SELECT    CV2.CV_CODE as CODE, CV1.CV_CODE as VALUE, CV2.CV_CONTENT+CV1.CV_CONTENT as CONTENT
                    FROM [RiverEarth].[dbo].[CodeValue] as CV1,
                            (
                                SELECT [CV_CODE]
                                      ,[CV_CONTENT]
                                FROM [RiverEarth].[dbo].[CodeValue]
                                where CV_CODE LIKE '0003%' --表示海堤
                                AND LEN(CV_CODE)=12
                            ) as CV2
                    where CV1.CV_CODE LIKE CV2.CV_CODE+'%'
                    AND LEN(CV1.CV_CODE)=16

if exists (select * from sysobjects where id = OBJECT_ID('[CodeValue]') and OBJECTPROPERTY(id, 'IsUserTable') = 1) 
DROP TABLE [CodeValue]

CREATE TABLE [CodeValue] (
[CV_TYPE] [char]  (4) NOT NULL,
[CV_CODE] [varchar]  (40) NOT NULL,
[CV_CONTENT] [nvarchar]  (100) NULL,
[CV_UNAME] [nvarchar]  (20) NULL,
[CV_UDATE] [char]  (14) NULL)

ALTER TABLE [CodeValue] WITH NOCHECK ADD  CONSTRAINT [PK_CodeValue] PRIMARY KEY  NONCLUSTERED ( [CV_CODE] )
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0001',N'00010001',N'發現災情，處理中',N'admin',N'201109221742')
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0001',N'00010002',N'未發現災情，監控中',N'admin',N'201109221742')
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0001',N'00010003',N'已完成巡視，無災情',N'admin',N'201109221742')
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0002',N'00020001',N'檢查各項目及結果',N'admin',N'201109221742')
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0002',N'000200010001',N'堤頂',N'admin',N'201109221742')
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0002',N'0002000100010001',N'沉陷',N'admin',N'201109221742')
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0002',N'0002000100010002',N'裂縫',N'admin',N'201109221742')
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0002',N'0002000100010003',N'崩裂',N'admin',N'201109221742')
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0002',N'0002000100010004',N'正常',N'admin',N'201109221742')
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0002',N'000200010002',N'前坡',N'admin',N'201109221742')
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0002',N'0002000100020001',N'沉陷',N'admin',N'201109221742')
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0002',N'0002000100020002',N'裂縫',N'admin',N'201109221742')
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0002',N'0002000100020003',N'崩裂',N'admin',N'201109221742')
INSERT [CodeValue] ([CV_TYPE],[CV_CODE],[CV_CONTENT],[CV_UNAME],[CV_UDATE]) VALUES ( N'0002',N'0002000100020004',N'正常',N'admin',N'201109221742')

//又见如此好的提问方式，赞一个
var query=from cv1 in db.CodeValue
          let temp=from c in db.CodeValue
                   where c.CV_CODE.EndWith("0003")
                         && c.CV_CODE.Length==12
                   select new {c.CV_CODE,c.CV_CONTENT}
          from cv2 in temp
          where cv1.CV_CODE.EndWith(CV2.CV_CODE)
               && cv1.CV_CODE.Length==16
          select new 
          {
               CODE=cv2.CV_CODE,
               VALUE=cv1.CV_CODE,
               CONTENT=cv2.CV_CONTENT+cv1.CV_CONTENT 
           };

------解决方案--------------------
对数据源加上 .ToList() 方法就可以调用了.