedBy] AS [CreatedBy1], [Extent1].[CreatedDate] AS [CreatedDate1], [Extent1].[LastUpdatedBy] AS [LastUpdatedBy1], [Extent1].[LastUpdatedDate] AS [LastUpdatedDate1], [Extent1].[IsActive] AS [IsActive1], [Extent1].[IsDeleted] AS [IsDeleted1], [Extent3].[TeamId] AS [TeamId1]
17: FROM [dbo].[ForumGroupMapping] AS [Extent1]
18: INNER JOIN [dbo].[ForumGroup] AS [Extent2] ON [Extent1].[ForumGroupId] = [Extent2].[Id]
19: INNER JOIN [dbo].[TeamForumGroupMappingAccess] AS [Extent3] ON [Extent1].[Id] = [Extent3].[ForumGroupMappingId]
20: WHERE (1 = [Extent1].[IsActive]) AND (0 = [Extent1].[IsDeleted]) AND (1 = [Extent2].[IsActive]) AND (1 = [Extent2].[IsActive]) AND (1 = [Extent3].[IsActive]) AND (0 = [Extent3].[IsDeleted]) ) AS [Filter1]
21: INNER JOIN [dbo].[TeamRoleAgentMapping] AS [Extent4] ON [Filter1].[TeamId1] = [Extent4].[TeamId]
22: WHERE (1 = [Extent4].[IsActive]) AND (0 = [Extent4].[IsDeleted]) AND (cast('476c261f-b25a-4c0b-ba06-f3c9f7b00eeb' as uniqueidentifier) = [Extent4].[AgentId]) ) AS [Filter2]
23: INNER JOIN [dbo].[Team] AS [Extent5] ON [Filter2].[TeamId2] = [Extent5].[Id]
24: WHERE (1 = [Extent5].[IsActive]) AND (0 = [Extent5].[IsDeleted])
同时你可以查看这个查询生成IL。这里就不截图了。
LINQPad 支持 C# 4.0 和 Framework 4.0 :
- LINQ to Objects
- LINQ to SQL and Entity Framework
- LINQ to XML
- Parallel LINQ
您还能查询:
- OData / WCF Data Services - including StackOverflow, and Windows DataMarket
- SQL Azure, Oracle, SQLite and MySQL
- Microsoft StreamInsight
- Microsoft Dynamics CRM
- Mindscape LightSpeed ORM
- (Even old-fashioned SQL!)
希望这篇POST对您开发有帮助。
作者：Petter Liu
出处：http://www.cnblogs.com/wintersun/
本文版权归作者和博客园共有，欢迎转载，但未经作者同意必须保留此段声明，且在文章页面明显位置给出原文连接，否则保留追究法律责任的权利。
该文章也同时发布在我的独立博客中-Petter Liu Blog。