SQL Server 2005 Hierarchical Data concatenation

Question

Hi Folks,
Please help me on the following data concatenation using hierarchical Query
Table Data:
Level Id     ParentTbl     PatCol
    ChildTbl    ChildCol    
1                  
A                 
a          
B            b
1                  
A                  a           C            c
2             
     C                  c           D            d
3                  
D                  d           E            e        
Excepted Result:
Level Id     ParentTbl     PatCol
    ChildTbl    ChildCol         SQLString
1                  
A                 
a          
B            b            A.a =B.b
1                  
A                  a           C            c            A.a
= C.c
2             
     C                  c           D            d      
     A.a = C.c =D.d
3                  
D                  d           E            e           
A.a = C.c = D.d =E.e  
Thanks
Narendran 
Narendran

Answer 1

Declare @SampleData Table ([Level Id] int, ParentTbl varchar(256), PatCol varchar(256), ChildTbl varchar(256), ChildCol varchar(256));   
Insert @SampleData([Level Id], ParentTbl, PatCol, ChildTbl, ChildCol)
Select 1,                   'A',                  'a',           'B',            'b'
Union All Select 1,                   'A',                  'a',           'C',            'c'
Union All Select 2,                   'C',                  'c',           'D',            'd'
Union All Select 3,                   'D',                  'd',           'E',            'e';
;With cte As
(Select [Level Id], ParentTbl, PatCol, ChildTbl, ChildCol, Cast(ParentTbl + '.' + PatCol + ' = ' + ChildTbl + '.' + ChildCol As varchar(max)) As SQlString
From @SampleData
Where [Level Id] = 1
Union All
Select s.[Level Id], s.ParentTbl, s.PatCol, s.ChildTbl, s.ChildCol, c.SQlString + ' = ' + s.ChildTbl + '.' + s.ChildCol
From cte c
Inner Join @SampleData s On s.[Level Id] = c.[Level Id] + 1 And s.ParentTbl = c.ChildTbl And s.PatCol = c.ChildCol
Select [Level Id], ParentTbl, PatCol, ChildTbl, ChildCol, SQlString
From cte;
Tom